Analytical method for screening and quantification of phosphated amino acid herbicides in the serum of acutely intoxicated patients using HPLC with a diode-array-detector

An analytical method was established for the screening and quantification of phosphated amino acid herbicides (PAAHs), such as glyphosate, glufosinate and bialaphos, which frequently cause intoxication. The procedure involves the extraction of PAAHs by Ultra-Free 4 from serum, derivatization of the filtrate using p-toluensulfonyl chloride, and then HPLC analysis of the resulting p-toluensulfonyl derivatives. They can be identified by their UV spectra and retention times by comparison with authentic samples. The detection limits were less than 10 ng, which is sufficient for determining pesticides in serum. The overall recovery from serum was almost the same for each herbicide. The calibration curves were linear over a wide range. The sera of three acutely poisoned patients who took one of the above three PAAHs were examined by this method, and the results were shown to be accurate and sensitive. The analysis required only 1 h. The present method is useful not only for screening but also for quantitative analysis of pesticides causing acute intoxication. Their early identification may help prevent death.