現代の化学と応用

概要

Improvements in the High-Performance Liquid Chromatography and Extraction Conditions for the Analysis of Oxidized Fatty Acids Using a Mixed-Mode Spin Column

Takao Sanaki, Takuji Fujihara, Ryo Iwamoto, Takeshi Yoshioka*, Kenichi Higashino, Toru Nakano and Yoshito Numata

Lipidomics by liquid chromatography/mass spectrometry has been used for a better understanding of the roles of oxidized fatty acids in the development of various diseases. However, further work is required to improve the sample preparation process and the peak tailing of cysteinyl-leukotrienes. In this study, we evaluated various mobile phases and extraction conditions. The addition of phosphoric acid to the mobile phase improved the peak tailing of cysteinyl-leukotrienes. The extraction conditions were also optimized by spin-column possessing an anion-exchange and reversed-phase properties. The extraction efficiency of the modified extraction system was examined using 62 lipids, and 13 deuterated lipids were investigated to evaluate matrix effects and recovery from mouse lung homogenate samples. Extraction efficiencies of ≥70% were obtained for almost all of the lipids. Good results with standard deviations of <15% were obtained for the matrix effects and recovery. Finally, the efficiency of our extraction method was compared with those of several conventional methods, and those of leukotriene C4 was improved significantly using our method. Moreover, the proportion of variance between our method and the conventional methods was >0.99 for all the lipids tested. This newly developed method therefore represents a powerful tool to analyze lipids.