基于超高效液相色谱-四极杆/静电场轨道阱高分辨质谱技术研究全氟化合物质谱裂解规律

Study on mass spectroscopic fragmentation pathway of perfluorinated compounds using ultra performance liquid chromatography-quadrupole/electrostatic field orbitrap high resolution mass spectrometry

目的采用超高效液相色谱-四极杆/静电场轨道阱高分辨质谱研究全氟化合物的质谱裂解规律。方法标准品由甲醇溶解并配制成混标溶液,经Thermo Hypersil GOLD aQ色谱柱(100 mm×2.1 mm,1.9μm)分离,以甲醇和0.1%甲酸水溶液为流动相进行梯度洗脱,在电喷雾负离子模式下采集数据,根据一、二级质谱离子的精确质荷比推导全氟化合物可能的裂解途径。结果全氟磺酸类化合物主要发生CC键和CS键断裂,产生特征碎片[·C3F6-SO3]–m/z229.94和[SO3]–m/z79.95;全氟羧酸类化合物首先丢失中性分子CO2,产生[M-O-CO2]–碎片离子,继而发生不同数量的CC键断裂,产生m/z218.98、168.98、118.99等特征碎片离子。结论该研究提出的质谱裂解规律为快速鉴定和分析复杂体系中具有相似结构特征的全氟化合物提供重要依据。

Objective To study the mass spectroscopic fragmentation law of perfluorinated compounds by ultra performance liquid chromatography-quadrupole/electrostatic field orbitrap high resolution mass spectrometry.Methods The standard substance was dissolved in methanol and prepared into a mixed standard solution,and separated by Thermo Hypersil GOLD aQ column(100 mm×2.1 mm,1.9μm)using methanol and 0.1%formic acid solution as mobile phase for gradient elution.The data was collected under electrospray negative ion mode,and the fragmentation pathways of perfluorinated compounds were derived by the precise mass-to-charge ratio of the first and second mass spectrometry ions.Results Perfluorosulfonic acids mainly underwent CC bond and CS bond cleavage,resulting in characteristic fragments of[·C3F6-SO3]–m/z 229.94 and[SO3]–m/z 79.95.Perfluorocarboxylic acid compounds first lost the neutral molecule CO2 and produced[M-O-CO2]–fragment ions,then different numbers of CC bonds were broken,resulting in characteristic fragment ions such as m/z 218.98,168.98,and 118.99.Conclusion The mass spectroscopic fragmentation law proposed in this study provides an important basis for the rapid identification and analysis of perfluorinated compounds with similar structural characteristics in complex systems.