October 29th 2024
Manitoba Centre for Proteomics and Systems Biology scientists produced a new means of predicting peptide retention times for hydrophilic interaction liquid chromatography (HILIC) at acidic pH in formic-acid based eluents.
Resources for LC Practitioners in 2017: What’s on Your Bookshelf and in Your Web Browser?
December 1st 2017What are the most useful chromatography books on your bookshelf? What are the most useful web-based resources (such as websites, downloadable documents, videos) about separation science? What are the most useful tools supporting your work (such as calculators and simulators)? In this installment, Dwight Stoll compiles input from the separation science community (both individuals and vendors) to guide you to the resources that people find most useful.
The Recent Advances in Comprehensive Chromatographic Analysis of Emerging Drugs
December 1st 2017To address the challenges of analyzing new illicit drugs, emerging techniques such as UHPSFC with MS and UV detection, and GC with VUV detection, may be needed, particularly for distinguishing positional isomers and diastereomers.
Characterizing Red Chicory Polyphenols
November 7th 2017Polyphenols are a well-known group of antioxidants widely diffused as secondary metabolites in plants, vegetables, and fruit. The Column spoke to Nicola Marchetti from the Department of Chemistry and Pharmaceutical Sciences at the University of Ferrara in Ferrara, Italy, about his research into the characterization of polyphenols in red chicory using high performance liquid chromatography–tandem mass spectrometry (HPLC–MS/MS).
Equivalent Column Selection in HPLC
November 7th 2017High performance liquid chromatography (HPLC) methods are used today to control the quality of many chemical and pharmaceutical products. The methods are usually developed by optimizing the properties of the mobile phase with a specific column. However, if the original column is no longer in production, the result will often change when a different column is used. In this case, we were interested in finding one or two equivalent columns that can replace the original column without changes in selectivity and robustness. This study demonstrates a new way to compare columns and select suitable replacement columns. The presented method will also allow the evaluation of different columns with the same method, as well as the evaluation of the robustness of the common method with different columns.
LC Column Technology: The State of the Art
November 1st 2017In this extended special feature to celebrate the 30th anniversary edition of LCGC Europe, leading figures from the separation science community explore contemporary trends in separation science and identify possible future developments. We asked key opinion leaders in the field to discuss the current state of the art in liquid chromatography column technology, gas chromatography, sample preparation, and liquid chromatography instruments. They also describe the latest practical developments in supercritical fluid chromatography, 3D printing, capillary electrophoresis, data handling, comprehensive two‑dimensional liquid chromatography, and multidimensional gas chromatography.
LC Instrumentation: The State of the Art
November 1st 2017In this extended special feature to celebrate the 30th anniversary edition of LCGC Europe, leading figures from the separation science community explore contemporary trends in separation science and identify possible future developments. We asked key opinion leaders in the field to discuss the current state of the art in liquid chromatography instruments.
34 Years of LC Troubleshooting: An Interview with John Dolan
October 1st 2017Dwight Stoll, who will take the reins of “LC Troubleshooting” next month, spoke with John Dolan to get some insight on the current state of chromatography with John Dolan to get some insight on the current state of chromatography training, future troubleshooting problems, John’s toughest troubleshooting challenge, and the most common chromatographic mistakes.
Column Care for the Long Haul—Considerations for Column Storage
July 1st 2017Several factors influence the useful lifetime of high performance liquid chromatography (HPLC) columns. In this instalment we consider some of the details associated with preparing a column for storage, with an eye towards choices that will pay dividends in future use of the column.
New Advice on an Old Topic: Buffers in Reversed-Phase HPLC
July 1st 2017Buffers are commonly used in reversed-phase liquid chromatography (LC) to control the ionization state of analytes. However, the addition of buffers is much more complex than simple pH control. Complex equilibria exist between these mobile-phase additives, the analytes, the silica surface, and even the stationary phase in certain circumstances. The addition of mass spectrometry (MS) as a primary detection technique makes decisions about mobile-phase additives even more crucial. In this column instalment, we use a model set of analytes and selected applications to demonstrate the effects that buffers can have not only on the selectivity of a separation, but also on the sensitivity of a reversed-phase analysis when using MS detection.
Comparing the Separation Speed of Contemporary LC, SFC, and GC
June 1st 2017Some 50 years after Giddings’s iconic comparison of the separation speed of gas chromatography (GC) and liquid chromatography (LC), the authors revisit this comparison using kinetic plots of the current state‑of‑the-art systems in LC, supercritical fluid chromatography (SFC), and GC. It is found that, despite the major progress LC has made in the past decade (sub-2-µm particles, pressures up to 1500 bar, core–shell particles), a fully optimized ultrahigh-pressure liquid chromatography (UHPLC) separation is still at least one order of magnitude slower than capillary GC. The speed limits of packed bed SFC are situated in between.
UHPLC, Part 1: Perspectives and Instrumental Features
June 1st 2017This instalment highlights historical perspectives on the development of ultrahigh-pressure liquid chromatography (UHPLC) into a modern high performance liquid chromatography (HPLC) platform and describes the important instrumental features common to most commercial equipment.
Contemporary Trends in Biopharmaceutical Analysis
May 1st 2017The HPLC symposium series is recognized as “the forum” where new developments in liquid phase separations and their hyphenation to mass spectrometry (MS) for the analysis of (bio)pharmaceutical compounds and their metabolites are presented.
New HPLC Systems and Related Products: A Brief Review
April 1st 2017This instalment highlights new high performance liquid chromatography (HPLC) systems, modules, and software that were introduced at Pittcon 2017 and during the year prior, and describes their innovative features and significant benefits.
uHPLC Teaching Assistant: A New Tool for Learning and Teaching Liquid Chromatography, Part 1
January 18th 2017The free spreadsheet-based program HPLC Teaching Assistant was developed for effective and innovative learning and teaching of liquid chromatography. This software allows teachers to illustrate the basic principles of high performance liquid chromatography (HPLC) using virtual chromatograms (simulated chromatograms) obtained under various analytical conditions. In the first instalment of this series, we demonstrate the possibilities offered by this spreadsheet to illustrate the concept of chromatographic resolution, including the impact of retention, selectivity, and efficiency; understand the plate height (van Deemter) equation and kinetic performance in HPLC; recognize the importance of analyte lipophilicity (log P) on retention and selectivity in reversed-phase HPLC mode; and manipulate or adapt reversed-phase HPLC retention, taking into account the acido-basic properties (pKa) of compounds and the mobile-phase pH.