Author


John W. Eschelbach

Latest:

Recent Advances in Ultrahigh-Pressure Liquid Chromatography

Ultrahigh-pressure liquid chromatography (UHPLC) is a technique that is experiencing continued growth due to the benefits in separation power and speed of analysis over traditional HPLC. We attempt here to give an overview of some of the advances that have occurred in UHPLC since 2003, from the standpoint of both fundamental research and the introduction of commercially-available technology.


Ray Chen

Latest:

Quantitative Analysis of Pseudoephedrine Tablets by UHPLC–MS

An effective UHPLC–MS method for high throughput separation, identification and quantification of pseudoephedrine was developed on a Hypersil GOLD PFP 1.9 µm, 2.1 Ã- 100 mm column.




Tianlan Zhang

Latest:

Comparison of Quadrupole, Time-of-Flight, and Fourier Transform Mass Analyzers for LC-MS Applications

The authors investigated the analytical capabilities of quadrupole, time-of-flight, and Fourier transform mass analyzers for liquid chromatography electrospray mass spectrometry (LC-MS) applications.


Zoe A. Grosser

Latest:

A Comparison of ICP-OES and ICP-MS for the Determination of Metals in Food

The determination of inorganic elements in food substances is critical for assessing nutritional composition and identifying food contamination sources. The inorganic elements of interest can be divided into two classes: nutritional and toxic. It is important to determine the levels of both sets of elements accurately to assess both the nutritional and the harmful impacts of food substances. Nutritional elements such as Mg, P, and Fe are present at high levels (milligrams per kilogram), while toxic elements such as Pb, Hg, and Cd should be present only at trace levels (nanograms or micrograms per kilogram).




Ern Dawes

Latest:

The Integration of Microextraction Packed Sorbent (MEPS) into Multidimensional Strategies

LC/GC approaches to analysis are attractive because they combine the selectivity of solid-phase sorbents in the first dimension with the separating power and peak capacity of capillary GC in the following dimensions.


Lukas Vaclavik

Latest:

Quantitative Analysis of PFAS in Milk, Infant Formula, and Related Ingredients Using LC–MS

This method for PFAS analysis in milk and infant formula is robust, reliable, and reproducible, with scope to expand the list of PFAS in the future.


Lee Marotta

Latest:

The Benefit of Headspace Trap Coupled with GC–MS for the Determination of Trace Levels of BTEX Compounds in Drinking Water

This article will focus on the development of an optimized gas chromatography–mass spectrometry (GC–MS) method that improves upon the current EPA and European detection limit requirements for BTEX compounds and meets all other criteria described in EPA Method 524.2 for the measurement of purgeable organic compounds in water by capillary column GC–MS.


Tanya Gamble

Latest:

Quantitation and Confirmation of the Pesticide Malathion in Fruit Samples using Multiple ReactionMonitoring and MS-MS-MS

LC–MS-MS instruments operating in Multiple Reaction Monitoring (MRM) are widely used for targeted quantitation on triple quadrupole and hybrid triple quadrupole linear ion trap (QTRAP® ) systems because of their well known selectivity and sensitivity. In MRM mode, the first quadrupole (Q1) filters a specific precursor ion; the collision cell (Q2) generates fragments (product ions) which are filtered in the third quadrupole (Q3). Although this double mass filtering greatly reduces noise there is always a chance that elevated background levels or matrix signals interfere with the targeted analyte.


Jean-Luc Veuthey

Latest:

Free Excel Software for Performing Virtual Liquid Chromatography

A new free simulator is available for students, educators, and trainers to teach and perform virtual HPLC experiments that are applicable to real HPLC instrumentation and method development.


Tiffany C. Wirth

Latest:

Rapid Sampling and Identification of Volatile and Semivolatile Organic Compounds by GC-TMS in Support of Decision Quality Data

As analytical chemist(s), the data collected from samples we test represent information. That information may be required to direct environmental clean-up operations, help insure worker safety, or guide decisions for an emergency response to a chemical incident.



Phil Taylor

Latest:

A Robust and Sensitive Method for Detecting Glyphosate and Other Polar Pesticides in Food and Water: Multiple Analytes in a Single Injection without Derivatization

A new high-throughput LC–MS/MS method meets the challenge of eliminating matrix effects for monitoring, with high specificity, polar organic pesticides such as glyphosate in food and water, while meeting targeted limits of detection.


Wolfgang Schwack

Latest:

Planar Chromatography — Back to the Future?

