Investigation of GC detectors performance and validation

Detectors in gas chromatographs are used in many different ways. The functions varies with the requirement of sensing the chemicals at trace levels to measuring quantitatively the relative amounts of compounds in ppb to sub ppb levels. The requirement of minimum detectable sensitivity for GC detectors and its actual estimation during the analysis helps in assessing the performance of detectors and a stable response of the GC system. The paper reports the study carried out with a GC system equipped with detectors like Flame Ionization Detector(FID) and Electron Capture Detector(ECD). Both packed and capillary column have been used for estimating the minimum detectability of detectors. The FID sensitivity obtained is 1.14 coulombs/g C. The FID could minimum detect 2.65 x 10(-12) gram carbon per sec and ECD could minimum detect pesticides (Lindane) less than 1 femtogram. Such a procedure is useful for all those engaged in analysis with GC or are in the process of procuring good reliable GC system.