Paul B D, Past M R, McKinley R M, Foreman J D, McWhorter L K, Snyder J J
Navy Drug Screening Laboratory, Norfolk, VA 23511-2597.
J Anal Toxicol. 1994 Oct;18(6):331-6. doi: 10.1093/jat/18.6.331.
During periodate degradation of interfering ephedrine, pseudoephedrine, and phenylpropanolamine in the extraction of methamphetamine from urine, it was observed that a small amount of methamphetamine was demethylated to amphetamine. although all three interfering phenylpropanolamines could be degraded by periodate at pH 5.2 and above, this periodate-mediated transformation of methamphetamine to amphetamine was observed only at pH 9.1 and above. Therefore, to avoid this transformation, a pH of 6.2 was used for the oxidative degradation of phenylpropanolamines. The excess periodate was then reduced with thiosulfate or ascorbic acid prior to the extraction of methamphetamine using a basic pH.
在从尿液中提取甲基苯丙胺时，对干扰性麻黄碱、伪麻黄碱和苯丙醇胺进行高碘酸盐降解的过程中，观察到少量甲基苯丙胺会脱甲基转化为苯丙胺。尽管在pH 5.2及以上时，所有三种干扰性苯丙醇胺都能被高碘酸盐降解，但甲基苯丙胺向苯丙胺的这种高碘酸盐介导的转化仅在pH 9.1及以上时才会观察到。因此，为避免这种转化，在氧化降解苯丙醇胺时使用pH 6.2。在使用碱性pH值提取甲基苯丙胺之前，先用硫代硫酸盐或抗坏血酸将过量的高碘酸盐还原。
