Pego A M F, Roveri F L, Kuninari R Y, Leyton V, Miziara I D, Yonamine M
Department of Clinical and Toxicological Analyses, Faculty of Pharmaceutical Sciences, São Paulo University, Sao Paulo, Brazil.
Department of Clinical and Toxicological Analyses, Faculty of Pharmaceutical Sciences, São Paulo University, Sao Paulo, Brazil.
Forensic Sci Int. 2017 May;274:83-90. doi: 10.1016/j.forsciint.2016.12.024. Epub 2016 Dec 23.
Hair testing is a recognized approach when it comes to accessing historical drug use. According to the World Drug Report of United Nations Office on Drugs and Crime (UNODC) 2015, Brazil is the largest cocaine (COC) market in South America. New analytical methodologies to detect crack/cocaine analytes in hair samples are highly desirable. Here, a method consisting of a liquid-phase microextraction (LPME) as a clean-up step, followed by gas chromatography-mass spectrometry (GC-MS) analysis has been proposed. The new validated method consisted of a washing step; an overnight incubation with methanol and a quick derivatization with butylchloroformate. Once derivatized, the samples were then submitted to the LPME procedure. Limits of detection (LoD) and quantitation (LoQ) obtained were of 0.1 and 0.5ng/mg for COC 0.4 and 0.5ng/mg for anhydroecgonine methyl ester (AEME); 0.03 and 0.05 for cocaethylene (CE), respectively and 0.05ng/mg for both LoD and LoQ for benzoylecgonine (BZE). All calibration curves were linear over the scope applied, from LoQ up to 20ng/mg, with a r>0.99. Precision and accuracy assays showed acceptable %RSD values, according to international guidelines. Twelve postmortem head hair samples stemming from the Institute of Legal Medicine of Sao Paulo (IML-SP) have been analyzed, from which seven have shown to be positive for COC (0.75->20ng/mg) and BZE (0.1->20ng/mg). Apart from COC's main metabolite, four samples were also positive for CE (0.1-3.9ng/mg) and three samples for AEME (0.5-4.9ng/mg). To conclude, the LPME technique together with GC-MS analysis have shown promising results and were able to meet the demand of the laboratory of analyzing postmortem hair samples to look for all four analytes.
在获取过往吸毒情况方面，毛发检测是一种公认的方法。根据联合国毒品和犯罪问题办公室（UNODC）2015年的《世界毒品报告》，巴西是南美洲最大的可卡因（COC）市场。非常需要新的分析方法来检测毛发样本中的快克/可卡因分析物。在此，提出了一种方法，该方法包括作为净化步骤的液相微萃取（LPME），随后进行气相色谱 - 质谱（GC - MS）分析。新的经过验证的方法包括一个洗涤步骤；用甲醇过夜孵育以及用氯甲酸丁酯快速衍生化。衍生化后，样品随后进行LPME程序。获得的检测限（LoD）和定量限（LoQ）分别为：COC为0.1和0.5ng/mg，去甲芽子碱甲酯（AEME）为0.4和0.5ng/mg；可卡因乙烯酯（CE）分别为0.03和0.05，苯甲酰芽子碱（BZE）的LoD和LoQ均为0.05ng/mg。所有校准曲线在应用范围内，从LoQ到20ng/mg都是线性的，r>0.99。根据国际指南，精密度和准确度测定显示出可接受的相对标准偏差（%RSD）值。对来自圣保罗法医学研究所（IML - SP）的12份死后头部毛发样本进行了分析，其中7份样本显示COC（0.75 -> 20ng/mg）和BZE（0.1 -> 20ng/mg）呈阳性。除了COC的主要代谢物外，4份样本的CE（0.1 - 3.9ng/mg）也呈阳性，3份样本的AEME（0.5 - 4.9ng/mg）呈阳性。总之，LPME技术与GC - MS分析已显示出有前景的结果，并且能够满足实验室分析死后毛发样本以寻找所有四种分析物的需求。
