Research Article

Comparison of Electrospray Ionization and Atmospheric Chemical Ionization Coupled with the Liquid Chromatography-Tandem Mass Spectrometry for the Analysis of Cholesteryl Esters

Table 1

Time-scheduled SIM conditions, ions and corresponding structures used in the LC-ESI-MS/MS analysis of CEs.

CompoundRetention time (RT, min)Molecular weight (Mw) SRM transitions
() Precursor ion → Product ion
Coll. energy (v)Corresponding structureNLFatty acid
ESIAPCIESIAPCIESIAPCIESIAPCI

Chl-butyrate7.02456.8479.4 → 119457.5 → 105.204062M+Na]+M+H]+2.82E + 031.22E + 024:0
479.4 → 369457.5 → 36957

Chl-valerate7.69470.8493.4 → 105471 → 3693920M+Na]+M+H]+8.14E + 039.54E + 015:0
493.4 → 3699

Chl-heptanoate8.93498.8521.4 → 147499.6 → 369318M+Na]+M+H]+1.28E + 041.14E + 017:0
521.4 → 3699

Chl-caprylate9.77512.8535.5 → 147514 → 3692210M+Na]+M+H]+1.44E + 042.94E + 018:0
535.5 → 36913

Chl-nonanoate10.64526.9549.5 → 105528 → 369425M+Na]+M+H]+1.24E + 046.03E + 019:0
549.5 → 36910

Chl-caprate11.64540.9563.5 → 107542 → 3693011M+Na]+M+H]+1.50E + 042.88E + 0210:0
563.5 → 36918

Chl-undecanoate12.51555577.5 → 161556 → 369328M+Na]+M+H]+1.76E + 043.42E + 0211:0
577.5 → 36914

Chl-laurate13.68569591.5 → 161570 → 146.93232M+Na]+M+H]+1.50E + 041.40E + 0312:0
591.5 → 369570 → 3691310

Chl-arachidonate13.98673.11690.6 → 109674 → 147.144336M+NH4]+M+H]+5.03E + 052.46E + 0420:4
690.6 → 369674 → 3691014

Chl-tridecanoate15.09583605.5 → 105584 → 3694610M+Na]+M+H]+1.22E + 041.96E + 0213:0
605.5 → 36913

Chl-linoleate15.55649.08666.6 → 161650 → 373.263015M+NH4]+M+H]+2.77E + 051.14E + 0418:2
666.6 → 369650 → 361.26915

Chl-palmitelaidate15.92623.05640.6 → 108624 → 335.213515M+NH4]+M+H]+6.73E + 044.10E + 0316:2
640.6 → 369624 → 369913

Chl-myristate16.06597619.5 → 108598 → 3693914M+Na]+M+H]+1.57E + 042.61E + 0214:0
619.5 → 36916

Chl-pentadecanoate17.52611.1633.6 → 369612 → 369125M+Na]+M+H]+5.06E + 031.75E + 0315:0

Chl-oleate18.13651.1668.6 → 147652 → 363.283320M+NH4]+M+H]+1.62E + 058.79E + 0318:1
668.6 → 369652 → 369811

Chl-palmitate18.6625.1647.6 → 147626 → 161.12823M+Na]+M+H]+1.17E + 042.23E + 0316:0
647.6 → 369626 → 3691411

Chl-heptadecanoate19.92639.1661.6 → 105640 → 146.896932M+Na]+M+H]+1.43E + 041.67E + 0317:0
661.6 → 369640 → 3691610

Chl-stearate21.31653.1675.6 → 135654 → 273.163831M+Na]+M+H]+9.78E + 037.03E + 0218:0
675.6 → 369654 → 369156

Chl-nonadecanoate22.53667.2689.6 → 119668 → 1474528M+Na]+M+H]+1.24E + 047.3419:0
689.6 → 369668 → 369199

Chl-arachidate23.85681.2703.6 → 335682 → 228.751633M+Na]+M+H]+7.32E + 046.00E + 0220:0
703.6 → 369682 → 369155

Chl-heneicosanoate25.14695.2717.7 → 349.5696 → 272.61731M+Na]+M+H]+5.94E + 042.92E + 0321:0
717.7 → 369696 → 3691914

Chl-behenate26.39709.2731.7 → 363710 → 386.131714M+Na]+M+H]+6.73E + 041.82E + 0322:0
731.7 → 369710 → 369239

Chl-lignocerate28.49737.3754.7 → 132738 → 108.965028M+NH4]+M+H]+4.86E + 045.01E + 0324:0
754.7 → 369738 → 3691116