高分辨质谱法快速测定芬太尼类物质及其质谱裂解规律

Rapid Determination of Fentanyl-kind Analogs and Their Mass Fragmentation Routes by High Resolution Mass Spectrometry

目的 采用UPLC-Q Exactive高分辨质谱法,对25种芬太尼类物质及2种前体化合物建立了定性定量检测方法。依据高分辨质谱(HRMS)提供的精确质量数及特征离子碎片,分析质谱裂解规律,实现无标准品的情况下对芬太尼类疑似物进行结构鉴定,解决新精神活性物质监管滞后的问题。方法 固体疑似物经甲醇超声提取后测定;液体疑似物采用乙腈进行液-液萃取,盐析分层,取乙腈层测定。采用Hypersil GOLD C18(150mm×2.1mm×1.8μm)色谱柱,以甲醇-2mmol/L乙酸铵含0.1%甲酸水溶液为流动相进行梯度洗脱;质谱采用正离子模式、全扫描及目标离子二级扫描(Full MS/dd-MS;)进行碎片信息的采集,以建立27种化合物的二级质谱谱库用于定性分析。结果 27种化合物包括同分异构体均实现了有效分离,检测限为0.05~2ng/m L,固体基质的定量限为0.5μg/kg,液体样品定量限为0.5ng/m L,加标回收率为77.03%~115.07%。在ESI模式下,芬太尼类物质的主要裂解途径:1)哌啶环上的γ-H重排到羰基氧上,发生麦氏重排(Mc Lafferty rearrangement,Mc L),羰基的β-键开裂,形成m/z 188的基峰;2)哌啶环内氢转移形成双键,激发逆Diels-Alder(RDA反应)哌啶环内裂解,形成m/z 160、146、134、132等特征离子;3)哌啶环与苯乙基部分发生N-C裂解,形成m/z 84、105的碎片离子。结论 本研究有助于已知母核的芬太尼类新精神活性物质化学结构的鉴定,可用于执法查获物中的芬太尼类物质的定性鉴别和定量检测。

Objective To develop an approach of coupling liquid chromatography with Q-Exactive high resolution mass spectrometry(HRMS) for determination of 25 fentanyl-kind analogs and 2 precursors so that both the fragmentation pathways and characteristic ions of such fentanyl-kind analogs were to analyze for providing a reference into the identifi cation of suspected fentanyl-kind chemicals without standards, meanwhile presenting a foundation for new psychoactive substances to be supervised timely or as early as possible. Methods The fentanyl-kind solid drugs were extracted with methanol under ultrasound, and those liquid ones were extracted with acetonitrile via liquid-liquid extraction and salting-out procedures. The extracts were separated through a Hypersil GOLD C18 column(150mm×2.1mm×1.8μm) where a gradient elution was perfo rmed with a mobile phase consisting of methanol and water(2mmol/L amm onium acetate solution containing 0.1% formic acid). The fragmentation ions were acquired by HRMS in positive ion mode under full-scan-data-dependent MS;(Full MS/dd-MS;). Finally, a mass-spectral library of 27 fentanyl-kind chemicals was thus established for qualitative analysis. Results 27 fentanyl-kind analogs were effectively separated along with the isomers. All the tested substances showed a low detection limit ranging among 0.05~2ng/m L and the quantitative limits for the solid-/liquid-form fentanylkind chemicals were 0.5μg/kg and 0.5ng/m L, respectively. Recoveries were all between 77.03% and 115.07%. Out from the ESI mode, the fentanyl-kind analogs mainly underwent Mc Lafferty rearrangement(McL) through γ-hydrogen of piperidinyl ring being rearranged onto carbonyl oxygen and the carbonyl β-bond cleaved, hence having afforded the product ion(m/z 188). Hydrogen-transfer reaction resulted in the product ion to render a double bond which to ignite the further retro-Diels-Alder reaction of yielding the product ions(m/z 160, 146, 134, 132). Dissociation of piperidinyl ring and phenylethyl formed the fragment ions at m/z 84, 105. Conclusions The effort made here should be facilitating the identifi cation of novel psychoactive substances with fentanyl as core(matrix) of the new synthetic chemicals, helpful to the qualitative and quantitative detection of seized chemical materials.