The emergence of potentially dangerous new psychoactive substances (NPS) is challenging for forensic laboratories, as well as the ability to develop and validate methods for a rapid and unambiguous monitoring of these compounds. Thereupon, the aim of this work was to establish a methodology for the identification and quantification of four synthetic cathinones already seized in Portugal [4-chloroethcathinone (4-CEC), α-pyrrolidinovalerophenone (α-PVP), 4-chloro-pyrrolidinovalerophenone (4-Cl-PVP) and methylenedioxypyrovalerone (MDPV)] in whole blood samples, using gas chromatography coupled to mass spectrometry (GC–MS). The analytes were extracted from blood by solid-phase extraction (SPE) and derivatized with N-methyl-N-(trimethylsilyl)trifluoroacetamide (MSTFA) with 5% trimethylchlorosilane (TMCS). For all analytes, linearity was observed from 25 (lower limit of quantification, LLOQ) to 800 ng/mL, with coefficients of determination higher than 0.99. The limits of detection (LOD) were 5 ng/mL for α-PVP, 4-Cl-PVP and MDPV and 25 ng/mL for 4-CEC. The method was selective, precise and accurate and the extraction efficiency was higher than 85% for all analytes. The target cathinones were stable under different stock conditions, being MDPV the most stable and 4-CEC the least stable compound. The validated analytical method was then applied to real samples that previously tested positive for amphetamines, but no positive samples were found for the cathinones under study. The present method describes for the first time the quantification of 4-CEC and 4-Cl-PVP in whole blood samples by GC–MS, allowing their accurate determination in forensic situations where the compounds are involved.

中文翻译：

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固相萃取和GC-MS测定血液中选定的卡西酮。

潜在危险的新型精神活性物质（NPS）的出现对于法医实验室具有挑战性，同时也具有开发和验证用于快速，明确地监控这些化合物的方法的能力。随即，这项工作的目的是建立一种鉴定和定量葡萄牙已经缉获的四种合成卡西酮的方法[4-氯乙卡西酮（4-CEC），α-吡咯烷基戊二酮（α-PVP），4-氯吡咯烷基戊二酮（使用气相色谱-质谱联用技术（GC-MS）测定全血样品中的4-Cl-PVP）和亚甲二氧基吡咯烷酮（MDPV）。通过固相萃取（SPE）从血液中萃取分析物，并用N-甲基-N衍生化-（三甲基甲硅烷基）三氟乙酰胺（MSTFA）与5％三甲基氯硅烷（TMCS）。对于所有分析物，线性度从25（定量下限，LLOQ）到800 ng / mL均可见，测定系数高于0.99。α-PVP，4-Cl-PVP和MDPV的检出限（LOD）为5 ng / mL，4-CEC为25 ng / mL。该方法具有选择性，精确和准确的特点，所有分析物的提取效率均高于85％。目标卡西酮在不同的储备条件下是稳定的，MDPV是最稳定的化合物，而4-CEC是最不稳定的化合物。然后，将经过验证的分析方法应用于实际测试过的苯丙胺呈阳性的真实样品，但未发现所研究的卡西酮呈阳性的样品。