Johnson Leonard L, Garg Uttam
Department of Pathology and Laboratory Medicine, Children's Mercy Hospital and Clinics, Kansas City, MO, USA.
Methods Mol Biol. 2010;603:65-74. doi: 10.1007/978-1-60761-459-3_7.
Barbiturates are central nervous system depressants with sedative and hypnotic properties. Some barbiturates, with longer half-lives, are used as anticonvulsants. Their mechanism of action includes activation of gamma-aminobutyric acid (GABA) mediated neuronal transmission inhibition. Clinically used barbiturates include amobarbital, butalbital, pentobarbital, phenobarbital, secobarbital, and thiopental. Besides their therapeutic use, barbiturates are commonly abused. Their analysis is useful for both clinical and forensic proposes. Gas chromatography mass spectrometry is a commonly used method for the analysis of barbiturates. In the method described here, barbiturates from serum, plasma, or urine are extracted using an acidic phosphate buffer and methylene chloride. Barbital is used as an internal standard. The organic extract is dried and reconstituted with mixture of trimethylanilinium hydroxide (TMAH) and ethylacetate. The extract is injected into a gas chromatogram mass spectrometer where it undergoes "flash methylation" in the hot injection port. Selective ion monitoring and relative retention times are used for the identification and quantitation of barbiturates.
巴比妥类药物是具有镇静和催眠特性的中枢神经系统抑制剂。一些半衰期较长的巴比妥类药物用作抗惊厥药。它们的作用机制包括激活γ-氨基丁酸（GABA）介导的神经元传递抑制。临床使用的巴比妥类药物包括异戊巴比妥、布他比妥、戊巴比妥、苯巴比妥、司可巴比妥和硫喷妥钠。除了治疗用途外，巴比妥类药物还常被滥用。对它们的分析对临床和法医用途都很有用。气相色谱-质谱联用是分析巴比妥类药物常用的方法。在此所述的方法中，使用酸性磷酸盐缓冲液和二氯甲烷从血清、血浆或尿液中提取巴比妥类药物。巴比妥用作内标。有机提取物经干燥后，用氢氧化三甲基苯胺（TMAH）和乙酸乙酯的混合物进行复溶。提取物注入气相色谱-质谱联用仪，在热进样口中进行“快速甲基化”。选择性离子监测和相对保留时间用于巴比妥类药物的鉴定和定量。
