Xu Yu, Xu Jiawei, Chen Xianxin, Fan Yi Lei, Wu Hao
Key Laboratory of Drug Monitoring and Control of Zhejiang Province, National Anti-Drug Laboratory Zhejiang Regional Center, Hangzhou, Zhejiang, China.
State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian, China.
Rapid Commun Mass Spectrom. 2023 Apr 30;37(8):e9485. doi: 10.1002/rcm.9485.
Synthetic cannabinoids are some of the most used and abused new psychoactive substances, because they can produce a stronger intense pleasure than natural cannabis. Most of the new synthetic cannabinoids are structurally similar to existing synthetic cannabinoids and can be obtained by modifying partial structures of the latter without changing their effects. Therefore, the derivatization rules and common fragmentation patterns of synthetic cannabinoids could be used for rapid screening and structural identification of them.
The derivatization rules of synthetic cannabinoids are summarized, and the common fragmentation pattern of synthetic cannabinoids including three typical cleavage pathways was explored and extended in this work based on combined mass spectrometry (MS) and density functional theory studies. Five synthetic cannabinoids in electronic cigarette oil from a drug case were separated and characterized using gas chromatography with MS and liquid chromatography coupled to high-resolution quadrupole Orbitrap MS.
The structures of five synthetic cannabinoids in seized electronic cigarette oil were deduced from electron impact ion source (EI) MS and high-resolution electrospray ionization (ESI) MS data, along with the derivatization rules and common fragmentation pattern of synthetic cannabinoids. The proposed structures of these synthetic cannabinoids were further verified via reference substances. Computational study showed that selective cleavage of these compounds was mainly controlled by spin population in EI-MS, but a tunneling effect arose from proton transfer in ESI-MS detection, which has been rarely reported in previous works.
Our results showed that EI-MS was suitable for identifying synthetic cannabinoids with aromatic ketone structure, which could also be extended to adamantane linked group. Nevertheless, synthetic cannabinoids with carbamoyl linked group were better characterized by high-resolution ESI-MS compared to EI-MS. This study demonstrated a method with promising potential for rapid and reliable screening of synthetic cannabinoids in mixtures with enhanced detection throughput and operation simplicity.
合成大麻素是一些使用和滥用最为广泛的新型精神活性物质，因为它们能产生比天然大麻更强烈的快感。大多数新型合成大麻素在结构上与现有的合成大麻素相似，并且可以通过修饰后者的部分结构而获得，同时不改变其效果。因此，合成大麻素的衍生化规则和常见裂解模式可用于对它们进行快速筛选和结构鉴定。
总结了合成大麻素的衍生化规则，并基于质谱（MS）和密度泛函理论研究，探索并扩展了合成大麻素包括三种典型裂解途径的常见裂解模式。使用气相色谱-质谱联用仪以及液相色谱-高分辨率四极杆轨道阱质谱联用仪，对一起毒品案件中电子烟油中的五种合成大麻素进行了分离和表征。
根据电子轰击离子源（EI）质谱和高分辨率电喷雾电离（ESI）质谱数据，以及合成大麻素的衍生化规则和常见裂解模式，推断出查获的电子烟油中五种合成大麻素的结构。这些合成大麻素的推定结构通过对照品进一步得到验证。计算研究表明，这些化合物在EI-MS中的选择性裂解主要受自旋布居控制，但在ESI-MS检测中质子转移会产生隧道效应，这在以往的研究中鲜有报道。
我们的结果表明，EI-MS适用于鉴定具有芳香酮结构的合成大麻素，这也可扩展至金刚烷连接基团。然而，与EI-MS相比，具有氨基甲酰连接基团的合成大麻素通过高分辨率ESI-MS能得到更好的表征。本研究展示了一种具有快速可靠筛选混合物中合成大麻素潜力的方法，具有更高的检测通量和操作简便性。
