Columns | The LCGC Blog

In this LCGC Blog, Katelynn Perrault Uptmor discusses her time teaching undergraduates separation science, and what she and her students have learned through their time together.

The American Chemical Society’s National Historic Chemical Landmarks program highlights sites and people that are important to the field of chemistry. How are analytical chemistry and separation science recognized within this program?

In this LCGC Blog, Daipayan Roy and Muhammed Qamar Farooq of Amgen discuss the history and impact of supercritical fluid chromatography (SFC) throughout the years.

In this LCGC Blog, Kevin Schug discusses the potential machine learning has in helping predict physicochemical properties of molecules and optimizing chemical analysis processes.

In this LCGC Blog, Daipayan Roy and Muhammed Qamar Farooq of Amgen discuss the history and impact of supercritical fluid chromatography (SFC) throughout the years.

In this edition of The LCGC Blog, André Striegel provides advice on how to prepare for your first talk or presentation at a scientific conference.

In this edition of the LCGC Blog, Amber Hupp of the College of the Holy Cross provides advice for aspiring analytical chemists and shares accounts of other professionals.

In this edition of The LCGC Blog, Emanuela Gionfriddo discusses the two world-class scientists and trailblazer women in separation chemistry and the awards they received at Pittcon 2024.

Are you a chromatographer or a chromatography user?

In this edition of "The LCGC Blog," Jonathan Shackman discusses the differences between chromatographers and chromatography users, as well as advancements that have made chromatography a more accessible field.

Need help reaching your full potential as a separation scientist? A career development plan can help set a clear direction to reach your goals more effectively. In this LCGC Blog, we will cover why having a plan is important, what makes a good plan, and how to best use it.

In this LCGC Blog, the author explores stationary phases that incorporate permanent or induced charges within, or alongside, hydrophobic alkyl silica type bonded ligands.

In this LCGC Blog, Kevin Schug shares his plans for the future as a Fulbright–Palacky University Distinguished Scholar in the Czech Republic, and discusses why it is important to share analytical chemistry with communities around the world.

In this LCGC Blog, Muhammad Farooq shares some tips for entering different careers within the analytical chemistry industry.

Are you interested in ChatGPT's vast potential? Or are you getting tired of reading or hearing about ChatGPT?

In this LCGC Blog, André Striegel discusses common rumors about what and what not to do at academic conferences, to educate first-time attendees on what to expect.

This past spring, we convened a panel of six phenomenal separation scientists, where they gave their best advice for separation scientists, newcomers and veterans alike.

Are you interested by ChatGPT's vast potential? Or are you getting tired of reading or hearing about ChatGPT? If the latter, this blog post might give you some tips and tricks on taking advantage of ChatGPT while avoiding its application beyond its intended scope.

ExTech is the largest conference dedicated to extraction technology, a field within separation chemistry that has seen remarkable growth over the past three decades.

Pop quiz – can you define resolution? Would you be surprised at the number of correct answers? Which one is the best for chromatographers? In this LCGC Blog, we look at the various ways resolution can be interpreted scientifically.

This blog addresses the essential role software has in shaping the present and future of chromatography for the better.

In this LCGC Blog, Tony Taylor performs various experiments with ChatGPT to test how useful the AI technology can be in aiding chromatographers' work.

Manufacturing capillary gas chromatography (GC) columns is a very complex procedure, with many production factors to consider. In this LCGC Blog, Tony Taylor lists some of the vital components of the GC column-making process.

The level of uncertainty provided by most forensic laboratories for reported blood alcohol results has been woefully underassessed. Not only is this bad science, but someone’s civil liberties may be at stake.

In this LCGC blog, we reflect on the movement to make analytical chemistry more environmentally friendly, and how to potentially better those efforts for the industry's future.

In this LCGC blog, some words of wisdom are offered to help one avoid that panic situation of having to change the GC column or delay the analytical results.

The new General Chapter <621> does reflect the great work of the Pharmacopoeias in helping chromatographers to use more modern technology for their regulated methods, speeding up analysis, and reducing waste. The latest revision allows us to adjust column dimensions for gradient separations, which is a significant advance. Although these freedoms are welcomed, one must be very mindful of the requirements or limits of the allowable changes and the verification work that underpins our demonstration of equivalent performance of the adjusted method.

Undergraduate research and a job or jobs are not the same as an internship. Here's why.

Comprehensive two-dimensional gas chromatography (GC×GC) is becoming increasingly popular, but is still not used as commonly as it could be. That likely means that the technique is still not widely understood. This article is intended to begin demystifying GC×GC by presenting a simple explanation of how it works and its major benefits.

At the heart of most chromatographic analyses are the gravimetric and volumetric operations used to prepare samples, standards, and HPLC mobile phases.

I recently read a nice article from The Robot Report (1) that contrasted the performance of robots in industry against those of humans. The takeaways from the report are as follows.

What’s the fastest way to acquire a new chromatographic skill? The answer lies with those who are just beginning to learn.

It is a fact that most of us will be experiencing rising helium costs, and in some cases, caps on supply, or an inability to initiate new supply contracts from providers. Based on my own experiences, and those of colleagues and contacts, I’ve prepared what I hope is a succinct and focused guide on the factors one needs to evaluate to properly inform the decision to switch, and what to expect on the implementation journey.

Increased diversity in the workplace brings broader perspectives and innovation. Yet many chemical industries, including separation science, lack the diversity that is representative of the population. To fix this problem, we must start at the beginning of the pipeline.

Professor James Ephraim Lovelock, inventor of the electron capture detector and developer of the Gaia theory, died last month on his 103rd Birthday.

We continue our “Critical Evaluation” series with a consideration of liquid chromatography (LC) methods that use mass spectrometric detection.

Earlier this summer, separation scientists from around the world made their way to San Diego for the HPLC 2022 conference. What was it like being back to an in-person liquid chromatography conference?

We are investigating fundamental relationships between the structures of molecules and their interaction with different materials, in the context of on-line supercritical fluid extraction–supercritical fluid chromatography (SFE–SFC).

Separations science within microfluidics has already begun to make significant impact across any number of fields. But many times they are embedded within a larger system—their importance hidden or minimized.

In this next installment of our “Critical Evaluation” series, we will examine gas chromatography methods which use mass spectrometric detection (GC–MS).

Extraction-based sample preparation has been recognized as a significant step in separation science. To improve the sensitivity and selectivity of the extraction, some new approaches have been introduced, including those that employ an electric field. These electric field-assisted extraction methods create another dimension for sample preparation, and are compatible with miniaturized, portable, and multifunctional analytical platforms.

As chromatographers, our thoughts turn to the use of hydrogen as an alternative carrier gas, to ensure continuity of supply and reduce long-term costs.

It is of paramount importance that companies develop their in-house macromolecular separations expertise, not only polymer manufacturing companies but also those employing macromolecules for any of a host of applications, from drug-delivery and tablet coatings to ink-jet printer formulations and food additives, to name but a few.

This time of year tends to serve as a reminder that while women may be entering more degrees and careers in science than ever before, there is still a need to advocate for gender parity in many sectors.

The ability to predict issues and highlight unusual method parameters, before ever entering the laboratory, allows you to be alert for potential issues with a separation, or to change the method (where applicable) prior to initiating any experimentation. These detective skills, when applied in retrospect, are also invaluable for troubleshooting problems with the chromatographic separation or quantitative results.

An undeniable effect of the COVID-19 pandemic is that we have learned how to adapt (quickly) to sudden changes.

