Gas Chromatographic Separation of Docosenoic Acid Positional Isomers on an SLB-IL100 Ionic Liquid Column

Quantitative Analysis of the Distribution of<i> cis</i>-Eicosenoic Acid Positional Isomers in Marine Fishes from the Indian Ocean

“…The occurrence of the c7-20:1 isomer may be less documented in previous studies as this isomer overlaps with the c9-20:1 isomer in most of the GC columns that are used in the analysis of FA composition of fish lipids 10 . It was reported that c7-20:1 was a minor component in the total c-20:1 content of most pelagic fish, which is rich in either c11 or c9-20:1 isomers.…”

“…The official method by the AOCS for the determination of the isomeric profile of food uses gas chromatography GC fitted with the 100 m SP-2560 or CP-Sil 88 capillary column, operated at 180 isothermally 9 . However, some positional isomers of c-20:1 found in fish oils are not clearly separated from each other, even on the 100 m long capillary column with a cyanopropyl siloxane phase 8,10 . Furthermore, c5, c7, c9, and c11 positional isomers of 20:1 elute as a single peak on polyethylene glycol-coated columns, such as Omegawax 320 and FAMEWAX GC columns, which are commonly used for FA analysis in fish oil 10 .…”

“…However, some positional isomers of c-20:1 found in fish oils are not clearly separated from each other, even on the 100 m long capillary column with a cyanopropyl siloxane phase 8,10 . Furthermore, c5, c7, c9, and c11 positional isomers of 20:1 elute as a single peak on polyethylene glycol-coated columns, such as Omegawax 320 and FAMEWAX GC columns, which are commonly used for FA analysis in fish oil 10 . Recent application of the ionic liquid IL stationary phase imparts more polar functionalities to the capillary GC columns 11 , thus forming a useful tool in the identification of positional and geometric isomers of FAs in food.…”

“…In these studies, c-20:1 positional isomer was separated from flathead flounder and used as a reference 14 . Nakamura et al reported the distribution of c-20:1 in the lipids of 38 species, including Japanese pelagic fish, benthic fish, shellfish, and crustaceans 10,14,15 . To date, no research has been conducted on the distribution of positional isomers of LCMUFAs in fishes from the Indian Ocean.…”

Comparison of the Effects of Long-chain Monounsaturated Fatty Acid Positional Isomers on Lipid Metabolism in 3T3-L1 Cells

“…Distribution of 13 isomers of c-18:1 in dietary fats and oils, with double bond positions from ∆4 to ∆16, have been reported by researchers 6 . Furthermore, six PIs of c-20:1 and five of c-22:1 were reported in marine fish lipids 7,8 .…”