Determination of the Oxime, 2-Hydroxyiminomethyl-3-Methyl-1-(2-(3- Methyl-3-Nitrobutyloxymethyl) Imidazolium Chloride in Plasma by HPLC

Abstract : An assay for the quantitation of the oxime, 2-Hydroxyiminomethyl-3- Methyl-1-2-(3-Methyl-3-Nitrobutyloxymethyl) Imidazolium Chloride, WR 255,737;CD 467, in plasma using high performance liquid chromatography is described. The above oxime (WR 255,737) was extracted from plasma by an ion-pairing liquid/ liquid method, and analyzed by normal phase HPLC and UV detection. After the addition of the internal standard, 1-(1-(3-Butynyloymethyl)-2- hydroxyiminomethyl-3-methyl imidazolium chloride (WR 254,416), the sample was extracted into methylene chloride and subsequently back-extracted into a solution of 0.001M tetrabutylammonium hydrogen sulfate. Flow rate was 1.2 ml/min and the retention times were 2.1 min for WR 254,416 and 2.9 min for WR 255,737. Accuracy was evaluated from the analysis of blind, spiked samples which gave a coefficient of variation of < or = 2.6. The recovery was greater than 84%; interday variability was less than 7.8%; intraday variability was less than 3. 3%. Stability was determined for WR 255,737 in plasma at -15C and -80C. There was no degradation at either temperature for 23 weeks. Keywords: Antidotes, Organophosphates, Poisoning, Toxicity.