低场和高场核磁共振技术用于甲基苯丙胺及其掺杂物定量分析

Quantitative analysis of methamphetamine and adulterants by low-field and high-field NMR

目的:建立采用低场核磁共振波谱(LF-qNMR)和高场核磁共振波谱(HF-qNMR)测定缴获甲基苯丙胺晶体及片剂中甲基苯丙胺及掺杂物含量的方法。方法:采用1H定量核磁共振波谱法(^(1)H quantitative nuclear magnetic resonance,^(1)H qNMR),使用Magritek Spinsolve^(TM)80^(ULTRA)型低场核磁波谱仪和Bruker Avance Ⅲ 400 MHz型高场核磁波谱仪,以氘代甲醇(methanol-d_(4))和重水(D_(2)O)为溶剂,马来酸为内标,测定73份晶体及34份片剂样品中甲基苯丙胺和掺杂物的含量。结果:2种核磁定量法测量结果的线性相关系数(r)大于0.99,Bland-Altman图显示对于93%的样品,2种测量方法的定量结果差值位于95%一致限内,表明2种方法具有较高一致性。结论:本研究建立的LF-qNMR和HF-qNMR甲基苯丙胺晶体及片剂定量法前处理简单,检测时间短,无需待测物标准物质,可用于缴获甲基苯丙胺晶体及片剂样品中甲基苯丙胺和掺杂物含量的快速定量。

Objective:To establish a method for the quantitative analysis of methamphetamine and adulterants in seized methamphetamine crystals and tablets by low field LF-qNMR and high field HF-qNMR.Methods:^(1)H quantitative nuclear magnetic resonance(^1H qNMR)was used to determine the content of methamphetamine and adulterants in seized methamphetamine crystal samples and methamphetamine tablets by Magritek Spinsolve^(TM)80^(ULTRA)benchtop NMR spectrometer and Bruker Avance Ⅲ 400 MHz NMR spectrometer.Methanol-d_(4)and D_(2)O were used as solvent.Maleic acid was used as internal standard.Results:The coefficients of determination(r)were all greater than 0.99.Bland-Altman plots showed that the differences between two measurement methods are within the 95% limits of agreement for 93% samples.The contents of methamphetamine and adulterants obtained by LF-qNMR spectrometer and HF-qNMR spectrometer can statistically be considered equal.Conclusion:The LF-qNMR and HF-qNMR quantitative method developed in this work applied to methamphetamine quantification is validated with good results.The sample preparation is simple and test time is short.This method is suitable for fast quantitative analysis of methamphetamine and adulterants.