If your decision making relies on analytical chemistry, then you want to be confident that the measurements are an accurate representation of the matrix that is being analyzed, and that they are of “publication” quality. But how can you know for sure if the analytical laboratory that you’ve selected is producing reliable data?

In this month’s blog, we provide information about the Subdivision on Chromatography and Separations Chemistry (SCSC) of the Analytical Division of the American Chemical Society (ACS), sharing our main goals and introducing our newly appointed executive board members.

The quadrupole mass analyzing device is now accessible to many analytical chemists as a detector in either HPLC or GC instruments due to their increasingly accessible price point. While it’s not vital that we understand the working principle of these detectors, insight into their design and operation can help enormously when planning or optimizing analyses or troubleshooting issues.

The phenomenon known as the “green rush” outpaces all significant analytical market areas. Given all this excitement, it is worth stepping back to examine the overarching trends and nuances of the cannabis testing environment and offer some opinions about the key players and disruptive technologies gaining traction throughout this burgeoning marketplace.

In this series of blog posts, I’m going to explore how the challenges of adopting methods from the literature, or from internal or external clients, can often be made easier, and more enjoyable, by taking time for some detective work prior to even entering the laboratory.

With modern chromatography modeling software, is it time to hang up our laboratory coats? Is resistance to software solving separations futile?

The deficiency in method validation for forensics laboratories regularly manifests itself in two steps.

Electronic pneumatic controllers (EPC) were introduced into gas chromatography (GC) systems from the mid-1990s onwards and do an excellent job of regulating gas flow and pressure for GC inlets, columns, and detectors. Regular readers will know that, while I support innovation and improvements in engineering capability, I am inherently skeptical of anything with the “black box” tag and believe that unless we inherently understand how something works, we can neither fully harness the potential benefits, nor properly troubleshoot when something goes wrong. Therefore, read on as we open the lid and take a good look inside these particular black boxes.

In 2015, the American Chemical Society’s Committee on Professional Training added a requirement to the ACS degree certification program that undergraduates learn about macromolecules, supramolecular aggregates, and nanomaterials (MSN). This requirement can be met by a specialized course in these topics, but many programs are also choosing the distribute these topics across the curriculum.

I’m very much a “big picture” type of thinker. By that, I mean unless I can understand all of the working parts of a problem and understand how they interact, I find it difficult to decide the best approach to figuring out how to solve the issue.

I do not believe in classic linear separations anymore—further, I think separations science is wildly underdeveloped and under-appreciated.

Separation science is an intriguing and challenging (yes, let’s admit it) interdisciplinary field. Many of our daily rituals depend on effective chemical separations.

I’d like to concentrate on variables that can really impact our chromatography, but may be on hidden, supplementary, or advanced pages of our software, or may appear on the main software acquisitions menus, but are poorly understood or rarely altered. These variables are often not specifically referenced in laboratory methods documents or, if they do appear, are poorly understood.

Over the 17 years since the original Hydrophobic Subtraction Model for HPLC selectivity was published, those who curate the model have collected a huge amount of data as new HPLC stationary phases have been added. Analysis of this new data on almost 600 stationary phases has allowed us to update or adjust several of the stationary phase–analyte interaction terms within the model as well as adding one entirely new term to better describe the dipolar interactions with more modern stationary phases such as the pentafluoro phenyl-type phases.

Is there a secret formula to getting hired into a pharmaceutical analytical chemistry group? What skills are prized above all others?

Many of us have faced the situation where we have analytes that vary widely in their polarity or LogP(D) values and encounter issues with analyte solubility when choosing a suitable sample diluent for our high-pressure liquid chromatography (HPLC) analysis. The more polar analyte will favor aqueous solvents, and the less polar will be more highly soluble in organic solvent—so which do we choose?

Kevin A. Schug suggests that now is the time to fast-track industry–academic partnerships for greater sustainability.

Everyone who is reading this column is interested in chromatography, and I want to shine a light on the industrial side of the application space.

Ron Majors was the 2020 recipient of the Chromatography Forum of the Delaware Valley (CFDV) Award, which is given to those who have provided exceptional service for the Forum in addition to outstanding contributions within the field of chromatography. Readers of LCGC are well aware of his nearly 60 years of research and leadership in this area (1), but few outside the Delaware Valley region know of his decades of membership on the CFDV Executive Committee, including two terms as president. As part of this well-deserved honor, Ron gave a (remote) address to the organization in October 2020, detailing his many accomplishments in the field and summarizing the current state-of-the-art in high performance liquid chromatography (HPLC) column technology (2). However, it was his introduction describing the early days of HPLC that stood out to me, specifically a name I had not heard before: Elmar Piel. For this month’s blog post, I invited Ron to join me in writing a bit more about this scientist who may be unfamiliar to many chromatographers.

The question, which is often asked of our technical support and applications chemists, is one to which I often reply, in the words of John F Kennedy, "Ask not what your column can for you, ask what you can do for your column.” OK, JFK substituted “column” for “country” in his version of the quotation, but as you will see, it’s a very relevant premise!

In April 2020, on the heels of the pandemic shutdown, the price of crude oil fell to a negative value for the first time ever. The shutdown hit many oil and gas companies hard. But while companies lick their wounds and decide their next moves, an important concept called environmental and social corporate governance (ESG) has come greater into focus.

Here are 10 great tips for optimizing LC-Electrospray Ionization (ESI)-MS so that you achieve the best possible results every time. These tips and tricks have been collated by my colleagues to form a beginner’s guide to LC-(ESI)MS and as a primer for those who are already using the technique.

The separation science community is full of talented, productive, and innovative researchers of all genders, from diverse racial and ethnic backgrounds, working around the globe in academia and industry. Our awards should reflect this. It is one thing to say this. It is another thing to do it. But there are steps we can each take to ensure that our awards showcase the full range of separation science talent.

Capillary GC is renowned for being a ”high efficiency” technique, meaning that we typically see very narrow peaks within our chromatograms. This leads to the ability to separate many components in a reasonable amount of time, which is of course analytically advantageous.

Pretty much every commercial chromatography column has some sort of release testing done on it before it leaves the manufacturer. Just how valuable are those tests to the end user? Should column Certificates of Analysis go straight to the rubbish bin?

Oliver Napoleon Hill (1883– 1970) was an American self-help author once described as ”the most famous conman you’ve probably never heard of” (1 ). Conman maybe, but there is a quote of his that I believe to be particularly true when considering sample preparation for chromatography techniques; ”The one who tries to get something for nothing generally winds up getting nothing for something.”

In any given community, on rare occasions, leaders converge on a big idea. The development of such an idea alters the course of the community, in a way that is meaningful if it is lasting. It is my belief that the collective chromatography community is currently converging on a big idea.

The technology and resources available in this digital world have really pushed the way that we can (and now may have to) teach.

As described in last month’s blog post, the ongoing global pandemic has transformed the way that educators approach teaching analytical chemistry. As I reflect back on my own experience from the Spring 2020 semester, one positive aspect that has come from the seemingly infinite number of video meetings has been the opportunity to connect with colleagues that we might not consider if it weren’t for the “new normal” of working remotely.

Optimizing gas chromatography (GC) separations typically involves making some informed choices around stationary-phase chemistry and column temperature programs

As our academic year comes to end, I always take time to reflect on what I have learned in the past year. As an assistant professor in Forensic Sciences and Chemistry at Chaminade University of Honolulu, I take the opportunity to review my courses regularly and implement new tools. Some of them will be successful and others will not.

