-
近年来,我国对非药用类麻醉药品和精神药品的管控力度不断加大,管控速度不断加快,但一些不法分子为逃避法律制裁,通过保留管制毒品的骨架结构,改变烷基的碳链长度[1-3]、变换卤素取代[4-6]等方式进行简单的结构修饰,制造出新精神活性物质(NPS),给毒品检验工作带来了极大挑战[7-8]。
苯环己哌啶类新精神活性物质属于解离性精神药物,主要通过与中枢神经系统中N-甲基-D-天冬氨酸(NMDA)受体的拮抗作用产生麻醉、镇痛等作用[9],如苯环己哌啶(PCP)、氯胺酮(ketamine)、乙环利定(PCE)、氟胺酮(2-FDCK)等[10]。2021年,我国发布公告,将2-FDCK列入《非药用类麻醉药品和精神药品管制品种增补目录》[11]。随后,市面上开始陆续出现溴胺酮(2-BDCK)、甲基胺酮(2-MDCK)、乙基氟胺酮(2-FXE)、2-乙氨基-2-苯基环己酮(2-oxo-PCE)等苯环己哌啶类NPS来代替管制的2-FDCK[12-13]。2024年,2-BDCK、2-MDCK、2-FXE等被列入管控目录[14],毒品市场上又开始出现新的替代品。为打击新型毒品犯罪,亟需建立一种快速鉴定NPS的方法。
目前,鉴别新出现的NPS有气相色谱-质谱(GC-MS)、液相色谱-四极杆飞行时间质谱(LC-QTOF MS)、核磁共振波谱(NMR)、傅里叶变换红外光谱(FT-IR)等方法[1-7,15]。其中,GC-MS和LC-QTOF MS需要标准物质或参考物质进行比对;NMR和FT-IR则需要较高纯度的样品。
本研究在缺少标准物质或参考物质,且样品量较少,无法进行NMR分析的情况下,利用已知相似结构物质的质谱特征和裂解规律,采用GC-MS和LC-QTOF MS法对新出现的未知NPS进行结构推断,旨为毒品实验室在分析此类案件时提供技术参考。
-
GC-2030/GCMS-TQ8040 NX GC-MS:日本Shimadzu公司产品,配有电子电离(EI)源;LC40-X500R LC-QTOF-MS:美国SCIEX公司产品,配有电喷雾电离(ESI)源。
-
2-oxo-PCE(纯度≥99%):上海原思标物科技有限公司产品;水为超纯水;甲醇、乙腈、甲酸均为色谱级,其他试剂均为分析纯。
-
色谱条件:VF-5MS色谱柱(30 m×0.25 mm,0.25 μm);升温程序为初始温度80 ℃,保持1 min,以20 ℃/min升至280 ℃,保持4 min;载气(99.99%He)流速1.0 mL/min;进样口温度280 ℃;分流进样,分流比20:1。
质谱条件:EI源;传输线温度280 ℃;离子源温度300 ℃;电子能量70 eV;质量扫描范围m/z 45~450;溶剂延迟3.5 min; Full scan扫描模式。
-
色谱条件:Luna Omega Polar C18色谱柱(2.1 mm×100 mm,1.6 μm);流动相A为0.1%甲酸-水溶液,B为乙腈;柱温40 ℃;流速0.3 mL/min;进样量5 μL;梯度洗脱条件为0~1 min(5%B),1~7 min(5%~70%B),7~10 min(70%~98%B), 10~12 min(98%B),12~15 min(5%B)。
质谱条件:ESI源,正离子检测模式;离子喷雾电压5 500 V;离子源温度550 ℃;离子源气体1(雾化器气体,gas1)压强379.2 kPa;离子源气体2(辅助加热气体,gas2)压强344.7 kPa;气帘气压强241.3 kPa;去簇电压60 V;一级全扫描碰撞能量(CE)10 eV,质量扫描范围m/z 80~1 000;子离子扫描CE为35 eV,碰撞能量扩展(CES)15 eV,质量扫描范围m/z 30~1 000;信息依赖性扫描(IDA)模式,选择响应值超过100 cps进行二级质谱扫描,并开启动态背景扣除(DBS)以减少干扰。
-
将缴获的电子烟油(示于图1)混合均匀,吸取10 μL于10 mL离心试管中,加入2 mL甲醇超声溶解,涡旋混匀,然后加入适量的无水硫酸钠去除水分,过0.2 μm有机滤膜。取1 mL滤液于样品瓶中进行GC-MS分析;另取10 μL滤液至样品瓶中,加入990 μL甲醇,混匀后进行LC-QTOF MS分析。
-
将缴获的电子烟油按1.4节方法处理后进行GC-MS分析,其总离子流图示于图2。可以发现,在保留时间7.69 min处出现一未知色谱峰,主要特征碎片离子有m/z 174(基峰)、203、104、160等,其质谱图示于图3。通过与自建标准物质谱库、SWGDRUG谱库、NIST谱库等数据库进行谱库检索,匹配结果为1-苯基-N-丙基环戊胺,分子式为C14H21N,分子质量为203,匹配度为88%。进一步分析该未知物的质谱图发现,其特征碎片离子m/z 77、91、104、117、132、146与2-oxo-PCE的特征碎片离子基本相同,但m/z 174、203与2-oxo-PCE的m/z 160、189相差14 u,相当于1个−CH2−,推测该未知物的结构与2-oxo-PCE相似,属于同一类物质。为进一步确认该未知物的结构,继续对电子烟油和2-oxo-PCE进行LC-QTOF MS分析。
-
将缴获的电子烟油按1.4节方法处理后进行LC-QTOF MS分析,采用非靶向未知物筛查数据处理方法,发现在保留时间3.099 min处出现强度较大的色谱峰,同时得到其一级和二级高分辨质谱图,分别示于图4、5。经仪器自带的质谱谱库和自建标准物质谱库检索未得到结果,但利用分子式拟合软件Formula Finder对一级高分辨质谱准分子离子[M+H]+ m/z 232.168 9拟合得到该未知物的分子式为C15H21NO,理论质量数[M+H]+为232.169 6,质量偏差为−3.01×10−6,与2-oxo-PCE(C14H19NO)相差1个−CH2−。因此,确定GC-MS谱库检索结果不正确,目标物并非1-苯基-N-丙基环戊胺。进一步分析该未知物的二级高分辨质谱图,除准分子离子峰外,未知物的主要特征碎片离子有m/z 91.054 0、145.100 9、173.096 0、 117.069 6、 129.069 9、 67.054 3、155.085 5,与2-oxo-PCE的主要特征碎片离子基本一致,由此推断,该未知物的骨架结构与2-oxo-PCE一致。
