Highly sensitive determination of fatty acid esters of hydroxyl fatty acids by liquid chromatography-mass spectrometry

摘要: Recently, a new class of endogenous lipids, branched fatty acid esters hydroxy acids (FAHFAs), was discovered with anti-diabetic and anti-inflammatory effects in mammals. FAHFAs attracted increasing attention because their critical physiological function. However, accurate quantitation is still challenge due to high structure similarity low abundance biological samples. Herein, we developed highly sensitive method for the determination 16 (PAHSAs, OAHSAs, SAHSAs POHSAs) samples by coupling strong anion exchange solid phase extraction (SAX-SPE) chemical labeling assisted ultra-high performance liquid chromatography/mass spectrometry (SAX-SPE-CL-UHPLC/MS). In method, SAX-SPE employed selectively enrich purify from And then pair isotope reagents, 2-dimethylaminoethylamine (DMED) d4-DMED were used label purified standard FAHFAs, respectively. The labeled mixed further subjected UHPLC/MS analysis. Our results demonstrated that detection sensitivities increased 7-72 folds upon DMED limits detections (LODs) ranged 0.01 0.14pg. Moreover, good separation isomers achieved on C18 column UHPLC system all could be analyzed 20min sharp peak shape. established provided substantial sensitivity, specificity, broad linear dynamic range (3 orders magnitude). Using this successfully measured contents distribution rat white adipose, lung, kidney, thymus, liver heart tissues. showed 7 (13-, 12-, 9-, 5-PAHSA, 13-, 12- 9-SAHSA) observed different tissues rat. addition, detected above human serum samples; among 9-PAHSA, 13- 12-SAHSA found remarkably decreased breast cancer serum. proposed applied various samples, which will facilitate understanding functions FAHFAs.