Capillary electrophoresis method development for quantifying carotenoid content in the crustacean mysis diluviana

Mysis diluviana is a shrimp-like crustacean that lives in many Canadian lakes and is an important food for fish. Species of Mysis contain carotenoids which are a category of pigmented organic compounds produced mainly by bacteria, algae, and plants. Mysis obtain carotenoids through the food chain, which results in some carotenoids ending up in the tissues of predatory fish, such as trout and salmon, which feed on Mysis. Carotenoids are also responsible for the orange-red coloration in the muscle tissue of trout and salmon. Carotenoids also play a significant role in animals such as antioxidants, precursors in the production of vitamin A, and photo-inhibitory molecules. This research aimed to develop a novel capillary electrophoresis (CE) method using an aqueous buffer to detect and quantify astaxanthin, β-carotene, canthaxanthin, and lutein in M. diluviana samples. CE was the chosen analytical method for the identification and quantification of carotenoids due to its high resolution, small sample volumes, and small solvent consumption. A capillary electrophoresis method called micellar electrokinetic chromatography (MEKC) was chosen given its extended functionality with neutral analytes. To develop this novel method, the pH, concentration of sodium dodecyl sulfate (SDS), and concentration of borate were optimized in the aqueous buffer. The optimal conditions were determined to be pH 9.0, 20 mM SDS, and 60 mM borate. The wavelength of analysis was also optimized and determined to be 254nm. Also, 30% acetonitrile was able to separate the carotenoids into three peaks. The optimized method was then applied to M. diluviana samples where the solvent and extraction time was optimized for the carotenoid extraction procedure. Further optimization is required for the extraction process. It was determined that the sample extracts contained 67.25 ppm astaxanthin, 24.37 ppm β-carotene, and 13.50 ppm. Lutein was not detected in the Mysis samples.