-
GC-MS和LC-QTOF MS分析结果分别列于表1、2。可以得出,未知物与2-oxo-PCE的骨架结构基本一致,且其分子质量与2-oxo-PCE相差14 u,部分特征碎片离子也相差14 u,相当于1个−CH2−,只能通过改变2-oxo-PCE结构中N上的乙基为丙基来形成。结合文献[16]报道,推断该未知物为2-丙氨基-2-苯基环己酮,即2-oxo-PCPr,其结构示于图6。
在EI-MS条件下,未知物的分子离子峰[M]+·为m/z 231,其强度较小,主要裂解途径与2-oxo-PCE相似。分子离子先失去CO后生成特征碎片离子[M−CO]+·,再经过电子转移,分别失去C2H5·、C3H7·、C4H9·、C5H11·或C6H13·,形成[M−CO−C2H5·]+、[M−CO−C3H7·]+、[M−CO−C4H9·]+、[M−CO−C5H11·]+或[M−CO−C6H13·]+等特征碎片离子,然后进一步形成䓬鎓离子m/z 91[C7H7]+和苯环离子m/z 77[C6H5]+,同时还形成亚胺正离子m/z 44[C2H6N]+和m/z 58[C3H8N]+,可能的裂解途径示于图7。
在ESI-MS条件下,未知物的准分子离子峰[M+H]+为m/z 232.169 5,主要裂解途径与2-oxo-PCE相似。准分子离子失去H2O(18 u)生成特征碎片离子[C14H18N]+,继续发生C−N键断裂,失去NH2CH2CH3或NH2CH2CH2CH3(45 u或59 u),生成特征碎片离子[C12H11]+;或者准分子离子先发生C−N键断裂,失去NH2CH2CH3或NH2CH2CH2CH3,生成特征碎片离子[C2H8N]+或[C3H10N]+和[C12H13O]+,[C12H13O]+继续失去CO(28 u)和C2H4O(44 u),生成特征碎片离子[C11H13]+和[C10H9]+,并进一步生成特征碎片离子[C7H7]+,可能的裂解途径示于图8。
-
本文采用GC-MS和LC-QTOF MS法检验真实案件缴获的电子烟油中苯环哌啶类NPS,通过LC-QTOF MS确定精确分子质量,并推断分子式,结合EI-MS和ESI-MS谱图的特征碎片离子和裂解规律,采用结构类似物质2-oxo-PCE进行对比,成功分析出电子烟油中含有新出现的苯环哌啶类2-oxo-PCPr,并推测可能的裂解途径。该方法可为类似案件的毒品分析提供思路。
缴获电子烟油中苯环己哌啶类新精神活性物质2-丙氨基-2-苯基环己酮的鉴定分析
Identification of a New Psychoactive Substances of Phencyclidine-type, 2-Oxo-PCPr in Seized e-Cigarette Oil
-
摘要: 本研究建立了气相色谱-质谱(GC-MS)和液相色谱-四极杆飞行时间质谱(LC-QTOF MS)检测电子烟油中苯环己哌啶类新精神活性物质(NPSs)的方法。将缴获的电子烟油经提取后进行GC-MS和LC-QTOF MS分析,获得相应的质谱图,并分析特征离子和裂解规律。结果表明,在电子烟油中检出一种未知物成分,其质谱特征碎片离子及裂解规律与2-乙氨基-2-苯基环己酮(2-oxo-PCE)相似;通过质谱解析,推断该未知物为苯环己哌啶类新精神活性物质2-丙氨基-2-苯基环己酮(2-oxo-PCPr)。本方法在缺少标准物质或参考物质,且样品量较少的情况下,成功鉴定出未知物成分,可为新精神活性物质的鉴定提供参考。Abstract: The new psychoactive substances (NPSs) are defined as a category of substances of abuse, either in a pure form or a preparation, that are not listed in the control table by the 1961 Single Convention on Narcotic Drugs or the 1971 Convention on Psychotropic Substances, but may pose a public health threat. In July 2024, a total of
1245 individual NPSs have been reported to the United Nations Office on Drugs and Crime (UNODC) by 142 countries and territories worldwide. The growth in the number of NPSs has become a great challenge and a potential threat to global public health. The phencyclidine-type substances are classified into the group of dissociative NPSs, because they produce feelings of detachment and dissociation from self and the environment. These effects are produced through antagonism of ionotropic N-methyl-D-aspartate (NMDA) receptors in the central nervous system. Some of phencyclidine-type substances are scheduled as narcotics under the Administration of Non-Pharmaceutical