Fully Automated Determination of Cannabinoids in Hair Samples using Headspace Solid-Phase Microextraction and Gas Chromatography-Mass Spectrometry
作者:Frank Musshoff、Heike P. Junker、Dirk W. Lachenmeier、Lars Kroener、Burkhard Madea
DOI:10.1093/jat/26.8.554
日期:2002.11.1
This paper describes a fully automated procedure using alkaline hydrolysis and headspace solid-phase microextraction (HS-SPME) followed by on-fiber derivatization and gas chromatographic-mass spectrometric (GC-MS) detection of cannabinoids in human hair samples. Ten milligrams of hair was washed with deionized water, petroleum ether, and dichloromethane. After the addition of deuterated internal standards the sample was hydrolyzed with sodium hydroxide and directly submitted to HS-SPME. After absorption of analytes for an on-fiber derivatization procedure the fiber was directly placed into the headspace of a second vial containing N-methyl-N-trimethylsilyltrifluoroacetamide (MSTFA) before GC-MS analysis. The limit f detection was 0.05 ng/mg for Δ9-tetrahydrocannabinol (THC), 0.08 ng/mg for cannabidiol (CBD), and 0.14 ng/mg for cannabinol (CBN). Absolute recoveries were in the range between 0.3 and 7.5%. Linearity was proved over a range from 0.1 to 20 ng/mg with coefficients of correlation from 0.998 to 0.999. Validation of the whole procedure revealed excellent results. In comparison with conventional methods of hair analysis this automated HS-SPME-GC-MS procedure is substantially faster. It is easy to perform without use of solvents and with minimal sample quantities, but with the same degree of sensitivity and reproducibility. The applicability was demonstrated by the analysis of 25 hair samples from several forensic cases. The following concentration ranges were determined: THC 0.29–2.20 (mean 1.7) ng/mg, CBN 0.55–4.54 (mean 1.2) ng/mg, and CBD 0.53–18.36 (mean 1.3) ng/mg. 11-nor-Δ9-Tetrahydrocannabinol-9-carboxylic acid could not be detected with this method.
本文描述了一种全自动程序,使用碱性水解和顶空固相微萃取 (HS-SPME),然后进行纤维衍生化和气相色谱-质谱 (GC-MS) 检测人头发样品中的大麻素。用去离子水、石油醚和二氯甲烷洗涤十毫克头发。添加氘代内标后,用氢氧化钠水解样品并直接进行 HS-SPME。吸收用于纤维上衍生化程序的分析物后,在进行 GC-MS 分析之前,将纤维直接放入装有 N-甲基-N-三甲基甲硅烷基三氟乙酰胺 (MSTFA) 的第二个小瓶的顶部空间中。 Δ9-四氢大麻酚 (THC) 的检测限为 0.05 ng/mg,大麻二酚 (CBD) 的检测限为 0.08 ng/mg,大麻酚 (CBN) 的检测限为 0.14 ng/mg。绝对回收率在 0.3% 至 7.5% 之间。线性范围为 0.1 至 20 ng/mg,相关系数为 0.998 至 0.999。整个过程的验证显示出良好的结果。与传统的毛发分析方法相比,这种自动化的 HS-SPME-GC-MS 程序要快得多。该方法无需使用溶剂且只需极少量的样品即可轻松执行,但具有相同程度的灵敏度和重现性。通过对几个法医案件中 25 个头发样本的分析证明了该方法的适用性。确定了以下浓度范围:THC 0.29–2.20(平均1.7)ng/mg,CBN 0.55–4.54(平均1.2)ng/mg,CBD 0.53–18.36(平均1.3)ng/mg。该方法无法检测到 11-nor-Δ9-四氢大麻酚-9-羧酸。