Comparison of Atmospheric Pressure Photoionization, Atmospheric Pressure Chemical Ionization, and Electrospray Ionization Mass Spectrometry for Analysis of Lipids

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• 作者：Sheng-Suan Cai and Jack A. Syage
• 刊名：Analytical Chemistry
• 出版年：2006
• 出版时间：February 15, 2006
• 年：2006
• 卷：78
• 期：4
• 页码：1191 - 1199
• 全文大小：378K
• 年卷期：v.78,no.4(February 15, 2006)
• ISSN：1520-6882

文摘

In this work, we compare the quantitative accuracy andsensitivity of analyzing lipids by atmospheric pressurephotoionization (APPI), atmospheric pressure chemicalionization (APCI), and electrospray ionization (ESI) LC/MS. The target analytes include free fatty acids and theiresters, monoglyceride, diglyceride, and triglyceride. Theresults demonstrate the benefits of using LC/APPI-MS forlipid analysis. Analyses were performed on a Waters ZQLC/MS. Normal-phase solvent systems were used due tolow solubility of these compounds in aqueous reversed-phase solvent systems. By comparison, APPI offers lowerdetection limits, generally highest signal intensities, andthe highest S/N ratio. APPI is 2-4 times more sensitivethan APCI and much more sensitive than ESI withoutmobile-phase modifiers. APPI and APCI offer comparablelinear range (i.e., 4-5 decades). ESI sensitivity is dramatically enhanced by use of mobile phase modifiers (i.e.,ammonium formate or sodium acetate); however, theseESI adduct signals are less stable and either are nonlinearor have dramatically reduced linear ranges. Analysis offish oils by APPI shows significantly enhanced targetanalyte intensities in comparison with APCI and ESI.