Mass spectrometric profiling of saturated fatty acid esters of steroids separated by high-temperature gas chromatography.
An efficient analytical method for simultaneous determination of 12 SFEs in serum is described. The method involves solid-phase extraction to isolate of SFEs from interfering species, especially cholesteryl esters, conversion to trimethylsilyl (TMS) ether derivatives for the direct analysis by gas chromatography-mass spectrometry (GC-MS) using a high temperature MXT-1 (Silcosteel-treated stainless steel) capillary column. All SFEs as their TMS derivatives were well separated with excellent peak shapes within 12 min. Overall recoveries ranged from 88% to 119%, with a detection limits for SFEs ranged from 2 to 30 microg L(-1). The linearity as correlation coefficient was higher than 0.99 except for pregnenolone-3-arachidate (r(2)=0.98) in the concentration range of 5-3000 microg L(-1). Ten serum samples obtained from volunteers were also analyzed and quantitatively determined of DHEA-3-palmitate and pregnenolone-3-stearate in 1.8-1195.8 microg L(-1) concentration. The devised high temperature GC-MS method could be useful for identification of SFEs in biological specimens including serum.
Jung
Hyun-Jin
HJ
Life Sciences Division, Korea Institute of Science and Technology, 39-1 Hawolkok-dong, Seongbuk-ku, Seoul 136-791, South Korea.
Lee
Won-Yong
WY
Chung
Bong Chul
BC
Choi
Man Ho
MH
D004952:Esters / Q000032:analysis* / Q000097:blood / Q000138:chemical synthesis; D005227:Fatty Acids / Q000032:analysis*; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D052616:Solid Phase Extraction / Q000379:methods; D013256:Steroids / Q000032:analysis*; D013696:Temperature
D004952:Esters; D005227:Fatty Acids; D013256:Steroids