采用三因素三水平响应面分析法对尿液中甲基苯丙胺(MPM)的固相萃取(SPE)条件作优化试验,所得最佳SPE条件为:① 尿样的酸度:pH 9.35(PBS);② 上样速率:0.9 mL·min-1;③ 洗脱剂(乙酸乙酯)的用量:3.2 mL。所得淋出液氮吹蒸干,溶于100 μL内标物(SKF525-A)乙醇溶液中,供气相色谱分析。用AB-5毛细管色谱柱分离,进样量为1 μL。采用氮磷检测器进行测定。甲基苯丙胺的质量浓度与其峰面积在0.10~10.0 mg·L-1范围内呈线性关系,检出限(3S/N)为0.062 mg·L-1。日内和日间相对标准偏差(n=6)均小于5%。

Response surface analysis with 3 factors and at 3 levels was applied to the optimization of conditions of solid phase extraction (SPE) of methamphetamine (MPM) in human urine, and the optimum conditions found were as follows: ① acidity of the urine sample: pH 9.35 (PBS); ② flow-rate of sample introduction: 0.9 mL·min-1; ③ appropriate volume of ethyl acetate as eluant: 3.2 mL. The eluate obtained was evaporated to dryness by N2-blowing, and the residue was taken up with 100 μL of ethanol solution of the internal standard of SKF525-A, and the solution was used for GC analysis. Chromatographic separation was carried out on AB-5 capillary column with volume of sample introduction of 1 μL. Nitrogen-phosphorus detector was used in the determination. Linear relationship between values of peak area and mass concentration of methamphetamine was kept in the range of 0.10-10.0 mg·L-1 with detection limit (3S/N) of 0.062 mg·L-1. Values of within-day and inter-day RSD′s (n=6) obtained were same to be less than 5%.