R Kapeller
Austrian Agency for Health and Food Safety, Austria
Title: Retention time correction in gas chromatography by modelling concentration related effects
Biography
Biography: R Kapeller
Abstract
Highly reproducible retention times (tR) are a basic requirement for automation of peak assignment in complex gas chromatograms. Drifting retention times are handled best by frequent updates, based on reference peaks, even for every chromatogram, if a sufficient number of reference peaks is always present. The updates may be interpolated for peaks between the reference peaks. Some refinements of this concept have been reported as well as alternative concepts, including pattern recognition algorithms to achieve ultimate precision.
However, there are applications causing additional challenges requiring special measures. One is the effect of concentration on tR of individual peaks, becoming relevant, where - in addition to high complexity and variability in composition - a wide concentration range has to be covered. The analysis of fatty acid methyl esters (FAME) is such an application. A model describing concentration related effects on tR was drawn up and found to work best for this purpose. The precision of peak alignment could be improved by more than an order of magnitude, allowing reliable automation of routine analysis.