Electrochemical Detection of Phenylurea Herbicides in Liquid Chromatography

Abstract
The electrochemical detection of 10 phenylurea herbicides after on-line trace enrichment on a small C18 precolumn and liquid chromatography on a C18 analytical column is described. The method presented shows sub-ppb sensitivity in surface water samples without extensive sample pretreatment. Electrode contamination occurs but does not seriously interfere in the routine analysis of such samples. Selective determination (at 1.0 V) of metoxuron in the presence of other phenylureas allows the detection of 30 ppt of the herbicide in surface water.