2-(苯并吖啶酮)-乙基咪唑酸酯探针对荧光和质谱的双增敏作用

Dual-Sensitive Probe of 2-(Benzoacridin)ethyl-imidazole-1-carboxylate for Determination of Aliphatic Amine with Fluorescence and Online Atmospheric Pressure Chemical Ionization Mass Spectrometry Identification

采用3种不同衍生方法对胺类化合物进行标记,比较衍生效率的差别,给出最优方法:5-(2-羟乙基)-(苯并吖啶酮与N,N-羰基双咪唑(CDI)缩合形成的双敏感探针2-(苯并吖啶酮)-乙基咪唑酸酯(BAEIC)与胺的衍生效率最高,产物稳定。BAEIC在N,N-二甲基甲酰胺(DMF)溶剂中以4-二甲氨基吡啶(DMAP)为催化剂,在80℃条件下与胺反应生成的亲核取代物,不仅表现出强烈的荧光,同时具有很强的质谱离子化能力。估算了衍生物在乙腈和甲醇水溶液中百分离子化值δ在5.62%～58.08%和2.14%～56.58%范围内。本方法具有良好的重现性,激发和发射波长为λex/λem=280/510nm,荧光检出限为0.12～0.59μg/L(8.6～79fmol);在线APCI-MS检出限为1.9～14μg/L(544～825fmol)。

With comparison of three different methods for the marking of amines compound,an optimal derivatization method was selected.5-（2-Hydroxyethyl） benzoacridine（HBA） reacts with coupling agent N,N＇carbonyldiimidazole（CDI） to form an activated amide intermediate 2-（benzoacridin）ethyl-imidazole-1-carboxylate（BAEIC）.BAEIC,which is dual-sensitive probe,reacts preferably with amino compounds at 80 ℃ in the presence of 4-dimethylaminopyridine（DMAP） catalyst in N,N-dimethylformamide（DMF） solvent to give the corresponding sensitively fluorescent derivatives with an excitation maximum at λex of 280 nm and an emission maximum at λem of 510 nm.BAEIC-amine derivatives simultaneously exhibited high ionization potential with percent ionization （changing from 5.62% to 58.08% in aqueous acetonitrile and from 2.14% to 56.58% in aqueous methanol.Derivatives were not only sensitive to fluorescence but also to MS ionizable potential.The fluorescence detection limits（S/N=3） were 0.12-0.59 μg/L.The online APCI-MS detection limits were 1.9-14 μg/L（S/N=5）.