Fatty Acid Methyl Ester (FAME) Composition in Fish Oil by Capillary GC

The health benefits of fish oil in one's diet has been widely established. Common edible fish sources include salmon, trout, tuna, swordfish, and others. The omega-3 fatty acids, EPA and DHA, in dietary supplements (capsules) are primarily derived from smaller oily fish, notably anchovy, horse mackerel, bunker, capelin, and sand eel. These fish offer very little or no demand to normal human consumption. Fish oil from these sources is processed into fish meal, a cooked, dried, and milled material, which is then pressed and refined.

Chromatogram courtesy of Terje Aasoldsen, SAMSI AS, Langesund, 3970 Norway.

Fish oil capsules have become one of the major cornerstones of the nutritional supplement industry. Health benefits include the regulation of cholesterols (LDL and HDL) and triglycerides, as well as aiding in diabetes, blood pressure, and coronary heart disease. Analytical quality control of fish oil ensures the product reaching the market is unadulterated and has not oxidized.

Method used both as area % method and mg/g method as in European Pharmacopeia 2.4.22 and AOCS CE 1-89 and other pertinent collections.

Discrimination and contamination or breakdown of the long chain polyunsaturated fatty acids is the biggest challenge during the analysis. The official methodology is quite clear on its requirements to document separation and injection effects. What follows is the results of the chromatographic method shown.

Analytical Method

Injector temperature: 250 °C

Splitless time: 0.5 min

Carrier gas: 22 psi Helium

Column: 007-CW (bonded polyethylene glycol, USP G-16) 25 m × 0.25 mm i.d. × 0.20 µm film (Quadrex Corp. Woodbridge, CT)

Oven program: 90 °C (2 min hold) - 30 °C/min to 150 °C (3 °C/min) to 225 °C (6 min hold)

Flame Ionization Detector: 270 °C

Standard: Nu Check Prep 68D, (Nu-Check, Elysian, MN)

Quadrex Corporation

P.O. Box 3881, Woodbridge, CT 06525 USA

tel. (203) 393-3112, fax (203) 393-0391

Website: www.quadrexcorp.com