PDF(Pubmed)
Abstract：
Isomerization commonly occurs in synthetic cannabinoids (SCs). Owing to the few differences in their structure and properties, it is difficult to simultaneously separate and identify them. Thus, the identification of synthetic cannabinoids is challenging, posing a threat to public security. This study aims to separate and identify four SCs, which are 2-[1-(5-fluoropentyl)-1H-indole-3-formylamino]-3,3-dimethylbutyrate methyl ester (5F-MDMB-PICA), 2-[1-(5-fluoropentyl)-1H-indole-3-formylamino]-3-methylbutyrate ethyl ester (5F-EMB-PICA), N-(1-amino-2,2-dimethyl-1-oxobutyl-2-yl)-1-butyl-1H-indazole-3-formamide (ADB-BINACA), N-(1-carbamoyl-2-methylpropyl)-1-pentyl indazole-3-formamide (AB-PINACA).Supercritical fluid chromatography-mass spectroscopy (SFC-MS) can realize the effective separation of some cannabinoid isomers. However, most laboratories are not equipped with SFC-MS systems. Ultra-high performance liquid chromatography-high resolution mass spectroscopy (UHPLC-HRMS) effectively combines the excellent efficient separation characteristics of liquid chromatography and the powerful qualitative ability of mass spectrometry. It is a commonly used technical method for the detection of amide synthetic cannabinoids and their metabolites in vivo and in vitro because of its advantages of high accuracy and efficiency. Liquid chromatography allows the separation of tested components by exploiting the difference in the partition coefficients between the mobile and stationary phases. When the two phases are in relative motion, the tested components are divided between the two phases, facilitating the separation and analysis of each component. Although the difference in the polarities of the tested amide synthetic cannabinoid isomeric substances is extremely small, liquid chromatography can induce a strong separation effect. The advantages of UHPLC-HRMS include high resolution imparted by mass spectrometry and high sensitivity, allowing its application in the qualitative analysis of various substances. Through UHPLC-HRMS, trace analytes at the nanogram scale as well as pure drugs and their metabolites in biosamples can be detected. This study proposed a method for the determination of two pairs of amide synthetic cannabinoid isomers-5F-EMB-PICA and 5F-MDMB-PICA, ADB-BINACA and AB-PINACA-through UHPLC-HRMS. A Hypersil GOLD C18 column (100 mm×2.1 mm, 1.9 μm) was selected for separation via liquid chromatography, and gradient elution was performed with methanol containing 0.1% formic acid and a 0.1% formic acid aqueous solution containing 10 mmol/L ammonium formate. Full scan/data-dependent secondary mass spectrometry (Full MS/dd-MS2) was conducted in the positive ion mode for detection. The results indicated that the four synthetic cannabinoid isomers could be accurately detected under the abovementioned conditions. The resolution between 5F-EMB-PICA and 5F-MDMB-PICA was 2.06, while that between ADB-BINACA and AB-PINACA was 1.22, indicating the effective separation and detection of both pairs. Furthermore, method validation was conducted to ensure the accuracy of the proposed method. The relationship of the four amide synthetic cannabinoid isomers exhibited excellent linearity. The correlation coefficients (R2) were >0.99. Moreover, the matrix effects of the four SCs in hair samples were between 88.67% and 111.76% and the recoveries were 96.23%-105.11%. The intra-day and inter-day precisions (RSDs) were <10%. The proposed method was used to identify the case materials. AB-PINACA was detected in a hair sample at a content of 0.73 μg/g. 5F-MDMB-PICA was detected in a tobacco sample at a content of 11.3 mg/g. The results indicate that the proposed method can be used for the examination of practical samples conducted by public security organizations. This study provides a reference method for the identification of synthetic cannabinoid isomers.
摘要：
异构化通常发生在合成大麻素(SC)中。由于它们的结构和性质几乎没有差异，很难同时分离和识别它们。因此，合成大麻素的鉴定具有挑战性，对公共安全构成威胁。本研究旨在分离和鉴定四种SCs，它们是2-[1-(5-氟戊基)-1H-吲哚-3-甲酰氨基]-3,3-二甲基丁酸甲酯(5F-MDMB-PICA)，2-[1-(5-氟戊基)-1H-吲哚-3-甲酰氨基]-3-甲基丁酸乙酯(5F-EMB-PICA),N-(1-氨基-2,2-二甲基-1-氧代丁基-2-基)-1-丁基-1H-吲哚-3-甲酰胺(ADB-BINACA),N-(1-氨基甲酰基-2-甲基丙基)-1-戊基吲哚-3-甲酰胺(AB-PINACA)。超临界流体色谱-质谱联用技术(SFC-MS)可以实现某些大麻素异构体的有效分离。然而,大多数实验室没有配备SFC-MS系统。超高效液相色谱-高分辨率质谱（UHPLC-HRMS）有效地结合了液相色谱的出色高效分离特性和质谱的强大定性能力。该方法具有准确度高、效率高等优点,是体内外检测酰胺类合成大麻素及其代谢产物的常用技术方法。液相色谱可以通过利用流动相和固定相之间的分配系数差异来分离被测组分。当两个阶段相对运动时，被测试的组件被分为两个阶段，便于每个组件的分离和分析。尽管所测试的酰胺合成大麻素异构物质的极性差异非常小，液相色谱可以诱导强烈的分离效果。UHPLC-HRMS的优点包括质谱赋予的高分辨率和高灵敏度，允许其在各种物质的定性分析中的应用。通过UHPLC-HRMS,可以检测到纳米尺度的痕量分析物以及生物样品中的纯药物及其代谢物。这项研究提出了一种测定两对酰胺合成大麻素异构体-5F-EMB-PICA和5F-MDMB-PICA的方法，ADB-BINACA和AB-PINACA-通过UHPLC-HRMS。HypersilGOLDC18色谱柱(100mm×2.1mm,1.9μm)通过液相色谱法选择分离，用含有0.1%甲酸的甲醇和含有10mmol/L甲酸铵的0.1%甲酸水溶液进行梯度洗脱。在正离子模式下进行全扫描/数据依赖性二次质谱(全MS/dd-MS2)用于检测。结果表明,在上述条件下合成的4种大麻素异构体均能得到准确的检测。5F-EMB-PICA和5F-MDMB-PICA之间的分辨率为2.06，而ADB-BINACA和AB-PINACA之间的分辨率为1.22，表明两对的有效分离和检测。此外，进行了方法验证,以确保所提出方法的准确性。四种酰胺合成大麻素异构体的关系表现出优异的线性。相关系数(R2)>0.99。此外，头发样品中四种SCs的基质效应在88.67％至111.76％之间，回收率为96.23％-105.11％。日内和日间精确度(RSD)<10%。该方法用于识别案例材料。在头发样品中检测到AB-PINACA的含量为0.73μg/g。在烟草样品中检测到5F-MDMB-PICA的含量为11.3mg/g。结果表明，该方法可用于公安机关实际样本的检验。本研究为合成大麻素异构体的鉴定提供了参考方法。
