Quantitative analysis of the aminosteroidal non-depolarizing neuromuscular blocking agent vecuronium by LC-ESI-MS: A...

The apparent recreational use of an aminosteroidal non-depolarizing neuromuscular blocking agent, vecuronium, is reported in this postmortem investigation. A quantitative method for the analysis of vecuronium and its active metabolite, 3-desacetylvecuronium, in blood and tissue samples was developed using liquid chromatography-electrospray ionization mass spectrometry operated in positive selected ion monitoring mode. Chromatographic separation was performed on a Gemini 5-microm C18 column using a mobile phase of 0.1% formic acid/acetonitrile at 0.700 mL/min. The method was linear from 0.01 to 1.00 mg/L with correlation coefficients of 0.999 and greater for both compounds. The limits of detection and quantitation were determined in blood to be 0.005 and 0.010 mg/L, respectively. The coefficients of variation were less than 10% for both intra- and interday assays. Vecuronium was quantitated in blood at 0.070 mg/L and in the kidney, liver, and spleen at 0.224, 0.045, and 0.080 mg/kg, respectively. The active metabolite 3-desacetylvecuronium was quantitated in blood at 0.100 mg/L, in the urine at 0.040 mg/L and in the kidney, liver, spleen, and lung at 0.271, 0.100, 0.082, and 0.164 mg/kg, respectively.