Narcotic Drugs and Psychotropic Substances in China, including ketamine, 2-(2-fluoromophenyl)-2-(methylamino) cyclohexan-1-one (2-FDCK), 2-(ethylamino)-2-Phenylcyclohexan-1-one (2-oxo-PCE), 2-(2-bromophenyl)-2-(methylamino) cyclohexan-1-one (2-BDCK), 2-(ethylamino)-2-(2-fluorophenyl) cyclohexan-1-one (2-FXE), 2-(methylamino)-2-(2-methylphenyl) cyclohexan-1-one (2-MDCK) and so on. However, some new phencyclidine-type substances are produced by introducing slight modifications to the chemical structure of controlled substances to circumvent drug controls. These emerging substances have posed a significant challenge to the identification of forensic science laboratory around the world. Therefore, the knowledge of MS fragmentation pathways of known structure NPSs is very important for the structure elucidation of emerging new type of NPSs. In this study, a method based on gas chromatography-mass spectrometry (GC-MS) and liquid chromatography quadrupole time-of-flight mass spectrometry (LC-QTOF MS) was established for the analysis of phencyclidine-type NPSs in e-cigarette oil. The e-cigarette oil was extracted by methanol, then analyzed by GC-MS and LC-QTOF MS. The mass spectra were obtained under electron impact (EI) and electrospray ionization (ESI) modes, respectively, the structure and fragmentation pathways of main fragment ions were deduced. Finally, an unknown component was identified as a NPS of phencyclidine-type, 2-(propylamino)-2-phenylcyclohexan-1-one (2-oxo-PCPr), through structural analysis. Its characteristic fragment ion information acquired by GC-MS and LC-QTOF MS was similar to 2-oxo-PCE. This study provides a reference approach for the identification of small amount of NPSs by comprehensive analysis of their electron ionization mass spectrometry (EI-MS) and electron ionization tandem mass spectrometry (ESI-MS/MS) fragmentation patterns in the absence of reference materials. -
-
表 1 未知物和2-oxo-PCE的EI-MS特征碎片离子
Table 1. Characteristic fragment ions of unknown and 2-oxo-PCE under EI-MS mode
名称
Name分子式
Molecular formula保留时间
tR/min主要特征碎片离子
Main characteristic fragment ion (m/z)未知物 C15H21NO 7.695 58 77 91 104 117 132 146 160 174 203 2-oxo-PCE C14H19NO 7.165 44 77 91 104 117 132 146 160 189 表 2 未知物和2-oxo-PCE的ESI-MS特征碎片离子
Table 2. Characteristic fragment ions of unknown and 2-oxo-PCE under ESI-MS mode
名称
Name保留时间
tR/min化学式
Chemical formula理论值
Theoretical mass (m/z)实测值
Experimental mass (m/z)误差
