Comparison of Electrospray Ionization and Atmospheric Chemical Ionization Coupled with the Liquid Chromatography-Tandem Mass Spectrometry for the Analysis of Cholesteryl Esters
Comparison of Electrospray Ionization and Atmospheric Chemical Ionization Coupled with the Liquid Chromatography-Tandem Mass Spectrometry for the Analysis of Cholesteryl Esters
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DOI：
10.1155/2015/650927
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发表时间：
2015-01-01
影响因子：
1.8
通讯作者：
Shim, Soon-Mi
中科院分区：
文献类型：
--
作者：
Lee, Hae-Rim;Kochhar, Sunil;Shim, Soon-Mi
采用电喷雾电离法（ESI）和常压化学电离法（APCI）结合液相色谱-串联质谱法（LC-MS/MS）对胆固醇酯（CEs）进行了分析。比较ESI和APCI对ce的保留时间、信号强度、质子化离子和产物离子的影响。两种电离态ce的RT随双键的增加而减小，随碳链长度的增加而增大。ESI过程产生的[M+Na]（+）和[M+NH4]（+）前体离子的信号强度较强，与ce中碳链和双键的数量无关。另一方面，APCI过程产生的ce [M+H]（+）质子化离子信号强度较弱，对不饱和脂肪酸的ce前体离子检测具有选择性敏感性。结果表明，ESI技术比APCI技术更能有效地电离更多种类的ce。
The approach of two different ionization techniques including electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI) coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS) was tested for the analysis of cholesteryl esters (CEs). The retention time (RT), signal intensity, protonated ion, and product ion of CEs were compared between ESI and APCI. RT of CEs from both ionizations decreased with increasing double bonds, while it increased with longer carbon chain length. The ESI process generated strong signal intensity of precursor ions corresponding to [M+Na](+) and [M+NH4](+) regardless of the number of carbon chains and double bonds in CEs. On the other hand, the APCI process produced a protonated ion of CEs [M+H](+) with a weak signal intensity, and it is selectively sensitive to detect precursor ions of CEs with unsaturated fatty acids. The ESI technique proved to be effective in ionizing more kinds of CEs than the APCI technique.