瓜子壳作为新型木质电喷雾材料的分析性能研究

Study on Analytical Properties of Sunflower Seed Husk as a New Wooden Electrospray Ionization Material

建立了一种简单经济实用的电喷雾质谱技术(ESI-MS),利用一次性前端削尖的瓜子壳承载样品,并使其离子化。采用瓜子壳蘸取样品溶液,或通过移液器将样品加入到瓜子壳的凹槽中。瓜子壳的尖端角度在60°~90°范围内,瓜子壳尖端与质谱仪入口之间的距离在2~3 mm范围内,关闭所有去溶剂化气体,在尖端施加3.5~4.0 kV高压后,可获得理想的质谱效果。实验结果表明,这种新技术适用于多种样品的分析,包括木质素、人参皂苷、氨基酸和蛋白质等。将其与传统电喷雾和牙签木尖喷雾进行对比,在检测木质素类物质和人参皂苷及蛋白质分子时,瓜子壳木尖喷雾相较于其它两种电离方式效果更佳。本方法还可分析一些不能通过传统的电喷雾技术直接分析的样品,如固体粉末样品等。在本研究中,参照ESI的单针进样方式设计了一种可连续进样的装置,利用此装置对人参粉末进行在线提取,获得持续稳定的总离子流图,并得到了十分丰富的质谱信息。

A simple and economical type of electrospray ionization(ESI)technique was developed for loading and ionization of samples by use of disposable wooden tips of sunflower seed husk.Samples could be loaded by simply dipping the tip into sample solutions or normal pipetting onto the natural groove of sunflower seed husk.Instrument parameter settings were optimized to obtain highly sensitive determination of ion intensity of samples,and full MS mode was applied to obtain the mass spectra.The wooden tip of the sunflower seed husk was pointed to the mass spectrometer inlet for Q-Orbitrap mass spectrometer,and the angles were between 60°and 90°in wooden tip.The tip was positioned 2-3 mm away from the inlet of mass spectrometer.The applied voltage to wooden tip of sunflower seed husk was adjusted in the range of 3.5-4.0 kV until optimal ion signals were obtained and all desolvation gases were turned off.The experimental results showed that this new ionization technique was applicable for analysis of various samples,e.g.lignin,ginsenoside,amino acid,proteins,etc.Comparing ESI technique and wooden tip spray coupled toothpick technique,the wooden tip spray with sunflower seed husk(WTSSSH)technique had better efficient in determination of lignin,ginsenoside and proteins by mass spectrometry.Some special sample,e.g.powder,could not be directly analyzed by ESI and wooden tip spray with toothpick,but it was convenient for WTSSSH.In this study,we established a continuous injection device based on the single needle injection method of ESI.The ginseng powder was on-line extracted with the device and the extracts was ionized in wooden tip of sunflower seed husk for mass spectrometric analysis,and a continuous and stable total ion chromatogram and abundant information of mass spectra were obtained.