单糖衍生物的电喷雾质谱裂解规律研究

以1-(2-萘基)-3-甲基-5-吡唑啉酮(NMP)作单糖标识剂, 经在线串联的LC-ESI-MS建立了单糖衍生物的电喷雾质谱裂解方法.衍生物在质谱裂解中糖类化合物特有的规范信息.借助糖类化合物在ESI-MS条件下表现出的分子离子峰m/z [M H] , 及在ESI-MS/MS条件下呈现出的特征碎片离子峰m/z 473, 可有效地确定出单糖类化合物的组成. 尽管一些脂肪醛和芳香醛也能同时被标识, 然而在质谱条件下不产生m/z 473的特征碎片离子峰, 且它们的洗脱远在糖类组分之后, 因此不干扰糖类化合物的分离和结构确定.通过建立的LC-ESI-MS方法, 对水解蜂花粉中的单糖进行了分析.结果表明: 水解的蜂花粉中含甘露糖(Man)、半乳糖醛酸(GalUA)、葡萄糖醛酸(GlcUA)、鼠李糖(Rha)、葡萄糖 (Glc)、半乳糖(Gal)、阿拉伯糖(Ara)、木糖(Xyl)和岩藻糖(Fuc).本方法为环境样品中单糖类化合物的确定提供了准确、可靠的技术手段.

Cleavage Information of Mono-Saccharide Derivatives with Electrospray Mass Spectrometry

Studies on the MS cleavage information of mono-carbohydrate derivatives using the labeling reagent 1-(2-naphthyl)-3-methyl-5-pyrazolone(NMP) coupled with liquid chromatography/electrospray ionization mass spectrometry(LC-ESI-MS) are reported.Carbohydrate derivatives show sufficient ionization information under ESI-MS in positive-ion mode.An intense protonated molecular ion at m/z [M H] and characteristic fragment ion at m/z 473.0 can be used for the accurately qualitative analysis of carbohydrates.No interferences for all aliphatic and aromatic aldehydes presented in natural environmental samples were observed due to the highly specific parent mass-to-charge ratio and the characteristic fragment ions.The results from ESI-MS experiments,especially involving the characteristic fragment ions for the accurately qualitative analysis of carbohydrate derivatives,were emphasized.The carbohydrates from the hydrolyzed rape bee pollen sample including mannose,galacturonic acid,glucuronic acid,rhamnose,glucose,galactose,xylose,arabinose and fucose can successfully be identified.It will be possible to develop a promising ESI-MS technique for carbohydrate analysis.The developed method for the identification of carbohydrate compositions is very accurate and reliable.