S hort C ommunication : Rapid separation of cis 9, trans 11- and trans 7,c is 9-18:2 (CLA) isomers from ruminant tissue using a 30 m SLB-IL111 ionic column

Turner, T., Rolland, D. C., Aldai, N. and Dugan, M. E. R. 2011. Short Communication: Rapid separation of cis 9, trans 11- and trans 7,c is 9-18:2 (CLA) isomers from ruminant tissue using a 30 m SLB-IL111 ionic column. Can. J. Anim. Sci. 91: 711–713. Rumenic acid (cis9,trans11-18:2) is the main natural isomer of conjugated linoleic acid (CLA). Rumenic acid has many purported health benefits, but effects of most other CLA isomers are unknown. Typically trans7,cis9-18:2 is the second most abundant CLA isomer, but it co-elutes with rumenic acid on conventional polar gas chromatography (GC) columns, requiring complimentary analysis with silver-ion high performance liquid chromatography (Ag + -HPLC). Herein we report a rapid method for analyzing rumenic acid and trans7,cis9-18:2 using a 30 m ionic-liquid GC column. Optimal resolution of the two CLA isomers was at 145°C and analysis of backfat from barley-fed cattle compared well with GC/Ag + -HPLC (y=0.978x – 0.031, r=0.985, P