Dwight R. Stoll

When considering different ways to improve an established LC method, it helps to start by reviewing some essential concepts.

Developing a short list of the likely causes of these results can help streamline our troubleshooting experience when sensitivity-related problems occur.

Estimating expected peak widths helps us determine when a column and LC system is not performing optimally.

Knowing the tips and tricks of producing quality LC–MS data for peptide analysis can help streamline troubleshooting when problems occur.

This review article summarizes the results obtained from the combined efforts of a joint academic and industrial initiative to solve the real-life challenge of determining low levels of peptide-related impurities in the presence of the related biologically-active peptide at a high concentration.

Knowing the tips and tricks of producing quality LC–MS data for peptide analysis can help streamline troubleshooting when problems occur.

There are various physical and chemical causes of low detection sensitivity. Here, we address some of these causes, and how to troubleshoot them.

Some liquid chromatography (LC) troubleshooting topics never get old because there are some problems that persist in the practice of LC, even as instrument technology improves over time. There are many ways for things to go wrong in an LC system that ultimately manifest as detector baselines that do not look right. Developing a short list of the likely causes of these results can help streamline our troubleshooting experience when baseline-related problems occur.

When esterification occurs in your LC mobile phase, knowing how baseline quality, retention, and selectivity are affected will help you mitigate the effects.

A critical step in any troubleshooting exercise—but one that I think is underappreciated—is recognizing that there is a problem to be solved.

Knowing the likely causes of baseline-related problems will help you solve them.

As 2D-LC becomes used more widely and in regulated laboratory environments, development and implementation of SSTs will be critical for successful routine use of the 2D-LC technique.

In this article, I share my perspective on the trends in 2D-LC, and the developments we are likely to see in the field in the near future.

As two-dimensional liquid chromatography (2D-LC) becomes more widely used, system suitability tests (SSTs) become even more important.

We explain several of the more frequent causes of bad peak shapes in liquid chromatography and provide tips on how to remedy them.

There are some problems with LC separations that will probably never go away, such as shifting retention times.

Developing a short list of likely causes of retention-time problems in reversed-phase LC makes troubleshooting easier.

The impact of extracolumn dispersion on kinetic plot curves is investigated. A web-based calculator that allows users to make their own kinetic plots with examples of how the tool can be used to troubleshoot underperforming columns and support column selection is discussed.

If we are going to achieve widespread adoption of multidimensional separations, we need more systematic approaches to method development that rely less on user experience.

A kinetic plot is a powerful tool, but how do you construct one—from either experimental data or data from other sources? We explain.

With kinetic plots, you can make better-informed column choices. Here’s how.

Kinetic plots can help us understand how different combinations of parameters will perform in relation the time needed to acquire a particular column efficiency—and thus resolution.

A kinetic plot is a powerful tool, but how do you construct one—from either experimental data or data from other sources? We explain.

The 13th Multidimensional Chromatography Workshop is a free virtual event involving keynote presentations, contributed presentations, and discussion groups, and is happening virtually on 31 January–2 February 2022.

Some “LC Troubleshooting” topics never get old because there are some problems that persist in the practice of LC, even as instrument technology improves over time.

Kinetic plots can help us understand how different combinations of parameters will perform in relation the time needed to acquire a particular column efficiency—and thus resolution.

In this third part in the series, we discuss chemical causes of peak asymmetry, including effects from mass overload and slow desorption kinetics.

The 13th Multidimensional Chromatography Workshop is a free event involving keynote presentations, contributed presentations, and discussion groups on all multi-dimensional techniques happening virtually on January 31, 2022 - February 2, 2022.

Deviations from the expected pressure in modern LC systems (too low, too high, or fluctuating) can be diagnosed and more quickly resolved using the streamlined troubleshooting practices shown here.

In this instalment, we focus on the impact of elution mode (isocratic or gradient) and postcolumn flow splitting on the total level of extracolumn dispersion (ECD) in a liquid chromatography (LC) system, and demonstrate the use of a free, web-based calculator that can be used to guide decision making aimed at reducing ECD during method development.