We are frequently asked about issues with reduced peak size in gas chromatography (GC), and I’m guessing this is related to just how difficult this problem is to troubleshoot. There are so many potential causes that an inexperienced GC user may not know where to begin the troubleshooting process. Fear not. What follows is our logical guide to locating and fixing the issues with loss of sensitivity, and we’ve tried to cover as many of the instrument and application issues that we can think of.

My initial inclination was to write about something other than the current status of life, given the threats of coronavirus. However, after a month extension to the shelter-in-place was ordered by the U.S. government this past weekend, and after various e-discussions with friends and colleagues throughout the world who are experiencing similar challenges, I felt I might have something to offer to make life easier.

Most HPLC columns are packed with silica onto which some form of hydrophobic ligand is bonded – these columns form the vast majority of those used for modern reversed phase HPLC.

My initial inclination was to write about something other than the current status of life, given the threats of coronavirus. However, after a month extension to the shelter-in-place was ordered by the U.S. government this past weekend, and after various e-discussions with friends and colleagues throughout the world who are experiencing similar challenges, I felt I might have something to offer to make life easier.

Peak tailing is a problem that is regularly encountered in capillary gas chromatography (GC). It can cause issues with resolution and peak integration, affecting both qualitative and quantitative analysis. In this first of a series on GC diagnostic and troubleshooting, discover how best to identify the source of the issue, and find suggestions on how to prevent or fix the problems that underly the issue.

The 44th International Symposium On Capillary Chromatography (ISCC) and 17th GC×GC Symposium will be held at the Palazzo dei Congressi, in Riva del Garda, Italy, from 24–29 May 2020.

The selectivity (α) of an analytical system describes the ability to discriminate between sample components based on differences in chemical and physical-chemical properties.

It was a pretty significant fight to get our most recent paper into the scientific literature. But, after five reviewers opining and four submitted revisions later, we were able to publish a very unique piece of work characterizing anecdotal claims of groundwater contamination in shale energy basins across the United States.

I’m frustrated with static headspace sampling!

Looking back, the start of my penning of blog articles matches quite well with the start of efforts to investigate the potential environmental impacts of unconventional oil and gas extraction, and the formation of the Collaborative Laboratories for Environmental Analysis and Remediation (CLEAR; http://clear.uta.edu) at the University of Texas Arlington. It also well coincided with my effort to begin some outside consulting activities, predominantly the review of forensics evidence for blood alcohol determination. Both of these activities have blossomed considerably in the past seven years, and it has become interesting to contemplate the most rewarding way to spend my time going forward.

I’ve been dealing recently with issues in the laboratory when using ammonium acetate buffers, including surprising rises in HPLC–MS back pressures when starting the instrument after overnight storage, as well as difficulties with MS sensitivity.

I run into scientists all the time who have never heard the term exposome. Most are not intimately connected in the analytical world; these days, analytical scientists seemingly expect “ome” and “omics” to be tacked onto pretty much anything.

In HPLC Diagnostics Skills Part I we looked at baseline issues, and we continue here with HPLC peaks and in particular the skills required to identify tailing peaks, the causes of peak tailing, and most importantly, how to fix the issues that give rise to this peak deformation.

Theoretical computations can contribute input into experimental determinations.

I wanted to produce a checklist for preparation of a GC or GC–MS system prior to analysis, referencing the actions, checks, tools, and consumable items that might be required.

Traveling to interesting places for conferences and hearing new ideas is certainly one of the most enjoyable aspects of a faculty position. Recently, I attended the 16th International Interdisciplinary Meeting on Bioanalysis (CECE 2019) in Gdansk, Poland. I was absolutely delighted both by the city and the scientific quality of the meeting.

The improved performance of chromatographic detectors, most notably mass spectrometers, has enabled many advances in analytical science, however, one such advance may be given less prominence than perhaps it should.

In an effort to better understand the current application potential of microscale liquid chromatography (micro-LC), I picked up a few recent review articles from the literature. What one immediately appreciates from glancing through the literature for such information, is that there are a lot of different configurations and alternative formats, which can be placed under the micro-LC umbrella.

Our recent discussion on the use of hydrogen as a carrier for gas chromatography applications elicited many questions and comments, however one common question was “what are the considerations for using hydrogen carrier with MS detectors?”

Recently, I was honored to attend the 2019 Shimadzu Global Innovation Summit, hosted by Shimadzu Corporation in Kyoto, Japan. The focus of this meeting was to highlight innovation at the interface between analytical chemistry and medicine.

As I receive reports from clients in Europe and the United States that helium prices are once again increasing, and warnings are being given regarding yet another laboratory-grade helium shortage, my thoughts turn once again to the use of hydrogen as an alternative carrier-gas for gas chromatography.

As someone who has been associated very closely with poster presentations, I have to say, it is time for a change.

Exosomes are small lipid membrane-bound extracellular vesicles, on the order 30 – 150 nm in diameter, which are shed by normal and tumor cells in the body. They are circulating within your body and can be isolated from virtually any biological fluid. Exosomes released from tumor cells have been shown to be enriched in certain proteins. These nanobodies hold significant promise for the discovery of cancer biomarkers, for cancer diagnosis and prognosis, and for biomarker quantitation.

Modern HPLC method development is dominated by a small number of pH adjusting reagents and buffers that are prevalent even when the method uses UV detection. This is driven primarily by the requirements of mass spectrometry.

We have been working to develop the use of liquid chromatography–triple quadrupole–mass spectrometry (LC–MS/MS) for quantification of intact proteins from biological fluids.

To answer the question "Is there a good flow diagram I can use for GC method development?" please see below for our first attempt at something suitable, in the form of stepwise decision trees and flow diagrams.

As we close in on a little more than a month to go before the 43rd International Symposium on Capillary Chromatography and the 16th GCxGC Symposium (ISCC & GCxGC 2019; www.isccgcxgc.com), May 12 – 17 in Ft. Worth, Texas, my excitement burgeons. All of the groundwork has been laid to provide forums for presenting and discussing the latest advances in capillary and comprehensive separations science.

In the late “noughties” we couldn’t avoid the webinars, seminars and online calculators which were being released by HPLC column manufacturers to extol the virtues of the “new” core-shell particle morphology that promised high performance at lower back pressures.

Virtually exclusively, liquid chromatography–mass spectrometry (LC–MS)-based assays for protein quantitation rely on bottom-up strategies, where the protein is initially digested into constituent peptides during sample preparation. Top-down intact protein quantitation, especially using affordable, low resolution triple quadrupole (QQQ) mass spectrometers, has been largely unexplored.

Just as medical practitioners are able to discern worrying features from a variety of medical physics devices (electrocardiogram, electroencephalogram, ultrasound, for example), we need to develop the skill to identify worrying symptoms from our HPLC instrument output.

If you have a method or process that involves a number of different variables, multivariate optimization approaches can provide a faster route to optimum conditions and can lead to a more reliable outcome than using a one-factor-at-a-time approach. With a little study and practice, students and researchers can apply these optimization techniques, even if a complete understanding of the underlying statistical treatments is not immediately apparent.

You may be one of the many analytical scientists who look with envy at those laboratories who are equipped with sophisticated automated HPLC method development systems. These systems are indeed very nice and can be very efficient in narrowing down choices, however, they aren’t a universal panacea and one can achieve a lot with a simple, paired down approach.

