摘要：The analytical procedure and detectable period of a muscular relaxant, suxamethonium, in postmortem rat tissues were studied. Rats were killed by intraperitoneal administration of suxamethonium at doses of 10 mg/kg body weight. The dead rats were stored at room temperature (25°C) and in refrigerator (0°C) until the time of the analysis. Suxamethonium in the tissues was identified and quantitated using Frit-FAB LC-MS following the solid phase extraction with a Bond Elut CBA cartridge. The rat tissue was homogenized and deproteinized with perchloric acid. The resulting supernatant was applied to the cartridge. Suxamethonium adsorbed on the cartridge was eluted with 1 ml of 0.1 M hydrochloride-methanol (1 : 1, v/v). Hexamethonium solution was added to the eluate as an internal standard. An aliquot (1 μl) of the eluate was injected into the Frit-FAB LC-MS system. The LC column used was a capillary-type Develosil ODS-UG-5 (0.3 mm i.d.×150 mm). The gradient mobile phase system was composed of eluent A (0.1% trifluoroacetic acid, including 0.4% glycerol) and eluent B (methanol, including 0.4% glycerol), and the concentration of eluent B increased from 0% to 30% over 20 min. The flow rate was 5 μl/min. The mass spectrum of suxamethonium gave the adduct of a molecular ion with trifluoroacetic acid (m/z 403) as a base peak. The detection limit of suxamethonium in the tissue by selected ion monitoring (SIM) was 5 ng/g. Suxamethonium in rats stored at 25°C and 0°C after death were found to be detectable for 7 and 42 d in the liver, 7 and 42 d in the kidney, and 2 and 4 d in the heart, respectively.
关键词：suxamethonium;LC-MS;Frit-FAB;rat tissue;detectable period
