氮杂环荧光试剂2-(11H-苯[a]咔唑)乙基氯甲酸酯对胺类化合物标记及质谱鉴定

Mass Spectrometric Identification of Aliphatic Amines Using 2-(11H-Benzo[a]carbazol-11-yl)ethyl Chloroformate as Fluorescence Labeling Reagent

含氮类荧光试剂2-（11H-苯[a]咔唑）乙基氯甲酸酯（BCEC—Cl）经柱前衍生处理后，采用荧光检测及柱后在线质谱鉴定对食品中胺类化合物进行了测定。标记反应在pH9的硼酸缓冲液中进行，3min后获得稳定的荧光产物。衍生物于λex=279nm激发条件下产生强烈荧光，其发射波长在λcm=380nm处。产物的分离在Eclipse XDB—C18色谱柱（150mm×4、6mm，5μm）上进行，采用梯度洗脱对12种脂肪胺衍生物进行了优化分离。采用大气压化学电离源（APCI Source）正离子模式进行在线的柱后质谱鉴定，实现了多种脂肪胺衍生物的快速、准确测定。建立的方法具有良好的重现性，回归系数大于0．9996，检出限为1．8～14fmol。

A simple and highly sensitive method based on the pre-column derivatization for the determination of aliphatic amines in food using a nitrogen-containing 2-（ 11H-benzo [ a ] carbazol-11-yl） ethyl chloroformate （BCEC-Cl） as fluorescence labeling reagent followed by high-performance liquid chromatography with fluorescence detection has been developed. The stable derivatives can be obtained by the labeling reaction of BCEC- Cl with amines in the presence of borate buffer （ pH 9.0） within 3 rain. The maximum excitation and emission wavelengths were 279 nm of λex and 380 nm of λcm, respectively. Separation of 12 amine-derivatives was achieved by a gradient elution on a reversed-phase Eclipse XDB Cs （150 mm ×4.6 mm, 5μm） column with a good baseline resolution. The identification of amine-derivatives was carried out by the online post-column MS using atmospheric pressure chemical ionization （APCI） as ion source in positive-ion detection mode. The established method exhibits excellent reproducibility and recovery. Excellent linear responses were observed with the correlation coefficients 〉 0. 9996. The detection limits （at signal-to-noise of 3：1 were at levels 1.8 - 14 fmol.