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目的建立甲酯衍生化液液萃取-气相色谱法测定尿液中三氯乙酸的方法。方法在浓H_2SO_4催化下,尿液中的三氯乙酸与甲醇发生酯化反应,酯化产物通过正己烷液液萃取,离心,吸取有机相经无水硫酸钠干燥后注入气相色谱仪,经HP-INNOWAX毛细管色谱柱(30 m×0.32 mm,0.15μm)分离,采用氢火焰离子化检测器(FID)检测,以保留时间定性,峰面积定量。结果三氯乙酸在5.0 mg/L~500.0 mg/L呈线性关系,相关系数为0.999 6,以3倍噪音值估算方法的检出限为1.2 mg/L。在浓度为10.0 mg/L~400.0 mg/L低、中、高3个添加水平下,样品的加标回收率为95.2%~98.8%;批内精密度为1.24%~2.69%(n=6),批间精密度为1.52%~2.22%(n=6)。结论本法简单实用,重现性好,灵敏度高,可以满足尿样中三氯乙酸检测的要求。
Objective To establish a method for the determination of trichloroacetic acid in urine by methyl ester derivatization with liquid-liquid extraction and gas chromatography. Methods Esterification of trichloroacetic acid with methanol in concentrated H_2SO_4 was carried out. The esterified product was extracted by n-hexane liquid-liquid extraction and centrifuged. The organic phase was extracted with anhydrous sodium sulfate and injected into the gas chromatograph. -INNOWAX capillary column (30 m × 0.32 mm, 0.15 μm), and detected by hydrogen flame ionization detector (FID). The retention time was qualitative and the peak area was quantified. Results The concentration of trichloroacetic acid was linear in the range of 5.0 mg / L to 500.0 mg / L with a correlation coefficient of 0.999 6. The detection limit of trichloroacetic acid was 1.2 mg / L. The recoveries of spiked samples ranged from 95.2% to 98.8% at the low, medium and high levels of 10.0 mg / L to 400.0 mg / L. The intra-assay precision ranged from 1.24% to 2.69% (n = 6 ), The inter-batch precision was 1.52% ~ 2.22% (n = 6). Conclusion This method is simple and practical, reproducible, high sensitivity and can meet the requirements of trichloroacetic acid in urine samples.