A Novel Combination of Liquid Chromatography and Electron Capture Detection in the Analysis of Pesticides

Abstract

A novel combination of LC and electron capture detector (ECD) is described in which the connection between the column and the detector avoids the use of a complex phase transport system (e.g. moving wire) and does not introduce any significant loss in column resolution. Direct comparison has been made between a variable wavelength UV absorption detector and the ECD with particular reference to the analysis of organochlorine pesticides, polychlorinated biphenyls, etc. Operation of the ECD in both the conventional pulse mode and the newer constant current mode has shown that its sensitivity toward organochlorine pesticides is about two orders greater than that of the UV absorption detector, enabling −10 g of aldrin to be detected. The linear working range in the constant current mode is ∼ 500, but appreciably less than this in the pulse mode. The advantages of this detector are illustrated by applications related to the analysis of pesticides in environmental samples.