Capillary electrochromatography-applicability to the analysis of pesticides and compounds of environmental concern and the theory of electroosmosis

Summary The applicability of capillary electrochromatography to the automated analysis of pesticides and phthalate esters that are of environmental concern was assessed. Reversed phase packing materials were compared. Column to column and run to run reproducibility was established. Peak height with an internal standard gave the best reproducibility. Faster analysis than alternative HPLC methods was demonstrated for a mixture of the insecticide pirimicarb and related pyrimidines. The relationship between the concentration of an analyte in a sample and at the detector was determined by the use of radio-labelled¹⁴C-pirimicarb. The volume fraction of the liquid zone was 0.64. The possibility of electroosmosis through the pores is discussed with reference to the Rice-Whitehead model for electroosmotic flow in a capillary. A new parameter, the effective pore size is used in equations for electroosmosis through porous packings.