HPLC and GC Articles

This is the fourth "LC Troubleshooting" column in a series looking at different aspects of the calibration process for liquid chromatography (LC) methods. We first (1) considered whether or not to force a calibration curve through the origin (x = 0, y = 0). The next stop (2) was a discussion of some techniques to determine the limits of detection and quantification.

The worldwide shortage of the popular solvent acetonitrile started in the early fall of 2008. Many laboratories were caught unaware of this pending shortage and did not address the problem quickly enough while others who sensed the problem stocked up on the available supply at the time.

John Knox: I got into chromatography along with my great friend Howard Purnell in 1953. We were both PhD students working under R.G.W. Norrish at Cambridge. I was studying hydrocarbon combustion and Howard was investigating hydrocarbon pyrolysis.

This is the third instalment in a series of "LC Troubleshooting" columns that focus on calibration curves used for liquid chromatography (LC) methods.

Evaporation or drying down is used widely in the cleanup of biological samples by liquid-liquid extraction (LLE), solid-phase extraction (SPE), or protein-precipitation methods. Though it is necessary in some cases, such as to change solvent and to concentrate an analyte, there are several problems associated with the evaporation procedure.

What impact can choice of solvent have on the separations obtained in CE?

The Pittsburgh Conference retains its place as the preeminent annual analytical sciences meeting in the U.S. This year's conference witnessed the withdrawal of a number of companies from the exhibition.

This is the third installment in a series of "LC Troubleshooting" columns that focus on calibration curves used for liquid chromatography (LC) methods. We started (1) by looking at the issue of whether or not to force a calibration curve through the origin (x = 0, y = 0).

The increase in the number of controls an analytical laboratory must make that has occurred over the last 15–20 years has induced a radical change in the approach to chemical analysis.

Experimental designs are used in method development and robustness testing and have been discussed in an earlier article.1 An experimental design is an experimental set-up that allows the simultaneous examination of a predefined number of factors in a predefined number of experiments. Method development is often divided into a screening and an optimization step.