In 2009, the founders of VUV Analytics, Inc. approached my group about the potential of coupling a vacuum ultraviolet absorption spectroscopy detector to a gas chromatograph (GC–VUV).

UV detectors are undoubtedly the most frequently used type of detector with HPLC systems, and I predict this will continue for many years, despite the rise of the modular mass spectrometric detector.

From May 12 – 17, 2019 at the Hilton Ft. Worth in Ft. Texas, I will be co-chairing (together with my colleague Prof. Dan Armstrong) the 43rd International Symposium on Capillary Chromatography (ISCC) and the 16th GCxGC Symposium. I am writing to tell you this not only because organizing a meeting is quite an undertaking, but also because I am really excited about how this event is shaping up.

I think its fair to say that there has been a paradigm change in the way we approach mobile-phase design for HPLC in recent years.

Unconventional oil and gas (UOG) extraction is a multistep process that involves horizontal drilling, hydraulic fracturing, and massive infrastructure to handle fossil fuel resource recovery and associated wastewater generation.

In my previous blog, I discussed the possibility of backflash in splitless GC injection and its effect on quantitative reproducibility and carry-over.While much is written in the literature on optimization of splitless injection conditions, little is available on the implementation and optimization of increased head pressure (pressure pulsed) injection, so we will concentrate on this aspect of injection optimization.

For an international conference, highlighting the diversity of research, and the people performing it, is important. Diversity comes in a lot of different flavors: Industrial vs. academic; different cultures, values, needs, and resources; age and gender; among others. Representatives from all different backgrounds and experiences should be given a voice.

Let’s first properly define carry-over in the context that I’d like to discuss here. An injection is made and a chromatogram obtained. On injecting a “blank” as the next injection, one or more of the components of the previous injection appear in the “blank” chromatogram.

I just finished a 10-month stint as Interim Associate Dean for Research and Development in the College of Science at The University of Texas Arlington. I was afforded that opportunity when some restructuring in another college left a temporary vacancy, which I was asked to fill. I certainly considered it an honor to be asked to serve in that role, but the temporary nature of that role also piqued my interest. For me, it seemed like a chance to do an internship in administration, to see if I liked it or not. I worked with great people, I did not really like the role.

Chromatographic methods often require that the analyte response is calibrated (and validated) over a wide concentration range when the analyte concentration in the sample is either unknown or is expected to vary widely. Bioanalysis, environmental, and clinical applications are just a few examples of where this may be the case.

For several years, our group has been working on a concept that we have termed multipath liquid chromatography (LC). The main idea is to target multiple classes of compounds following a single injection of a sample, the components of which are segregated on-line and directed to separate appropriate paths for simultaneous separation; the streams are then recombined for detection. I believe that this approach would be powerful for biomarker quantitation, where it would be more informative to track both metabolite and protein biomarkers to better define a disease state, or in the case of antibody–drug conjugate (ADC) development, where the metabolism of the ADC might involve understanding both the levels of the released drug and the remaining protein.

It is often possible to achieve better sensitivity and lower limits of detection and quantitation using standard gas chromatography (GC) equipment-here I’m referring to a standard split/splitless injection port and a Flame Ionization Detector (FID). Paying attention to some of the fundamental variables as well as some of the more esoteric considerations can lead to much improved method performance.

If given the need to determine drug A or its metabolite in blood, 99% of the time I would choose to start with liquid chromatography–mass spectrometry (LC–MS).

HILIC is not straightforward and there may be a number of mechanisms in play which need to be considered.

What type of mass spectrometry (MS) instrumentation provides the best specificity during trace quantitative analysis from complex mixtures?

It’s excellent to see that compendial authorities are considering updating “allowable change” regulations, and the updates to allow changes to gradient profiles certainly open up a whole new world, but there are some reservations around the new restrictions on allowable changes to stationary-phase chemistry.

One of the initiatives that the SCSC oversees is the nomination process and awarding of the Satinder Ahuja Award for Young Investigators in Separation Science. Where are all of the young investigators in separation science? Certainly, those that have been honored to date have been worthy; however, there must be more eligible parties out there.

What is the chemistry of this phase? What are the mechanisms of interaction with the analyte and hence how is retention and selectivity gained from this phase? How can we troubleshoot separation problems or develop suitable methods without a good knowledge of the bonded phase chemistry?

I do not remember the application, but I remember very clearly Professor McNair telling us that soil is one of the most challenging sample matrices, if not the toughest, from which to perform analytical determinations. Sources indicate the composition of soil ideal for growing plants to be 25% air, 25% water, 45% minerals, and 5% organic matter. That does not seem like a daunting makeup, but the reality is that the relative proportion of the constituents can vary dramatically.

The overriding majority of articles on problems with the technical transfer of HPLC methods ultimately focus on differences between HPLC dwell volumes. However, as the title suggests, there are many more issues which can cause problems in the transfer of HPLC methods, and I wanted to highlight some common issues that come across my desk, in the hope that it will help you avoid these problems in your own practice.

Several years ago, I would have held the stance that environmental analysis was fairly boring. How complicated can water be? I am not ashamed to say that was a naïve view. It is clear from our research and related research by others on similar topics that much more work in these areas is needed. Standard methods cannot solely accommodate the growing list of targets and the multitude of unknowns associated with complex samples taken from the interface between the petroleum industry and the environment.

I'm often asked to help with the development of column "screening" platforms and automated development systems. While this covers a large amount of analytical science there are some common elements to this type of approach, perhaps the most important of which is column selection. Unsurprising given that "selectivity" is the most powerful tool we have in chromatography and we all know that the best way to optimize selectivity is to choose the most appropriate stationary phase.

I always think of a conference presentation to be like a rock band concert. Sure, the band is going to play some of their biggest hits, but they also want to propagate their new stuff. More importantly, they want to put on a show so that people are entertained. I do think there should be more emphasis on entertaining the audience during oral presentations.

Sometimes troubleshooting a separation can rely upon the end user spotting subtle clues within the chromatogram, and at other times the visual signs can be much more obvious. To start the New Year, I wanted to share some of the most common issues that we see with peak shapes in gas chromatography in the hope that if you spot some of these in your own work, you may be able to intercept problems and deal with them more effectively.

Two things were surprising about some recent research we reported. First, with regard to chemically impaired groundwater quality, it may not always be the chemicals that are most worrisome for human health impacts. Second, the primary methodology we used in that work for microorganism identification, matrix-assisted laser desorption–ionization mass spectrometry (MALDI-MS), is a vastly underappreciated tool, especially outside the clinical realm in areas such as environmental monitoring.

It’s very easy to be comfortable with what you have. It’s only when we realize what could be, that we become interested in changing things.

When I want to hear some humorous stories, there are few friends in the instrument manufacturing and sales business I can contact. If I ask them about their recent experiences with the cannabis industry, their stories will cover topics ranging from instruments purchased using duffel bags of cash (cue images of large men in suits and sunglasses packing heat) to recent college graduates who cleared $25 million in their first year of business selling cannabis butter (cue images of large men at breakfast laughing uncontrollably).

I hear the words “struggling for sensitivity” so often when speaking to folks using LC–MS for bioanalysis, environmental analysis, metabolomics, proteomics, and a host of other applications where target analytes are present at low concentrations in complex matrices. We spend fortunes on MS/MS instruments to increase specificity of detection in order to improve sensitivity. Some of us go to great lengths to optimize sample extraction and HPLC conditions in order to minimize matrix suppression effects and improve specificity and hence sensitivity.