Error/×10−6未知物 3.105 C15H22NO+ 232.1696 232.1695 −0.43 C15H20N+ 214.1590 214.1591 0.47 C12H13O+ 173.0961 173.0960 −0.58 C12H11+ 155.0855 155.0855 0.00 C11H13+ 145.1012 145.1009 −2.07 C10H9+ 129.0699 129.0699 0.00 C9H9+ 117.0699 117.0696 −2.56 C7H7+ 91.0542 91.0540 −2.20 C5H7+ 67.0542 67.0543 1.49 C3H10N+ 60.0808 60.0810 3.33 2-oxo-PCE 2.961 C14H20NO+ 218.1539 218.1536 −1.38 C14H18N+ 200.1434 200.1428 −3.00 C12H13O+ 173.0961 173.0962 0.58 C12H11+ 155.0855 155.0861 3.87 C11H13+ 145.1012 145.1013 0.69 C10H9+ 129.0699 129.0698 −0.77 C9H9+ 117.0699 117.0699 0.00 C7H7+ 91.0542 91.0543 1.10 C5H7+ 67.0542 67.0544 2.98 C2H8N+ 46.0651 46.0652 2.17 -
[1] 王跨陡, 袁晓亮, 何思阳, 盛振海, 刘文斌, 曹芳琦. 合成卡西酮类新精神活性物质4-F-3-Me-ɑ-PVP的检测[J]. 药物分析杂志, 2023, 43(6): 950 -956 . WANG Kuadou, YUAN Xiaoliang, HE Siyang, SHENG Zhenhai, LIU Wenbin, CAO Fangqi. Identification of a new psychoactive substance of synthetic cathinone named 4-F-3-Me-ɑ-PVP[J]. Chinese Journal of Pharmaceutical Analysis, 2023, 43(6):950 -956 (in Chinese).[2] 郭颖, 吴波, 杨乔, 王学虎, 崔明伟, 苏梦翔. 缴获电子烟油中新型合成大麻素ADB-BUTINACA和4-Fluoro ABUTINACA的鉴定分析[J]. 中国司法鉴定, 2023(3): 53 -60 . doi: 10.3969/j.issn.1671-2072.2023.03.007 GUO Ying, WU Bo, YANG Qiao, WANG Xuehu, CUI Mingwei, SU Mengxiang. Identification of new synthetic cannabinoids psychoactive substances ADB-BUTINACA and 4-fluoro ABUTINACA in the seized electronic cigarette oil[J]. Chinese Journal of Forensic Sciences, 2023(3):53 -60 (in Chinese). doi: 10.3969/j.issn.1671-2072.2023.03.007[3] 钱振华, 杨虹贤, 刘翠梅. 苯二氮卓类新精神活性物质Flubromazolam的快速检测[J]. 分析试验室, 2018, 37(10): 1 133-1 136. QIAN Zhenhua, YANG Hongxian, LIU Cuimei. Rapid detection of designer benzodiazepine flubromazolam by GC-MS and UPLC-Q-TOF MS[J]. Chinese Journal of Analysis Laboratory, 2018, 37(10): 1 133-1 136(in Chinese). [4] 胡庆坤, 刘昕, 郭靖, 徐若沦. 新型苯环己哌啶衍生物溴胺酮的表征与分析[J]. 刑事技术, 2024, 49(1): 31 -37 . HU Qingkun, LIU Xin, GUO Jing, XU Ruolun. Characterization and identification of Br-ketamine: a novel phenyclohexidine derivative[J]. Forensic Science and Technology, 2024, 49(1):31 -37 (in Chinese).[5] 庄顺, 叶树海, 林葭, 林坚, 李航麒. 疑似毒品中新型麻醉活性物质氟胺酮的GC/MS检验[J]. 中国法医学杂志, 2020, 35(5): 508 -509, 513 . ZHUANG Shun, YE Shuhai, LIN Jia, LIN Jian, LI Hangqi. Identification of F-ketamine in suspected drugs by GC/MS[J]. Chinese Journal of Forensic Medicine, 2020, 35(5):508 -509, 513 (in Chinese).[6] 陈乐, 蒙卫宁. GC-MS法检测氟胺酮和N-乙基氟胺酮[J]. 化工技术与开发, 2024, 53(11): 56 -60 . doi: 10.3969/j.issn.1671-9905.2024.11.012 CHEN Le, MENG Weining. Determination of fluamine and N-ethylfluamine by GC-MS[J]. Technology & Development of Chemical Industry, 2024, 53(11):56 -60 (in Chinese). doi: 10.3969/j.issn.1671-9905.2024.11.012[7] 聂宗炀, 胡伟, 李玲玉, 章青波, 黄欣, 李波. 3种新精神活性物质的结构确证及未知毒品的定性鉴定[J]. 