便携式拉曼光谱仪用于卡西酮类新精神活性物质快速定性分析探究

Rapid Qualitative Analysis of Synthetic Cathinones by Raman Spectroscopy

随着新精神活性物质在全世界范围内的蔓延,在查缉现场对疑似新精神活性物质样品进行快速定性分析是一线缉毒工作人员的迫切需求。卡西酮类物质属于卡西酮的衍生物,是新精神活性物质中的第二大类别。采用便携式拉曼光谱仪分析了70种卡西酮类化合物的拉曼光谱图,系统总结了卡西酮类物质的拉曼光谱特征,这些特征将有助于对未知卡西酮类物质的识别。所有卡西酮类化合物在(1597±19)和(1676±16)cm^(-1)处均存在由于苯环C=C键和C=O键伸缩振动产生的高强度拉曼峰,该特征可用于卡西酮类物质的识别。苯环上单取代和1,3-二取代卡西酮类化合物在992~1000cm^(-1)处存在由苯环上C—H面内变形振动引起的最强拉曼峰。3,4-亚甲二氧基取代卡西酮类化合物在(712±9)、(809±5)、(1250±16)、(1355±9)、(1444±12)、(1597±19)和(1676±16)cm^(-1)有高强度拉曼峰,且(1597±19)cm^(-1)位置的峰为肩峰。通过对70种卡西酮类化合物的拉曼光谱逐一相互比对,考察了拉曼光谱对于各种位置异构体和结构类似物的区分度。结果表明,拉曼光谱对绝大多数卡西酮类物质具有较高的区分度,特别是对苯环上甲基、卤素、甲氧基不同位置取代的位置异构体区分显著,这也是拉曼光谱对比于气质联用法和液质联用法的显著优势。拉曼光谱对于部分烷基取代基不同的结构类似物区分度较弱,但通过特征峰也能实现区分。采用拉曼光谱法对实际案件缴获样品进行了分析,除部分样品存在荧光干扰无法识别外,其他样品的拉曼分析结果与气质联用法分析结果高度一致,证明了方法的可靠性和适用性。便携式拉曼光谱仪具有操作简单、测样速度快、可进行非接触式测样等优点,可用于新精神活性物质现场快速筛查分析。

With the wide spread of new psychoactive substances(NPS)nationwide,it is an urgent need for the drug law-enforcing departments and relevant technicians to conduct an in-field rapid qualitative analysis of suspected NPS samples.Synthetic cathinones are cathinone derivatives and are the second-largest category of NPS.This study used a portable Raman spectrometer to analyze the Raman spectra of 70 synthetic cathinone reference substances.The Raman spectrum characteristics of synthetic cathinones were systematically summarized,which will help to identify the unknown synthetic cathinones.All analyzed synthetic cathinones showed strong bands at(1597±19)and(1676±16)cm^(-1),which was caused by the stretching vibration of the aromatic C C and C O bonds,and can be used to distinguish synthetic cathinones from other types of NPS.The benzene ring mono-substituted,and 1,3-disubstituted synthetic cathinones showed the most intense bands at 992~1000 cm^(-1),caused by the in-plane deformation vibration of C—H on the benzene ring.3,4-Methylenedioxy substituted synthetic cathinones showed strong bands at(712±9),(809±5),(1250±16),(1355±9),(1444±12),(1597±19),and(1676±16)cm^(-1);meanwhile,shoulder-bands were observed around(1597±19)cm^(-1).The overall discriminant ability of Raman for various regioisomers and structural analogues was also investigated.Raman spectra of 70 kinds of cathinones were compared one by one.Raman was generally distinguishable for most synthetic cathinones,especially for regioisomers substituted by the methyl,halogen and methoxy groups on the benzene ring.It is one of the significant advantages of Raman compared with GC-MS and LC-MS.Raman spectra of some structural analogues with different alkyl substitutions were highly similar but could also be distinguished by characteristic peaks.Raman was also used to analyze seized samples,and the results showed that when there was no fluorescence interference in the sample,the Raman database search result was consistent with that of GC-MS,which proved the high method reliability and applicability.The portable Raman spectrometer has the advantages of simple operation,fast and non-contact sample measurement,and can be used for the fast in-field preliminary qualitative screening of NPS.