کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1202345 | 1493548 | 2015 | 11 صفحه PDF | دانلود رایگان |
• Fatty acid diesters of long-chain 1,2-diols were isolated from vernix caseosa.
• Molecular species were separated in RP-HPLC with acetonitrile–ethyl acetate gradient.
• Structures were elucidated using tandem mass spectrometry with MS, MS2 and MS3 steps.
• More than 2000 molecular species identified in 141 chromatographic peaks.
Fatty acid diesters of long-chain 1,2-diols (1,2-DDE), or type II wax diesters, were analyzed in the vernix caseosa of a newborn girl. 1,2-DDE were isolated from the total lipid extract by the semipreparative TLC using plates coated with silica gel. Chromatographic separation of the 1,2-DDE molecular species was achieved on the non-aqueous reversed-phase HPLC with two Nova-Pak C18 columns connected in series (a total length of 45 cm) and using an acetonitrile–ethyl acetate gradient. 1,2-DDE eluted from the column in the order of their equivalent chain number. The analytes were detected as ammonium adducts by an ion-trap mass spectrometer equipped with an atmospheric pressure chemical ionization source. Their structures were elucidated using tandem mass spectrometry with MS, MS2 and MS3 steps in a data-dependent mode. More than two thousand molecular species of 1,2-DDE were identified in 141 chromatographic peaks. The most abundant 1,2-DDE were monounsaturated lipids consisting of a C22 diol and a C18:1 fatty acid together with C16:0, C14:0 or C15:0 fatty acids. The positions of double bonds were characterized by the fragmentation of [M+C3H5N]+ formed in the ion source.
Journal: Journal of Chromatography A - Volume 1378, 23 January 2015, Pages 8–18