酸水解导致9%的去甲氢可酮和34%的可待因发生降解。待测物的转变为2-4%。每种待测物的检测浓度极低，说明酸水解产生很大的负效应，且未被LC-MS/MS检测到。实验中未发生氧可酮到去甲氧可酮的转变，氢可酮到去甲氢可酮的转变，氧吗啡酮到去甲氧吗啡酮的转变，氢吗啡酮到去甲氢吗啡酮的转变，说明N-甲基不易被切去。

结论

高温下的酸水解使3-羟基基团的甲基脱离，进而导致氧可酮转变成氧吗啡酮，可待因到吗啡的转变，去甲可待因到去甲吗啡的转变，去甲氧可酮到脱氧吗啡酮的转变，去甲氢可酮到去甲氢吗啡酮的转变。而且在90分钟水解过程中大部分的鸦片或鸦片类似物发生降解。这些负效应可导致假阴性或假阳性结果。而采用β-葡萄糖醛酸酶对这些代谢物的水解会提高检测的准确性^[3]。

参考文献

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2. Yuan, C., Heideloff, C., Kozak, M., & Wang, S. (2011, October 8). Simultaneous quantification of 19 drugs/metabolites in urine important for pain management by liquid chromatography-tandem mass spectrometry. Clinical Chemistry and Laboratory Medicine, 50(1), 95-103. doi:10.1515/cclm.2011.739

3. Sitasuwan, P., Melendez, C., Marinova, M., Mastrianni, K., Darragh, A., Ryan, E., & Lee, L. A. (2016). Degradation of Opioids and Opiates During Acid Hydrolysis Leads to Reduced Recovery Compared to Enzymatic Hydrolysis. Journal of Analytical Toxicology, 40, 601-607. doi:10.1093/jat/bkw085