Harkey M R, Henderson G L, Zhou C
Department of Medical Pharmacology and Toxicology, School of Medicine, University of California, Davis 95616.
J Anal Toxicol. 1991 Sep-Oct;15(5):260-5. doi: 10.1093/jat/15.5.260.
A sensitive method for the simultaneous analysis of cocaine, benzoylecgonine (BE), and ecgonine methyl ester (EME) in human hair by gas chromatography/chemical ionization mass spectroscopy (GC/CIMS) is described. Hair samples are cut into 1-cm sections, washed with 1% sodium dodecylsulfate, rinsed with deionized water and methanol, and then digested overnight in a solution containing Tris buffer, sodium dodecylsulfate, Proteinase K, and dithiothreitol. Digested hair samples are extracted with Bond Elut Certify solid-phase extraction columns, derivatized with N-methyl-N-(tert-butyldimethylsilyl)-trifluoroacetamide (MTBSTFA), and analyzed by GC/CIMS using isobutane as reagent gas. This method is quantitative, does not cause degradation of cocaine, and requires as little as 5 mg of hair. Analysis is performed on a Finnigan ITS-40 ion trap mass spectrometer interfaced with a Varian 3400 gas chromatograph equipped with a Model 1075 split/splitless injector and a J&W DB-5 capillary column. Full scan spectra are used for identification of cocaine and its metabolites. Quantitation is based on peak area ratios of the MH+ ions, as follows: 304 for cocaine, 404 for BE-TBDMS, 314 for EME-TBDMS, and 340 for the internal standard, difluorococaine. This method can be used to quantitate cocaine at concentrations of 0.1 to 100 ng/mg hair. The coefficients of variation (%CV) at a drug concentration of 1 ng/mg hair are 10.3, 16.3, and 27.7% for cocaine, BE, and EME, respectively.
本文描述了一种采用气相色谱/化学电离质谱法（GC/CIMS）同时分析人发中可卡因、苯甲酰爱康宁（BE）和芽子碱甲酯（EME）的灵敏方法。将头发样本剪成1厘米长的小段，用1%的十二烷基硫酸钠洗涤，再用去离子水和甲醇冲洗，然后在含有Tris缓冲液、十二烷基硫酸钠、蛋白酶K和二硫苏糖醇的溶液中消化过夜。消化后的头发样本用Bond Elut Certify固相萃取柱萃取，用N-甲基-N-（叔丁基二甲基硅烷基）-三氟乙酰胺（MTBSTFA）衍生化，并用异丁烷作为反应气通过GC/CIMS进行分析。该方法可定量，不会导致可卡因降解，且所需头发量低至5毫克。分析在与配备1075型分流/不分流进样器和J&W DB-5毛细管柱的瓦里安3400气相色谱仪相连的菲尼根ITS-40离子阱质谱仪上进行。全扫描光谱用于鉴定可卡因及其代谢物。定量基于MH+离子的峰面积比，如下：可卡因为304，BE-TBDMS为404，EME-TBDMS为314，内标二氟可卡因 为340。该方法可用于定量头发中浓度为0.1至100 ng/mg的可卡因。在药物浓度为1 ng/mg头发时，可卡因、BE和EME的变异系数（%CV）分别为10.3%、16.3%和27.7%。