The presence of capable students and researchers, each with a technical niche to offer, prepares us for future opportunities. On top of that structure, we also aim to maintain this mindset for our instrument selection before beginning projects. The installment of core labs at UT Arlington (www.uta.edu/sirt), making a wide range of instruments available to all research groups, has allowed our students to brainstorm about which instrument is the most appropriate for a specific analysis rather than how to make a measurement work with a given instrument.

Data validity and a thorough understanding of the results that we produce should be of great interest to us all. Here's why.

Internal standards (IS) are commonly incorporated into quantitative methods to increase accuracy and precision. An IS is a compound that is different than the analyte of interest, has similar physicochemical properties to the analyte, and is added to samples, calibration standards, and quality control samples in a known quantity. It should not be present in the sample, it should be available in high purity, and it should be easily differentiable from the analyte of interest.

The ability to rapidly screen stationary phases through column-switching capabilities provides significantly greater efficiency in method development than was previously possible. The approach does require some additional hardware and software. And, while such capabilities may limit the ability to expand one’s literary knowledge during excessive months in the laboratory developing separation methods, real progress to key decision points for method optimization can be realized instead.

With the increasing proliferation of UHPLC, with its very much reduced extra column volumes, is the concept of dwell volume still relevant? Indeed, in your world, was it ever relevant at all?

As the fall semester starts, I begin my 13th year as a chemistry professor. Let me get right to the point-if you do not love this job, you will hate it!

The ability to rapidly screen stationary phases through column-switching capabilities provides significantly greater efficiency in method development than was previously possible. The approach does require some additional hardware and software. And, while such capabilities may limit the ability to expand one’s literary knowledge during excessive months in the laboratory developing separation methods, real progress to key decision points for method optimization can be realized instead.

Until recently, I hadn’t heard of ternary or quaternary gradients being used for many years. They have gained a reputation for being somewhat difficult to reproduce-less robust, if you like.

Hydrophilic Interaction Chromatography can be a very useful tool in our analytical armory, however there are some practical peculiarities to this chromatographic mode which need to be understood in order to ensure success. 

I believe that the term “top-down proteomics” holds a particular connotation with respect to the use of ultrahigh-resolution mass spectrometers in people’s minds. And rightfully so. If one is to determine with confidence the sequence and charge state of a particular fragment ion generated in the gas phase, then high mass accuracy is a must. From the discovery side of things, where qualitative analysis is most important, this is not likely to change. However, when you turn to quantitative analysis, where you want to now monitor levels of a particular protein biomarker for the purpose of disease diagnosis, prognosis, or treatment, then invariably bottom-up strategies are the norm. Protein quantitation using top-down strategies, especially on low-resolution triple-quadrupole systems, have been largely ignored, until recently .

I’m often asked “what reproducibility should I expect to get from my [insert instrument manufacturer and model]?” So, most folks are referring to the repeatability aspects of precision, as in: “what relative standard deviation (usually expressed at %RSD) for peak area or quantitative result should I be able to achieve from repeat injections from a single vial of sample?”

Precise and accurate quantitative analysis based on chromatographic measurements has historically relied very heavily on careful peak integration. Seasoned analysts know that while automated algorithms exist in modern chromatography software, it is a best practice to manually check that the integration points-the points at the beginning and end of a peak, between which the peak will be integrated to obtain a peak area-are appropriately specified.

I guess we have all had the issue at some time or other. A blank injection of eluent (or a zero volume dummy injection) gives rise to discreet peaks on the chromatographic baseline which may interfere with analyte peaks or increase the complexity of the chromatogram obtained, especially when performing trace analysis.chromatogram obtained, especially when performing trace analysis. Of course this is an undesirable situation and one which can be difficult to understand or troubleshoot as, if we didn’t inject anything, how on earth do we end up with discrete beaks in the blank chromatogram? The secret to understanding the phenomenon lies in understanding the mechanisms of gradient of HPLC.

As part of the Earth Day celebration in Dallas, Texas, last month, the Collaborative Laboratories for Environmental Analysis and Remediation (CLEAR) at U.T. Arlington hosted the first annual Responsible Shale Energy Extraction (RSEE) symposium (www.shalescience.org). We had an exceptional range of speakers who conveyed all sides of the issue, including U.S. Secretary of Energy Rick Perry and atmospheric scientist Dr. Katherine Hayhoe from Texas Tech University, one of Time’s top 100 most influential people. We had representatives from major oil producers, environmental groups, land management groups, water recycling service companies, and scientists conversant on many key issues related to unconventional oil and gas (UOG) extraction. Even though we have been very involved in this conversation for the past several years, several points stood out.

As I’ve written previously, our Nirvana in HPLC column selection would be to enter the structures of our analytes and have a database tell us the column and mobile phase conditions that we should use to carry out the separation successfully. Although I know of several groups who are working on this, in practice we are still a long way from realizing this goal.

I have written previously about occupying the middle ground in the debate over the environmental implications of unconventional oil and gas extraction operations. It seems we are just in the right place, when we are criticized and praised at separate times by proponents of both extreme views-namely those who think UOG is perfectly safe and those who think it cannot be done without ruining the environment.

A short treatment of what to consider when choosing the appropriate sample solvent so you can be better informed when developing, optimizing, transferring, or troubleshooting your GC methods.

Students who have an internship on their resume, and are seeking jobs in a particular sector, are doing so with an informed opinion. While an internship comes in many forms, that real-world experience has provided a clear touchstone of understanding of what it would be like to work in a given sector.

This time I’m going to be looking at how to get the most from your GC–MS (Gas Chromatography–Mass Spectrometry) system, and I intend to keep things as simple as possible, however I also make no apology in the fact that some of the concepts may be beyond your current understanding. My intention here is to explain some of the basics so that you will be able to use your instrumentation to best effect.

For the most part, we are still instructing undergraduate students in the same way as when I went to school, and I think this is a disservice to the students and to the nature of chemistry. No wonder chemistry programs have trouble attracting students compared to other science disciplines, like biology and psychology. Students will take general chemistry, but they cannot see where it may lead. I want to change that.

As I wrote the title of this LCGC Blog instalment, I could not help but wonder where the cliché “more than one way to skin a cat” came from. Turns out it is from Mark Twain in his 1889 work, A Connecticut Yankee in King Arthur’s Court. I have never read that book, but I certainly have heard this saying used more than once - even if it might offend some cat lovers. Of course, it means simply that there is more than one way to do something.

Many of our instrument techniques rely on a calibration in order to relate the detector response to the amount of analyte within our sample.

In order to contemplate and test your knowledge, Kevin A. Schug provides a sampling of some of his chromatography true–false questions from his senior-level Instrumental Analysis course.

Our technical support center deals with many issues regarding irreproducibility of retention and selectivity in reversed phase HPLC. Very often, the problem lies in poor equilibration of the HPLC column between injection, which in gradient HPLC can affect the separation selectivity as well as analyte retention.

In 2011, when we first began field and laboratory studies to help assess the potential environmental impacts of unconventional oil and gas extraction (UOG), there was very little literature on the subject. Further, the polarizing nature of the topic made it quite difficult to navigate the middle ground. While some voices contended that UOG was perfectly safe, others insisted that it should be banned in its entirety because it is destroying the environment. As with any topic that is both complex and elicits the attention of a large number of people (like our past election or politics, in general), my skepticism forces me to believe that the answer actually lies somewhere in the middle of extreme views.

