Sensitive determination of barbiturates in biological matrix by capillary electrophoresis using online large-volume sample stacking

In China, some forensic cases are caused by barbiturates. Thus, the determination of trace level barbiturates in body fluid is important for the poisoning investigation. In this study, an online large-volume sample stacking (LVSS) with polarity switching in capillary electrophoresis (CE) was applied for the sensitive determination of barbiturates. This technique involves injecting a large volume of sample into a capillary and removing the sample matrix plug out of the capillary by reversing the polarity. Quantitation limit obtained was 0.048, 0.057, 0.039, and 0.015 μg/mL for secobarbital, amobarbital, barbital, and phenobarbital (signal-to-noise ratio = 9). By using LVSS, the stacking was simply achieved at 171.7-, 169.7-, 202.7-, and 169.1-fold for the above four barbiturates. The relative standard deviation values of intraday and interday were <2.11% and 4.69%, respectively. Recoveries were ranged from 83.7 to 105.2%. Finally, the trace analysis method was applied to the analysis of real forensic specimens and has achieved satisfactory results.     

生物检材中巴比妥类药物固相萃取及分析方法

目的建立生物检材中巴比妥类药物的提取净化和定性定量分析方法；方法应用固相萃取法提取生物检材中巴比妥类药物，比较了巴比妥类药物固相萃取的最佳pH值、固相吸附柱等提取条件；结果确定了巴比妥类药物的GC／NPD线性范围和GC／MS检出限；结论该方法实用，提取率高，杂质干扰少，为实际案件中巴比妥类药物的提取净化和定性定量分析提供了方法和依据。