Rapid and Sensitive Analysis of Diclofenac in Human Plasma by GC/SIM/MS

ABSTRACT

An analytical method for the determination of diclofenac with tolfenamic acid as the internal standard was developed and validated in human plasma by capillary gas chromatography-mass spectrometry (GC/MS). After the addition of the internal standard, the compounds were extracted from plasma at acidic pH into diethylether, which was then evaporated to dryness. The compounds were derivatized with pentafluoropropionic anhydride (PFPA) and a mixture (1000:2:3, v/w/w) of N-methyl-N-trimethylsilyltrifluoroacetamide (MSTFA), ammonium iodide (NH₄I), and dithioerythritol (DTE). They were determined by GC/MS at m/z 349 (a molecular ion) for diclofenac and m/z 270 (a base ion) for tolfenamic acid. The recovery of this procedure was 97.8%, and the linearity for calibration was 0.9907 as the coefficient factor. The detection and quantitation limits were 0.1 and 0.5 ng/mL, respectively.     

气相色谱-质谱联用法测定蜂蜜中丙三醇的三甲基硅烷化衍生物

蜂蜜样品用二甲基甲酰胺溶液解后,直接用N,O-双(三甲基硅烷基)三氟乙酰胺衍生,所生成的三甲基硅烷衍生物用色谱-质谱法测定。本法与酶分析法进行了比较,两者之间无显著性差异。方法的线性范围为20～2000mg／kg,检出限为10mg／kg,相对标准偏差为0．4％～1．4％,标准加入回收率为98．8％～102．4％。采用本方法检测了316份蜂密的丙三醇含量,方法具有快速、准确的特点。