Department of Cosmetic Science, Providence University, Taichung, 433, Taiwan.
School of Pharmacy, Taipei Medical University, 250 Wu-Hsing Street, Taipei, 110, Taiwan.
Rapid Commun Mass Spectrom. 2020 Apr;34 Suppl 1:e8579. doi: 10.1002/rcm.8579. Epub 2020 Feb 5.
The presence of α-pyrrolidinovalerophenone (α-PVP) and its metabolites in urine is evidence of the administration of α-PVP. A toxicological challenge is that the metabolites of α-PVP exhibit amphoteric properties, which make them unsuitable for detection using gas chromatography-mass spectrometry (GC/MS). In the study reported, proper derivatization and sample extraction were essential for improving the sensitivity for GC/MS analysis.
An automated solid-phase extraction (SPE) method has been developed and optimized. The derivatization efficiency was tested using longer reaction time and the addition of polar pyridine into a mixture of N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) with 1% trimethylchlorosilane. Method validation, including linearity, limit of detection, precision, accuracy, and recovery, was evaluated using automatic SPE and GC/MS.
The results suggested that adding pyridine to BSTFA (1:1, v/v) significantly improved derivatization efficiency and precision. After optimization, the linear range was from 25 to 1000 ng mL with R > 0.9950. The limit of detection was 5 ng mL for α-PVP and 25 ng mL for OH-α-PVP. The recovery for SPE was over 88%. The inter-day and intra-day precisions were less than 15%. A forensic sample has been found containing α-PVP (67.3 ng mL ) and OH-α-PVP (560.2 ng mL ).
This study is the first to validate an auto-SPE-GC/MS method for the quantification and qualification of α-PVP and OH-α-PVP in urine. We have successfully improved the derivatization efficiency and developed a sensitive and semi-automatic approach. This approach is desirable for the detection of synthetic cathinone at trace levels in biological samples.
α-吡咯戊基苯丙酮（α-PVP）及其代谢物在尿液中的存在是 α-PVP 给药的证据。一个毒理学挑战是，α-PVP 的代谢物表现出两性性质，这使得它们不适合使用气相色谱-质谱联用技术（GC/MS）进行检测。在报告的研究中，适当的衍生化和样品提取对于提高 GC/MS 分析的灵敏度是必不可少的。
开发并优化了一种自动化固相萃取（SPE）方法。通过更长的反应时间和在 N,O-双（三甲基硅基）三氟乙酰胺（BSTFA）中加入极性吡啶来测试衍生化效率，BSTFA 与 1%三甲基氯硅烷的混合物。使用自动 SPE 和 GC/MS 评估方法验证，包括线性、检测限、精密度、准确度和回收率。
结果表明，在 BSTFA 中加入吡啶（1:1，v/v）显著提高了衍生化效率和精密度。经过优化，线性范围为 25 至 1000ng/mL，R>0.9950。α-PVP 的检测限为 5ng/mL，OH-α-PVP 的检测限为 25ng/mL。SPE 的回收率超过 88%。日内和日间精密度小于 15%。发现一份法医样本中含有 α-PVP（67.3ng/mL）和 OH-α-PVP（560.2ng/mL）。
本研究首次验证了自动 SPE-GC/MS 方法用于尿液中 α-PVP 和 OH-α-PVP 的定量和定性分析。我们成功地提高了衍生化效率，并开发了一种灵敏的半自动方法。这种方法适用于痕量生物样本中合成卡西酮的检测。
