ENZYME-BASED MICROASSAY FOR ACCURATE DETERMINATION OF SOMAN IN BLOOD-SAMPLES

Successful medical therapy for nerve agent intoxication requires early diagnosis and treatment, Current clinical diagnostic methods do not p ermit, early or definitive confirmation of intoxication. To improve th e chances of successful medical therapy against nerve agent intoxicati on, a sensitive enzyme-based microassay for rapid and accurate quantif ication of residual soman levels in blood was developed. The new annal ytical technique is based on the linear correlation between residual e el acetylcholinesterase activities and the inhibitor concentration. Bl ood samples were deproteinized with perchloric acid, followed by immed iate neutralization after deproteinization. The mixtures were centrifu ged at 3000g and the supernatant was directly assayed for soman, The s ensitivity of the technique (1.8-1.820 pg/ml blood) is comparable to t hat attained by GC-FID analysis (250 pg/ml blood). To facilitate routi ne analysis, the linear range of the assay was optimized to span over a factor of 100 (0.1-10 nM), with a typical correlation factor of at l east 0.999 (six standards), The assay accuracy, checked with four diff erent concentrations of soman, was within +/-10%, The assay capability in monitoring the pharmacokinetic of soman was validated using both i n vitro and in vivo rat models. (C) 1998 Academic Press.