AUTOMATED SOLID-PHASE EXTRACTION OF HERBICIDES FROM WATER FOR GAS-CHROMATOGRAPHIC MASS-SPECTROMETRIC ANALYSIS

An automated solid-phase extraction (SPE) method was developed for the pre-concentration of chloroacetanilide and triazine herbicides, and two triazine metabolites from 100-ml water samples. Breakthrough experiments for the C18 SPE cartridge show that the two triazine metabolites are not fully retained and that increasing flow-rate decreases their retention. Standard curve r2 values of 0.998-1.000 for each compound were consistently obtained and a quantitation level of 0.05 mug/l was achieved for each compound tested. More than 10 000 surface and ground water samples have been analyzed by this method.