Planar chromatography celebrates its 70th birthday. The technique dates back to 1938 when, at the Pharmaceutical Institute in Kharkov, Ukraine, N.A. Izmailov and M.S. Shraiber first devized a circular thin-layer chromatogram,1 which was called spread layer or spot chromatography at the time.


Paul Wrezel

Latest:

Assay for ppm Levels of Azide in Drug Substances

The removal of azide as a potential impurity from a drug substance may be critical to its safety profile. The quantitation of this impurity is an important control parameter. This article describes a simple and practical assay for azide using chemical derivatization and HPLC. The method is shown to be suitable for the intended purpose on three example test materials. Potential issues for wider applications are discussed.


Veronika R. Meyer

Latest:

Sampling: The Ghost in Front of the Laboratory Door

Sampling can be the most demanding part of an analysis. Anybody in charge of sampling needs a good understanding of the composition of the material to be investigated, its heterogeneity (or homogeneity, in simple cases), and the chemical properties of the analytes. Sampling procedures must be described in detail. Detecting the bias of a sampling procedure can be difficult; this fact is trivial, but it must not be forgotten.



David Steiniger

Latest:

Multiresidue Pesticide Analysis in Onion by a Modified QuEChERS Extraction and Ion Trap GC–MSn Analysis

Most recently formulated pesticides are smaller in molecular weight and designed to break down rapidly in the environment.


Richard Calverley

Latest:

Removal of Endogenous Matrix Components Using EVOLUTE® CX Mixed-Mode Cation Exchange Solid Phase Extraction

Sample preparation is an essential technique to remove unwanted matrix components prior to LC–MS-MS analysis of drugs in biological fluids. Plasma matrix components whether endogenous (salts, proteins, and phospholipids) or exogenous (dosing vehicles, e.g. PEG 400), can interfere with compounds of interest leading to regions of ion suppression or enhancement. This can lead to inaccurate quantitation and have adverse effects on sensitivity. Mixed-mode SPE provides cleaner extracts as a result of rigorous interference wash steps, afforded by the dual retention mechanism of the sorbents.


Chiara Cordero

Latest:

Advances in Chromatography Using Artificial Intelligence and Machine Learning

Scientists from the University of Turin, Italy have learned how to combine their complementary competencies in analytical chemistry and big data analytics to achieve significant advances in food science and health.


Scott Merriman

Latest:

Removal of Endogenous Matrix Components Using EVOLUTE® CX Mixed-Mode Cation Exchange Solid Phase Extraction

Sample preparation is an essential technique to remove unwanted matrix components prior to LC–MS-MS analysis of drugs in biological fluids. Plasma matrix components whether endogenous (salts, proteins, and phospholipids) or exogenous (dosing vehicles, e.g. PEG 400), can interfere with compounds of interest leading to regions of ion suppression or enhancement. This can lead to inaccurate quantitation and have adverse effects on sensitivity. Mixed-mode SPE provides cleaner extracts as a result of rigorous interference wash steps, afforded by the dual retention mechanism of the sorbents.



Hillel Brandes

Latest:

Tips for Maximizing the Performance of Core-Shell Columns

A key advantage of core-shell columns is that their performance can rival that of the traditional fully porous particle columns, but at somewhat larger particle sizes and at significantly lower backpressures.


Barbara Sgorbini

Latest:

“Truly Natural”: Fully Automated Stir-Bar Sorptive Extraction with Enantioselective GC–MS Quantitation of Chiral Markers of Peach Aroma

A simple, automated, and fast method to quantify complex odorants in foods is described using stir-bar sorptive extraction (SBSE) combined with fast enantioselective GC–MS analysis. The total analytical method takes only 30 minutes and does not require any sample pretreatment.


Charles Durant

Latest:

A Hydrophilic Interaction Chromatography Method for the Purity Analysis of Cytosine

Cytosine (chemical name 4-amino-2-hydroxypyrimidine) is a pyrimidine derivative with a hetereocyclic aromatic ring and two substituents (amine and keto groups) attached and is a polar compound of significant biological and pharmaceutical interest. In response to the intended use of bulk cytosine as a raw material in pharmaceutical manufacturing, a method for the determination of the purity of cytosine was developed.


Horizon Technology, Inc.

Latest:

Tackle Method 625.1 with Superior Evaporation

See the advantage in optimizing your solvent evaporation for maximum accuracy and precision to comply with U.S. EPA Method 625.1


Koni Grob

Latest:

Kurt Grob — One of the Fathers of Capillary GC

In this month's installment, Kurt Grob's life and achievements are described by someone who knew him like few other people did: his son, Koni Grob.