法医学杂志, 2024, 40(4): 340 -351 . doi: 10.12116/j.issn.1004-5619.2023.330101 NIE Zongyang, HU Wei, LI Lingyu, ZHANG Qingbo, HUANG Xin, LI Bo. Structure confirmation of three new psychoactive substances and qualitative identification of unknown substances[J]. Journal of Forensic Medicine, 2024, 40(4):340 -351 (in Chinese). doi: 10.12116/j.issn.1004-5619.2023.330101[8] 范一雷, 陈显鑫, 薛锦锋, 吴昊, 柯星, 徐雨. 新型靛红腙类合成大麻素质谱裂解规律研究[J]. 分析试验室, 2024, 43(1): 57 -63 . FAN Yilei, CHEN Xianxin, XUE Jinfeng, WU Hao, KE Xing, XU Yu. Investigation of mass spectrometry-based fragmentation patterns of new “OXIZID” synthetic cannabinoids[J]. Chinese Journal of Analysis Laboratory, 2024, 43(1):57 -63 (in Chinese).[9] KAPUR S, SEEMAN P. NMDA receptor antagonists ketamine and PCP have direct effects on the dopamine D2 and serotonin 5-HT2 receptors-implications for models of schizophrenia[J]. Molecular Psychiatry, 2002, 7(8): 837 -844 . doi: 10.1038/sj.mp.4001093[10] MORRIS H, WALLACH J. From PCP to MXE: a comprehensive review of the non-medical use of dissociative drugs[J]. Drug Testing and Analysis, 2014, 6(7/8): 614 -632 .[11] 公安部, 国家卫生健康委员会, 国家药品监督管理局. 关于将合成大麻素类物质和氟胺酮等18种物质列入《非药用类麻醉药品和精神药品管制品种增补目录》的公告[EB/OL]. (2021-03-15)[2024-12-30]. https://www.mps.gov.cn/n6557558/c7881251/content.html. [12] 范一雷, 陈显鑫, 张宏建, 吴昊, 徐雨. 质谱识别新型合成苯环己哌啶类物质氟胺酮异构体[J]. 分析试验室, 2023, 42(3): 338 -343 . FAN Yilei, CHEN Xianxin, ZHANG Hongjian, WU Hao, XU Yu. Differentiation of novel synthetic phenylcyclohexyl piperidines fluamine isomers by mass spectrometry[J]. Chinese Journal of Analysis Laboratory, 2023, 42(3):338 -343 (in Chinese).[13] 王学虎, 花镇东. 疑似毒品“甲基胺酮” 的检验[J]. 中国药物依赖性杂志, 2023, 32(4): 257 -261 . WANG Xuehu, HUA Zhendong. Rapid identification of “2-methyl-deschloro-ketamine” of suspected drug by mass spectrometry[J]. Chinese Journal of Drug Dependence, 2023, 32(4):257 -261 (in Chinese).[14] 公安部, 国家卫生健康委, 国家药监局. 关于将溴啡等46种物质列入《非药用类麻醉药品和精神药品管制品种增补目录》的公告[EB/OL]. (2024-06-16)[2024-12-30]. https://www.mps.gov.cn/n6557558/c9621723/content.html. [15] XU F, WEI W, SHAN X, WANG R, LIU L. Identification and characterization of novel synthetic cannabinoid ethyl-2-(1-(5-fluoropentyl)-1H-indole-3-carboxamido)-3, 3-dimethylbutanoate (5F-EDMB-PICA)[J]. Forensic Toxicology, 2022, 40(1): 163 -172 . doi: 10.1007/s11419-021-00605-7[16] FRANKENFELD F, WAGMANN L, ABELIAN A, WALLACH J, ADEJARE A, BRANDT S D, MEYER M R. In vivo and in vitro metabolic fate and urinary detectability of five deschloroketamine derivatives studied by means of hyphenated mass spectrometry[J]. Metabolites, 2024, 14(5): 270 . doi: 10.3390/metabo14050270 -