[Studies on quantitative analysis of paraquat in whole blood--the evaluation of pre-treatments and analytical methods]

Paraquat and diquat are bipyridylium herbicide, which fatal poisoning cases have been reported in recent years. There are a number of methods for the pre-treatment and analysis of paraquat in body fluids and postmortem tissues. But the combined evaluation of these pre-treatments and analytical methods can be hardly found in literatures. We have carried out quantification of paraquat in whole blood with various combinations of pre-treatments and analytical methods, and evaluated those with respect to the sensitivity, recovery, time and cost. Non-treatment sample was a diluted solution of whole blood containing an aliquot of paraquat. The pre-treatments were achieved using two sorts of protein precipitants or Sep-Pak C18 cartridge. HPLC, second-derivative spectroscopy and ELISA were selected as analytical methods for quantification of paraquat. The most sensitive methods were combination of protein precipitants or Sep-Pak C18 and ELISA, but a combination of protein precipitant of sulfosalicylic acid and second-derivative spectroscopy was found to be more rapid and economical method. These methods would be applicable in forensic and clinical laboratories.