Carbon dioxide and nitrogen were 99.95% (w/w) purity, bone dry and obtained from Praxair Canada Inc. (Mississauga, ON). Canola oil (No Name®, 100% pure) was bought from a local supermarket. β-Carotene (≥97% UV purity) and lutein (∼70% UV purity) were from Sigma Chemical Co. (St. Louis, MO). Hexane, acetone, methanol, dichloromethane, and acetonitrile were all HPLC grade and were obtained from Fisher Scientific (Fair lawn, NJ) along with petroleum ether and anhydrous sodium sulphate.