气相色谱-质谱同时测定猪肉中3种巴比妥药物残留

Simultaneous Determination of Three Barbiturates in Pork by Gas Chromatography-Mass Spectrometry

建立了固相萃取气相色谱-质谱同时分析猪肉中3种巴比妥类药物残留量的方法。对猪肉样品的乙腈提取、C18固相萃取柱净化和碘甲烷甲基化条件进行了优化。采用HP5毛细管柱分离,电子轰击电离源质谱选择离子模式(SIM)检测(巴比妥m/z126,169,183,184;异戊巴比妥m/z169、170、184、226;苯巴比妥m/z175、232、245、260;dwelltime80s),外标法定量(定量离子m/z分别为169、169和232)。3种巴比妥药物的添加标准曲线线性回归系数均在0.99以上;线性范围2.5～50μg/kg,回收率为65%～112%,相对标准偏差5.4%～17.2%,检出限均为1μg/kg。

Solid phase extraction (SPE) and gas chromatography-mass spectrometric method have been developed for the determination of barbital, amobarbital and phenobarbital residues in pork. The conditions for extraction, clean-up on C-18 column and methylation with CH3I of barbiturates were investigated and optimized. The methylized analytes were separated by HP-5 chromatographic column, detected by mass detector in electron impact and time program-selected ion manitoring mode ( EI/MIS) and quantified with the external standard calibration curve method. Good linear correlations have been obtained between the peak areas and spiked concentrations of the three barbiturates ( the calibration coefficients were above 0.99). The linear range was 2.5 similar to 50 mu g/kg. The average recoveries of the three barbiturates spiked in pork ranged from 65% to 112% and their relative standard deviations were between 5.4% and 17.2%. The limit of detection was 1 mu g/kg for the all three barbiturates.