三甲基硅烷衍生化-气相/质谱联用法分析尿中7-氨基硝西泮

 建立了分析尿中硝西泮主要代谢物 7 氨基硝西泮 (7 ANIZ)的三甲基硅烷衍生化 气相 /质谱联用方法。尿样经乙醚 乙酸乙酯 (体积比为 99∶1 )萃取后 ,用N ,O 双 (三甲基硅 )三氟乙酰胺进行衍生化 ,检测衍生物的总离子流。根据 7 ANIZ衍生物质谱中主要特征离子的相对丰度及其质量的保留时间进行定性分析 ;用 7 氨基氯硝西泮做内标 ,根据衍生物基峰离子的质量进行定量分析。本方法中 7 ANIZ的萃取率为 82 8% ,线性范围为 1 0 μg/L～ 50 0 μg/L,检出限为 1 2 μg/L,定量限为 3 5μg/L。

Analysis of 7-Aminonitrazepam in Urine by Trimethylsilyl Derivatization-Gas Chromatography/Mass Spectrometry

A highly sensitive method has been developed for the analysis of 7-aminonitrazepam (7-ANIZ), the major metabolite of nitrazepam, in urine by trimethylsilyl derivatization-gas chromatography/mass spectrometry. Urine samples were extracted with ethyl ether-ethyl acetate (99:1, volume ratio). The extracts were derivatized with N,O-bis (trimethylsilyl) trifluoroacetamide, and the total ion current chromatograms of derivatives were acquired. 7-ANIZ was identified by the relative abundance of major characteristic ions in the mass spectrum of its derivative and the retention time of the mass chromatogram peaks of these characteristic ions. Based on the mass chromatogram of the base peak ion, quantification was performed using 7-aminoclonazepam (7-ACLZ) as the internal standard. The extraction efficiency of 7-ANIZ was 82.8%. The linear range was 10 microg/L - 500 microg/L. The limit of detection was 1.2 microg/L and the limit of quantification was 3.5 microg/L. The recoveries were 94.7% - 103.5%, and the RSDs were 3.9% - 5.4%. 7-ANIZ in the urine sample excreted by the subject over 96 h period after oral administration of 10 mg nitrazepam was measured. It is demonstrated that the method can be applied to the forensic identification.