As we enter the Generalization phase of the industrialization of Analytical Science, we find ourselves striving for the generic in as many areas as possible.

As I wrote the title of this month’s installment, I could not help but wonder where the cliché “more than one way to skin a cat” came from. Turns out it is from Mark Twain in his 1889 work, A Connecticut Yankee in King Arthur’s Court. I have never read that book, but I certainly have heard this saying used more than once-even if it might offend some cat lovers. Of course, it means simply that there is more than one way to do something.

Kevin A. Schug reveals the major method validation protocol deficiencies he discovered when he reviewed a blood alcohol investigation and discusses how matrix effects possibly resulted in blood alcohol concentrations being over-estimated, resulting in a potentially significant injustice.

I started my career working in a Quality Control laboratory. I'm familiar with the constraints that must be imposed to ensure consistent global standards and the pace at which change can be implemented without loss of control either within a business or across an industry. OK-scene set.

I am quite excited about some recent work we and others have performed related to fuels analysis using gas chromatography and vacuum ultraviolet spectroscopy (GC–VUV).

I’ve often written about the “lazy” chromatography which has swept through our industry, whereby 0.1% (w/w or w/v!) TFA or Formic acid is used to “buffer” the eluent system well away from the pKa of analyte molecules, leaving most acidic analytes in the ion suppressed form and most basic analytes in the ionized form. This approach avoids having issues with retention time drift and effectively eliminates pH as a variable used to control retention or selectivity for separations involving ionogenic analytes.

Kevin A. Schug discusses how matrix-assisted laser desorption–ionization time-of-flight mass spectrometry (MALDI-TOF-MS) is one of the most versatile tools for fingerprinting mixtures.

In a recent review of blood alcohol casework performed by a forensics laboratory associated with a major metropolitan police force, I was again disheartened to find major deficiencies in method validation protocols. In this case, the analysts failed to check whether aqueous solutions for calibration and quality control were reliable surrogates for real blood samples.

I’ve done that thing where I’ve stated a very interesting title-I hope I can deliver something which lives up to it. I dislike it when people “overstate” their talk or poster titles at conferences to draw me in and then don’t deliver against the promise-I’ll let you judge how we go here.

Top-down protein quantitation, especially using triple-quadrupole MS, but even in general, has hardly been pursued. To help fill this gap, we recently reported a systematic investigation of intact-protein quantitation using multiple reaction monitoring (MRM) on a triple-quadrupole MS system, and we believe that this approach can be a promising alternative route to consider going forward.

Kevin A. Schug considers what the study of chemometrics and experimental design statistics can add to an analytical chemist’s work. Do analytical chemists lack an appreciation for the mathematical and statistical tools used to tease out important information?

The title of this piece may have put you off reading it – in which case you won’t be insulted when I say that even the most experienced gas chromatographers often fail to install columns in the best way possible.

Matrix-assisted laser desorption–ionization time-of-flight mass spectrometry (MALDI-TOF-MS) is actually one of the most versatile tools for fingerprinting mixtures.

I believe that most analytical chemists do not appreciate what the world of chemometrics and experimental design statistics can add to their work.

Not every method is as we would hope it would be. Some methods come to us in imperfect form and we have to live with them, while others are difficult separations and, by necessity, need to be developed using close control of several variables such as eluent pH, eluotropic strength, ionic strength etc.

In 2009 I wrote an article on the emerging field “Bio Chromatography,” which for a small molecule analyst such as myself, perfectly described the situation. I realize that the separation of biomolecules had been happening for many years, but the expansion and development of protein based therapeutics from that point onwards has seen an avalanche of developments in instrumentation, sample preparation, and column technologies the like of which I have not seen in my 30 year career.

Compared to the magnitude of unconventional oil and gas development activity that has been performed by industry, the amount of research to assess its potential environmental impact has been miniscule. Can the process have a deleterious impact if not well managed? Can it be performed in a responsible manner?

I often get asked about the other important aspects of “screening” in HPLC, which include the mobile phase composition, gradient parameters and flow rate – so that’s the theme of this installment.

Here, I will attempt to convey a few basic but critical concepts when getting started in the development of a new LCxLC method.

I’ve been talking about ‘ToolKit’ method development platforms a lot lately and I have to say I’m not sure we are making the most of this approach.

What is required to produce a highly efficient modern high performance liquid chromatography (HPLC) system/column combination? This instalment of the LCGC Blog explains more.

The literature on reversed-phase liquid chromatography of proteins is reasonably well developed, but not taught in the college classroom to a significant degree. So I would like to focus on a stoichiometric displacement model for reversed-phase LC of proteins that I found to be particularly insightful from a practical standpoint.

If you don’t examine your LCMS data closely, you could be missing some of these effects, and those problems with your quantitative data will never be fixed.

Food analysis provides a rich sample matrix with many compounds of interest for analysis to contemplate-but one must always take care that the right tool is chosen for the desired task.

Some modern HPLC systems resemble spacecraft in terms of their technology, designed as they are to operate to the highest efficiencies, compared to traditional systems.

Column overload is a very commonly encountered issue in gas chromatography (GC) for beginners. Changes in peak symmetry, generally observed as peak fronting, can be subtle in the sharp peaks generated by GC, but the result can be significant shifts in retention times, loss of resolution, and error in peak integration. LCGC Blogger Kevin Schug explains more.

After 10 years at U.T. Arlington, I have decided it is time to take one of the best opportunities afforded to researchers in an academic faculty position-to travel abroad and assimilate new techniques into my repertoire to enhance future research activities.

There has been much written about the use of nitrogen as a carrier gas for capillary GC. Formerly, to say it wasn’t any good. Latterly to say that it’s pretty good and a better alternative to Helium than hydrogen from a practicality standpoint.

It is much more efficient to screen column chemistries to achieve optimum separations for a set of target analytes, than it is to play with different mobile-phase conditions on a single column. Kevin Schug explains more.

LCGC Blogger Tony Taylor offers some simple visual methods to assess column performance.

They say a picture paints a thousand words… This month I’ve taken inspiration from a recent webcast, presented at www.chromacademy.com, in which I presented real data from our work that represents some ‘classic’ GC problems.

Column overload is a very commonly encountered issue in GC for beginners. Changes in peak symmetry, generally observed as peak fronting, can be subtle in the sharp peaks generated by GC, but the result can be significant shifts in retention times, loss of resolution, and error in peak integration.

Kevin Schug discusses why we need a comprehensive study of unconventional oil and natural gas (UOG) extraction processes.

A client asked me recently for a quick but "as optimized as possible" separation for some monoclonal antibody (MAb) characterization (digest) samples using LC-MS. The samples had been prepared and were awaiting analysis-typical forward planning! Actually his internal analytical department had changed their priority and he was left hanging.

If you want to improve analytical methods to make them better, the sample preparation step is probably one of the best steps to target.

Useful equations to improve the robustness of your separations.

There is a shortcoming in our current educational system. There is too much rote learning, and not enough time given to let science-minded students explore a topic. Overall, when students ask their own questions (not ones given to them by instructors), they become more invested in finding the answers.

When was the last time you reported your results with an estimate of the error associated with the data? You don’t need to because your method is performing within the levels defined by various agencies and which were confirmed by your validation and your daily QC checks. The person for whom you are producing the data is aware of these tolerances and therefore inherently appreciates the associated precision of the data and can make judgements based on this. Not in the world I work in!

