Psilocin is an active substance and dephosphorylated product of psilocybin formed after ingestion of mushrooms. The low stability caused by the quick oxidation of this analyte requires sensitive methods for its determination in biological matrices. In this work, we described a method development, optimization, and validation for the quantification of psilocin in authentic oral fluid samples by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Liquid-liquid extraction (LLE) was performed using 100 µL of oral fluid samples collected with Quantisal™ device and t-butyl methyl ether (MTBE) as the extraction solvent. The method showed acceptable performance, with limits of detection and quantification of 0.05 ng/mL, and the calibration model was achieved between 0.05 and 10 ng/mL. Bias and imprecision results were below -14.2% and 10.7%, respectively. Ionization suppression/enhancement were lower than -30.5%, and recovery was higher than 54.5%. Dilution integrity bias was below 14.4%. No endogenous and exogenous interferences were observed analyzing oral fluid from 10 different sources and 55 pharmaceuticals and drugs of abuse, respectively. No carryover was observed at 10 ng/mL. Psilocin was stable in oral fluid at -20°C, 4°C and 24°C up to 24, 72 and 24 h, respectively, with variations lower than 17.7%. The analyte was not stable after 3 freeze/thaw cycles, with variations between -73% and -60%. This suggests the instability of psilocin in oral fluid samples, which requires timely analysis, as soon as possible after the collection. The analyte remained stable in processed samples in autosampler (at 10°C) for up to 18 h. The method was successfully applied for the quantification of five authentic samples collected from volunteers attending parties and electronic music festivals. Psilocin concentrations ranged from 0.08 to 36.4 ng/mL. This is the first work to report psilocin concentrations in authentic oral fluid samples.

中文翻译：

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开发和验证一种灵敏的 LC-MS/MS 方法来定量真实口腔液样品中的 Psilocin

裸盖菇素是一种活性物质，是摄入蘑菇后形成的裸盖菇素的去磷酸化产物。这种分析物的快速氧化导致稳定性低，需要采用灵敏的方法来测定生物基质中的这种分析物。在这项工作中，我们描述了通过液相色谱-串联质谱 (LC-MS/MS) 定量真实口腔液样品中赛洛辛的方法开发、优化和验证。使用 Quantisal™ 装置收集的 100 µL 口腔液样品并以叔丁基甲基醚 (MTBE) 作为提取溶剂进行液液提取 (LLE)。该方法显示出可接受的性能，检测和定量限为 0.05 ng/mL，并且校准模型在 0.05 至 10 ng/mL 之间实现。偏差和不精确度结果分别低于 -14.2% 和 10.7%。电离抑制/增强低于-30.5%，回收率高于54.5%。稀释完整性偏差低于 14.4%。分别分析 10 个不同来源和 55 种药物和滥用药物的口腔液，未观察到内源性和外源性干扰。10 ng/mL 时未观察到残留。Psilocin 在口腔液中在 -20°C、4°C 和 24°C 下分别稳定稳定达 24、72 和 24 小时，变化低于 17.7%。3 次冷冻/解冻循环后，分析物不稳定，变化范围为 -73% 至 -60%。这表明口腔液样本中的赛洛辛不稳定，需要在采集后尽快进行及时分析。在自动进样器（10°C）中处理的样品中，分析物可保持稳定长达 18 小时。该方法已成功应用于对从参加聚会和电子音乐节的志愿者收集的五个真实样本进行定量。Psilocin 浓度范围为 0.08 至 36.4 ng/mL。这是第一份报告真实口腔液样本中裸鼠素浓度的工作。