High-performance liquid chromatographic assay of phosphate and organophosphorus pesticides using a post-column photochemical reaction and fluorimetric detection

Pesticide residues below ng ml−1 levels could be determined in environmental waters when a preconcentration device was coupled on-line with the HPLC system. Detection limits as low as 0.01 ng ml−1 were achieved for only 250 ml of sample. In the analyses of vegetables and grains, the detection limit was about 1 μg kg−1.