We recently published a study of water quality from 550 water wells in the Barnett Shale of North Texas. Using a suite of analytical techniques, we were able to find new evidence of the potential impact of unconventional natural gas extraction on environmental quality.

LCGC Blogger Kevin Schug has uncovered some surprising knowledge gaps in method validation and forensic analysis.

Using ESI-MS to perform quantitative binding analyses and determine association constants depends on the ability of the ionization process to preserve the system equilibrium.

If you use SPE in your work, then most likely it’s very important to the success of your applications and it’s proper implementation will be key to the performance of your analyses. However, SPE protocols are “variable in quality” (I’ve been as I kind as I can there!) and this variability appears to come from some common issues, misunderstandings and, frankly, ignorance of the mechanisms which are in play.

LCGC Blogger Tony Taylor presents his eight steps for improving your solid-phase extraction (SPE) results.

Once you have mastered the terminology and symbology the actual mathematics for the models and approaches used at the level which is useful to practicing analytical chemists is really very straightforward indeed.

For the analytical community, method validation in some form or another is a natural extension of best practice in the analytical laboratory. However, the notion of method validation, and many aspects of detailed forensics analysis, are not well understood by most lawyers and judges.

Now that I have been at UT Arlington for 10 years, I have had many opportunities to refine my own approaches to teaching, in hopes that the learning curve to achieve meaningful learning for students is not as steep as the one I had to manage.

I got into a discussion with a learned colleague recently regarding the relationship between peak height and flow rate in gradient HPLC. We haven't really resolved the discussion, there are suggestions regarding "peak focussing," the number of column volumes in relation to the gradient volume (number of column volumes per minute), increases in efficiency etc.

All sample preparation adds the potential for error to the analytical protocol, so choosing less-complicated techniques will help to reduce inherent error.

What if we could make the troubleshooting poster on the laboratory wall come to life? What if we could build an engine which figured out the most likely causes of groups of symptoms and offer these up as a prioritised list for folks to work through and give them supporting information on each problem, why it occurred, how to fix it and, crucially, how to avoid it happening next time?

CLEAR is an endeavor to create a consortium of experts interested in building and propagating activities related to the assessment of the potential impact of industrial activities on the environment, as well as the creation of new solutions to mitigate problems associated with these activities.

There are many aspects of analytical science which abound with myth and legend – but gas chromatography – mass spectrometry (GC-MS), and more specifically the electron ionization (EI) process, stands out as the technique which has given rise to the largest number of ‘urban myths’ and misunderstandings.

In this blog installment, I would like to share a little advice with those of you who are attending your first major conference.

There are often times in my work when I need to 'mess about' with column dimensions and particle morphologies. For 'mess about' read improve or transfer.

I have been at The University of Texas at Arlington for almost 10 years, and I have taught approximately seven different classes in my time here. Yet, the one that I have had the most opportunities to teach, and the most time to reform, is our junior/senior-level Instrumental Analysis (IA) course.

LCGC Blogger Kevin Schug offers his insights into superficially porous particles (SPPs) versus fully porous particles (FPPs).

Choosing the correct column selectivity and dimensions is fundamental to successful gas chromatography method development.

If you do Gas Chromatography, then you will have undoubtedly conditioned a capillary GC column ready for use after a period of storage or before first use.

I have had enough conversations with experts in the field of high performance liquid chromatography (HPLC) stationary-phase supports to know that there is more to the increased efficiency provided by the use of superficially porous particles (SPP) compared to fully porous particles (FPP) than simply mass transfer effects. Yet, I would argue that this is still one of the biggest misconceptions propagated by some members of the chromatography community.

LCGC Blogger Tony Taylor asks if we are too scared to properly explore selectivity options in high performance liquid chromatography (HPLC).

In this issue – I hope to outline some 'small bolts' that are commonly ignored in everyday chromatography and mass spectrometry - instrument settings that I have to come call 'lock and leave' parameters. We can generate data without changing them or paying them any attention, but how much better could our data be if we bothered to optimise them.

A program was formulated to help educate public opinion leaders on the fundamentals of unconventional natural gas and oil extraction, to convey the current state of research on the topic, and to disseminate and discuss prospective regulations that have been formulated over the past two to three years.

A recent increase in research on the impact of unconventional oil and gas (UOG) extraction is welcomed by Kevin Schug. He explains more in this latest LCGC Blog instalment.

Much has been written about options for increasing efficiency in HPLC ? primarily through the use of core shell and sub 2 ?m particles, which have been used to increase efficiency, speed up separations or increase peak capacity. However, many separations can only be effectively improved, by optimising selectivity ? resolution is a function of selectivity, efficiency and retention, with selectivity being the most effective at achieving good resolution.

I will preface this blog installment by saying that I am not an expert on separation of proteins, but I am learning. What I do understand are the fundamentals of chromatography for small molecules. This information abounds, but it is much more difficult to find the same level of information for biomacromolecule chromatography.

Why would one want to use a mobile phase containing 100% water? Usually to wash the analyte or old mobile phase from the column (stationary phase surface) or to help retain analytes which elute quickly using mobile phases containing only very small amounts of organic solvent (usually highly polar analytes).

Unconventional oil and gas (UOG) extraction, which includes processes such as horizontal drilling and hydraulic fracturing, has created major positive geopolitical and economic advantages for the United States.

Most of us who have used UV detection for HPLC analyses consider them very straightforward and find they produce fit for purpose data whenever we need them to.

Gas Chromatography with Vacuum Ultraviolet Absorption Detection

LCGC Blogger Tony Taylor provides his impartial guide to liner selection that is representative of the considerations in modern capillary gas chromatography (GC).

When a scientist needs to search through scientific literature, which is the preferred search engine? While there is quite a bit of variety in available search engines, LCGC Blogger Kevin Schug has a definite preference. Here's what it is, and why.

When you begin to now combine advances in superficially porous media to achieve high efficiency with novel and predictable new stationary phases to achieve high selectivity, then it sounds like the evolution of HPLC and UHPLC phases over the past decade or more has brought some exciting new possibilities.

Is 0.1% TFA (aq) / 0.1% TFA in acetonitrile the ultimate robust HPLC mobile phase? Maybe not...

Much has been written about column overload, however, I've seen many instances lately in which overload may not be instantly recognized, or causes problems that may not normally be attributed to overload. Therefore, I wanted to explain how to spot and deal with different types of overload situations.

If you ask scientists, it does not take long before you realize that there is quite a bit of variety in the different search engines that they prefer.

The International Symposium on Capillary Chromatography (ISCC) and GCxGC Symposium combined conference provides an excellent combination of high impact, cutting edge science, and a great social program in an interesting venue. Kevin Schug shares his thoughts about innovations in gas chromatography presented at this year's conference in Riva del Garda, Italy.

When developing a separation, some fundamental choices need to be made on how we might achieve the separation we require - primarily the mode of chromatography used and the way in which we intend to control and optimise the retention and separation (selectivity) of analyte components.

Many troubleshooting investigations in chromatography often don?t lead to a single causal factor. Often, the reason for problems or lack of method robustness are related to many small ?contributory factors? and this is particularly true of the problems associated with sample introduction in capillary Gas Chromatography.

Solid-phase extraction (SPE) is a versatile and reliable technique that is often used for sample cleanup and concentration. Kevin Schug offers some insight about SPE basics and achieving successful extractions.

This blog attempts to provide an impartial guide to liner selection which is representative of the considerations in modern capillary GC.

