Ciallella Heather L, Rutter Lexus R, Nisbet Lorna A, Scott Karen S
Forensic Science, Department of Chemistry and Physics, Arcadia University, Glenside, PA, United States.
Forensic and Investigative Science, School of Life Science, Anglia Ruskin University, Cambridge, United Kingdom.
Front Chem. 2020 Nov 13;8:597726. doi: 10.3389/fchem.2020.597726. eCollection 2020.
Understanding the stability of drugs in a forensic toxicology setting is critical for the evaluation of drug concentrations. Synthetic cathinones are new psychoactive substances structurally derived from cathinone, the psychoactive component of ("khat"), a shrub that is indigenous to the Middle East and East Africa. Previous research has evaluated the stability of synthetic cathinones in biological matrices, including blood preserved with the combination of NaF and KCO used in gray-top tubes. However, it does not assess their stability in blood preserved with NaEDTA, used for some clinical samples. Further, stability in unpreserved urine samples was only studied for two weeks. This research evaluates the stabilities of four Schedule I synthetic cathinones: mephedrone, MDPV (3,4-methylenedioxypyrovalerone), naphyrone, and α-PVP (alpha-pyrrolidinopentiophenone) at 20°C (room temperature), 4°C (refrigerator), and -20°C (freezer). Stability was assessed in methanolic and acetonitrile solutions, as well as in NaEDTA-preserved blood and unpreserved urine. Solutions (1 mg/L) of each drug in each matrix stored in aliquots (100 μL, solvents; 1.2 mL, biological samples; = 12) at each of the three temperatures for triplicate analysis on days 3, 7, 14, and 30. On day 0 of each study, three additional aliquots of each solution were analyzed. Biological samples underwent solid-phase extraction before analysis. All samples were analyzed in full-scan by gas chromatography-mass spectrometry (GC-MS). The results of this study show that under room temperature and refrigerator storage conditions, mephedrone, naphyrone, and MDPV will degrade in methanol. This degradation starts are early as day 3. Additionally, all four drugs will degrade in NaEDTA-preserved human whole blood samples in at least one evaluated storage environment. However, when in acetonitrile-based working solutions and unpreserved urine samples, they proved to be more stable. Methanolic working solutions and samples of NaEDTA-preserved blood containing these cathinones should be stored in the freezer and used or tested with urgency to ensure that quantitative sample analysis is as accurate as possible in forensic casework.
了解药物在法医毒理学环境中的稳定性对于评估药物浓度至关重要。合成卡西酮是一类新型精神活性物质，其结构源自中东和东非本土灌木“巧茶”中的精神活性成分卡西酮。此前的研究评估了合成卡西酮在生物基质中的稳定性，包括用灰色顶管中使用的氟化钠和碳酸钾组合保存的血液。然而，该研究并未评估它们在用于某些临床样本的乙二胺四乙酸钠（NaEDTA）保存的血液中的稳定性。此外，仅对未保存的尿液样本在两周内的稳定性进行了研究。本研究评估了四种一类合成卡西酮：甲麻黄碱、3,4-亚甲基二氧吡咯戊酮（MDPV）、萘黄酮和α-吡咯烷戊酮（α-PVP）在20°C（室温）、4°C（冰箱）和-20°C（冷冻）条件下的稳定性。在甲醇和乙腈溶液以及NaEDTA保存的血液和未保存的尿液中评估了稳定性。每种药物在每种基质中的溶液（1 mg/L）以等分试样（100 μL，溶剂；1.2 mL，生物样品；n = 12）在三个温度下储存，分别在第3、7、14和30天进行三次重复分析。在每项研究的第0天，对每种溶液的另外三个等分试样进行分析。生物样品在分析前进行固相萃取。所有样品通过气相色谱-质谱联用（GC-MS）进行全扫描分析。本研究结果表明，在室温及冰箱储存条件下，甲麻黄碱、萘黄酮和MDPV在甲醇中会降解。这种降解早在第3天就开始了。此外，在至少一种评估的储存环境中，所有四种药物在NaEDTA保存的人全血样本中都会降解。然而，当处于乙腈基工作溶液和未保存的尿液样本中时，它们被证明更稳定。含有这些卡西酮的甲醇工作溶液和NaEDTA保存的血液样本应储存在冰箱中，并尽快使用或检测，以确保在法医案件工作中定量样本分析尽可能准确。
