质谱学报2026，Vol.47Issue(1)：58-66,9.DOI:10.7538/zpxb.2025.0051
利用全碰撞能-拟三级质谱匹配策略鉴定甘油酯
Identification of Glyceride Using Full Collision Energy Ramp-Pseudo-MS3 Spectrum Matching Strategy
摘要
Abstract
Glycerides(Glys),a class of esterification products of glycerol and fatty acids,serve as significant pathological markers for a variety of metabolic diseases.From the structural perspective,the different linkages(straight-or branched-chain),C=C bond positions,and other factors of fatty acyl chains lead to the existence of numerous isomers in Glys,and the key to achieving isomeric differentiation lies in the structural identification of the fatty acid chain.In the present research,taking a group of monoacylglycerol(Mag),diacylglycerol(Dag),and triacylglycerol(Tag)with the same fatty acyl structure as examples,a novel mass spectrometry(MS)method for identifying fatty acid chains was proposed,which was achieved by comparing the consistency of the fatty acyl chain cations generated by collision-induced dissociation(CID)of Mag,Dag,and Tag with the quasi-molecular ions of known fatty acids.Quadrupole-time-of-flight tandem MS was utilized to obtain high-resolution m/z values of precursor and fragment ions for glycerin monostearate(Gms),glycerin distearate(Gds),glycerol tristearate(Gts),stearic acid(Ste),and isostearic acid(iSte).To comprehensively record the CID behaviors of the target ions,full collision energy ramp-MS2 spectra(FCER-MS2)of Ste and iSte cations,as well as full collision energy ramp-pseudo-MS3 spectra(FCER-pseudo-MS3)of the Ste-unit cations generated by the in-source CID of Gms,Gds,and Gts,were constructed based on online energy-resolved MS.The differential fragmentation patterns of isomers were investigated by combining MS fragmentation rules and quantum chemical calculation.MS2 spectra of Ste and iSte exhibited strong similarities,characterized by a series of fragment ions with a consistent mass difference(Δ)as 14 u.However,the FCER-MS2 spectra of the two were distinguishable,such as the collision energy level corresponding to 50%survival yield(CE50)of the ion at m/z 285.3 and the optimal collision energies(OCEs)of ions at m/z 87.1,75.1,and 51.1.As expected,the FCER-pseudo-MS3 spectra of Ste-unit cations from Gms,Gds,and Gts were essentially consistent with the FCER-MS2 spectrum of Ste cation,but significantly differed from the FCER-MS2 spectrum of iSte cation.Consequently,it is feasible to identify the fatty acyl chain of Gly by comparing the FCER-pseudo-MS3 of fragment ions-of-interest with the FCER-MS2 of the candidate fatty acid ions.This approach provides a viable method for identifying structural units of other complex compounds.关键词
全碰撞能二级质谱/全碰撞能拟三级质谱/源内裂解/甘油酯/同分异构体Key words
full collision energy ramp-MS2/FCER-pseudo-MS3/in-source collision-induced dissociation/glyceride/isomers分类
化学化工引用本文复制引用
周雨萱,李菡,金慧,刘明昊,张珂,宋月林..利用全碰撞能-拟三级质谱匹配策略鉴定甘油酯[J].质谱学报,2026,47(1):58-66,9.基金项目
国家自然科学基金(82474202) （82474202）
