LCGC North America-01-01-2011

New methods are available for whole blood analysis. Here, various approaches are compared and contrasted.

When good things are given to us, or when we have never known life without them, we rarely appreciate them fully. This truth applies to many areas of life, but tends to be particularly evident with respect to modern conveniences and technological advances. Anyone with a teenager who thinks having a cell phone or an iPod is a requirement, not a luxury, knows this; pointing out that every generation until this one grew up without such devices rarely elicits more than eye rolling. Young people are not the only ones who take things for granted, however. When was the last time most of us truly felt grateful for our flush toilets or hot showers? Probably shortly after a camping trip or when the water heater broke.

This article describes the operating principles of the direct-electron ionization (EI) interface, which is becoming more popular in many LC–MS applications. Matrix effects and the role of direct-EI as a universal detector for small molecule analysis are also discussed in detail. The advantages and drawbacks of this approach are described and a comparison with atmospheric pressure ionization (API) interfaces is made. The potential of direct-EI is illustrated with a selection of practical applications.

This article demonstrates the superiority of the GC-MS approach over spectrophotometry.

The authors discuss an LC method for the direct analysis of diquat and paraquat in lake water.

The authors discuss the specifics of analytical method validation.

This article illustrates how to choose the best experimental parameters for asymmetrical flow field-flow fractionation.

A change in the mobile phase strength can be a powerful tool to move peaks in a separation.

John Hinshaw investigates the influence that choosing hydrogen carrier has on column selection and operation with direct-interface GC?MS.

Click the title above to open the LCGC North America January 2011 regular issue, Vol 29 No 1, in an interactive PDF format.