出版社：American Society for Biochemistry and Molecular Biology
摘要：Wax esters extracted from human hair have been examined by capillaryGC-MS and by nano electrospray ionization (ESI) mass spectrometryusing a tandem quadrupole mass spectrometer. Initially, thewax esters were examined by capillary GC-MS using conventionalmeans, thus revealing an incomplete chromatographic resolutionof the complex array of >200 wax esters ranging from 28 to40 carbons in length, including saturated/straight-chained,unsaturated/straight-chained, saturated/branched, and unsaturated/branchedmolecular species. ESI of wax esters produced ammonium adductions [M+NH4]+, and collisional activation of these ions formedabundant [RCO2H2]+ product ions. Wax esters containing a doublebond in the fatty acyl or fatty alcohol portion of the moleculerevealed identical behavior, suggesting little influence ofthe double bond on the ionization process or subsequent decomposition.The wax ester mixture was analyzed by ESI and tandem mass spectrometryusing multiple reaction monitoring and neutral loss scanning.The neutral loss experiment [loss of NH3 and CH2=CH-(CH2)nCH3]was particularly effective at rapidly surveying the complexbiological mixture, identifying >160 different wax estersthat range from 24 to 42 total carbons.Supplementary key words electrospray ionization • tandem mass spectrometry • gas chromatography-mass spectrometry • human hair lipids
