精确质量数在单四极杆质谱定性分析农药中的应用

Application of Accurate Mass and Elemental Composition Determination for Pesticides Identification Using a Unit Mass Resolution Gas Chromatography/Mass Spectrometry

利用MassWorks软件对GC/MS采集的目标农药谱图进行校正后,实现了在单位分辨率质谱上测定6种农药化合物的精确质量数,质量误差小于0.02;在精确质量数基础上,进一步采用同位素峰形校正检索技术(CLIPs),实现了对目标农药分子式的准确识别,建立了在单位分辨率质谱上准确测定农药小分子化合物的方法,提高了单位分辨率质谱的定性能力.通过对丙草胺及哒螨灵两种农药的质谱碎片所获得的Mass-Works精确质量数及元素组成推导其质谱碎裂机理,通过对碎片的精确质量数测定可提高对目标物定性的准确性.

On a unit mass resolution mass spectrometer,such as a single quadrupole MS,allowing for only rough mass confirmation for qualitative analysis.In this study,a novel mass spectral calibration technique,MSIntegnityTM implemented in MassWorksTM,is introduced to externally calibrated using a unique procedure that corrects for both mass axis and mass spectral peak shape to facilitate pesticides identification with high mass accuracy,MS data were acquired in profile mode on a unit mass resolution single-quadrupole instrument,even at such a unit mass resolution on a true chromatographic time scale,will now enable the elemental composition determination of unknown ions or ion fragments using a conventional mass spectrometer.This identification capability is further enhanced by a uniquely accurate approach for elemental composition determination through the use of isotope distribution information,CLIPSTM.