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目的建立分散液-液微萃取-气相色谱法测定尿液中三氯乙酸的方法。方法在浓H2SO4催化下,尿中三氯乙酸与甲醇发生酯化反应,生成三氯乙酸甲酯,三氯乙酸甲酯通过分散液-液微萃取(DLLME),离心后吸取下层有机相注入气相色谱仪,经DB-FFAP毛细管色谱柱(30 m×0.32 mm,0.50μm)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。结果本法三氯乙酸在5.0 mg/L~200.0 mg/L浓度时呈线性,相关系数为0.999 1,以3倍噪音值估算方法检出限为2.6 mg/L。在10.0 mg/L~200.0 mg/L时添加低、中、高3个浓度水平,样品加标回收率为92.0%~96.5%;批内精密度为2.21%~3.22%(n=6),批间精密度为2.10%~4.29%(n=6);对20份尿样同时采用本法和国家标准方法 WS/T 64—1996测定,2种方法检测结果差异无统计学意义(P>0.05)。结论本法简单实用,有机试剂用量少,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 dispersive liquid-liquid microextraction-gas chromatography. Methods The esterification of trichloroacetic acid with methanol in the presence of H2SO4 catalyzed the esterification of trichloroacetic acid with methanol to produce methyl trichloroacetate. The trichloroacetic acid methyl ester was separated by liquid-liquid microextraction (DLLME) The chromatograph was separated on a DB-FFAP capillary column (30 m × 0.32 mm, 0.50 μm) and detected by hydrogen flame ionization detector (FID). The retention time was qualitative and the peak area was quantified. Results The trichloroacetic acid showed a linearity of 5.0 mg / L ~ 200.0 mg / L with a correlation coefficient of 0.999 1. The detection limit of triple trichloroacetic acid was 2.6 mg / L. The recoveries of spiked samples ranged from 92.0% to 96.5% at the low, medium and high levels of 10.0 mg / L to 200.0 mg / L. The intra-assay precision ranged from 2.21% to 3.22% (n = 6) The inter-batch precision was 2.10% ~ 4.29% (n = 6). There was no significant difference between the two methods in the detection of 20 urine samples by this method and the national standard method WS / T 64-1996 (P> 0.05). Conclusion This method is simple and practical, with less organic reagents and high sensitivity, which can meet the requirements of trichloroacetic acid detection in urine samples.