Graduate students seeking doctoral degrees in chemistry require guidance and help in completing their dissertations. In the April installment of The LCGC Blog, Kevin Schug discusses this process and the efforts of four of his students.

Of late we have been running a series called 'Lock and Leave', which serves as a reminder to pay attention to those instrument parameters which are often overlooked - you know the type of thing ? 'that's the best value for this system?, 'we always set to that value' and 'I have no idea what that does' ? it's always at that value'.

The United States woefully underfunds international collaborations with the Czech Republic. Yet, it is a country that produces excellent scientists who are distinctly passionate about science, and who have been educated to demonstrate not only a strong mastery of chemistry basics, but also superb knowledge of the integration of high-level mathematics and computer programming skills into their science. One need not look very far in the separation science and mass spectrometry (MS) fields in the United States to find eminent leaders with roots in the Czech Republic.

Surrogates, Internal Standards, Isotopically labelled Standards, External Standards, Calibrants, QC Samples etc. etc. - our working lives are littered with checks to ensure that our instruments are giving us the correct results. And rightly so. But do we always use these checks correctly? Do we know what we are checking and why? Indeed, do we know how to design methods/procedures which employ a valid checking regime, often referred to as a Quality System? Let's find out.

Analytical chemists entering the work force are not always ready to face the challenges of private industry. Kevin Schug discusses how best to prepare students for the next stage of their careers.

An assembly of thoughts on all things filtration for HPLC - and how to deal with various nasties - from Rocks to Sand.

There has been much focus within the industry of late on ways of improving the way in which HPLC method development is carried out - which has led to a more widespread adoption of modelling and optimisation software combined with dedicated method development platforms from the major instrument vendors.

Flow injection analysis (FIA) is a powerful technique for quantitative analysis, especially in conjunction with mass spectrometry (MS) detection. Kevin Schug discusses how FIA can be combined with MS using electrospray ionization and describes how the technique can be used for analytes such as binding constant determination, multipoint instrument response calibrations, and removing the dependence of measured analyze concentrations on matrix effects.

No, this isn't a new detective novel, in fact its two concepts which were "coined" by my good friend John Hinshaw during a recent CHROMacademy webcast which we presented together on sample introduction for capillary GC.

Choosing the correct column for an application really requires that we consider the many factors which can influence the efficiency and selectivity of a separation including column hardware, support and surface chemistry. On a rainy day a little while ago our technical support group came up with a list of 23 such factors which need to be considered.

What would you do if faced with a zombie invasion in your analytical laboratory? LCGC Blog editor Kevin Schug provides guidelines and suggestions for fending off an attack, including how to use glassware and dead chromatography columns as defensive weapons and novel applications for laboratory lasers.

Tony Taylor provides insight on the best way to choose GC columns based on analyte or sample characteristics.

Researchers coupling high performance liquid chromatography to mass spectrometry face the challenge of segregating the ionized, typically nonvolatile analytes from a large amount of solvent, and the mobile phase is an important component in the process. LCGC Blog editor Kevin Schug discusses factors to consider when choosing a mobile phase for LC-MS.

Chromatography can be approximated by a series of equilibrium events between the mobile phase and stationary phase. Here, LCGC Blog editor Kevin Schug discusses an exceptional spreadsheet macro written by an undergraduate researcher that helps users visualize the development of chromatographic separations.

Chromatography can be approximated by a series of equilibrium events between the mobile phase and stationary phase. Here, LCGC Blog editor Kevin Schug discusses an exceptional spreadsheet macro written by an undergraduate researcher that helps users visualize the development of chromatographic separations.

Split/splitless injectors typically vaporise a sample dissolved in a suitable organic solvent under increased temperature. The sample vapours are entrained into the carrier gas flow inside a "liner" or "sleeve" within the inlet and from there pass into the column or out of the inlet via "split" line / valve. Splitless injection is used to perform an "on-instrument" dilution and the relative amounts of sample which enter the column or discarded to waste via the split line are adjusted using the relative carrier and split flow rate ratio.

J. Calvin Giddings provided one of the most practical discussions of the advantages of temperature programming in GC over isothermal analysis back in 1962. Here, Kevin Schug describes some of the salient points of that discussion and how they still apply today.

This month we take a look at the important topic of buffer choice for HPLC separations, how to the choose the correct buffer type and concentration as well as how to avoid variability in retention and selectivity.

J. Calvin Giddings provided one of the most practical discussions of the advantages of temperature programming in GC over isothermal analysis back in 1962. Here, Kevin Schug describes some of the salient points of that discussion and how they still apply today.

This month we take a look at the important topic of buffer choice for HPLC separations, how to the choose the correct buffer type and concentration as well as how to avoid variability in retention and selectivity.

It's important for chromatographers (particularly those who are also graduate students) to understand the fundamental aspects of separation science. In this installment of the LCGC Blog, Kevin Schug discusses the connection between thermodynamics and chromatography.

The nature of retention time changes in HPLC tends to fall into categories. Firstly, the retention time may "drift" over several injections or several analytical campaigns and secondly, the retention time may suddenly "jump to a different value between injections or between analytical campaigns (i.e. analyte retention times are very different to when that method was run last).

The physical characteristics of silica-based HPLC columns can affect the performance of the separation almost as much as the bonded phase. This month's technical tip re-visits some of the lesser known or remembered facts relating to silica particles used for chromatography.

This month we'll have a look at some tips and tricks on how to tighten up the robustness of our gradient methods and offer some quick calculations to check we're getting it right!

Kevin Schug discusses the power of MS for resolving an enormous number of compounds in a sample.

The physical characteristics of silica-based HPLC columns can affect the performance of the separation almost as much as the bonded phase. This month's technical tip re-visits some of the lesser known or remembered facts relating to silica particles used for chromatography.

Oceanographers have extremely challenging analysis problems to overcome. Can analytical chemists help? The Collaborative on Oceanographic Chemical Analysis workshop, sponsored by the National Science Foundation, connects scientists in these two fields to exchange ideas. And that is good, because the needs are great. Kevin Schug takes a look at where that collaboration might lead.

A number of retention time issues can cause problems in HPLC. Here's advice on how to handle common ones, such as retention time drift, temperature variability, problems arising from column equilibration, and difficulties validating a method.

Method validation is a concept that has been ingrained (or should have been ingrained) in the minds of most analytical chemists. Any new method that is created has to be proven reliable and provide some level of performance under well-defined conditions.

The LCGC Blog

Should HPLC eluent additives be added to one or both of the constituent mobile phase reservoirs - both organic and aqueous, when mixing gradients online?

The Technical Department at Crawford Scientific are regularly asked for analytical conditions or applications in the hydrophilic interaction liquid chromatography (HILIC) mode. Here?s a short primer on what you need to understand about this separation mode from a practical perspective, using some of the questions that we regularly get asked.

Derivatization of the analytes targeted in an HPLC-ESI-MS separation can help improve detection limits.

In this months technical tip we answer some often asked questions and dispel some myths regarding HPLC column abuse and reconditioning

In this months technical tip we answer some often asked questions and dispel some myths regarding HPLC column abuse and reconditioning

Restricted-access media (RAM) offer many advantages and can make it easier to achieve efficient and reproducible on-line sample preparation. In spite of this, these media have been underutilized. It is time for more research into RAM.

A review highlighting the recent development on flow-injection analysis (FIA)–mass spectrometry (MS) to bring more attention to this effort.