The determination of niacin in cereals, meat and selected foods by capillary electrophoresis and high performance liquid chromatography

A robust method for the determination of niacin in cereals, meat, fish, yeast, selected nuts, peanut butter, sunflower seeds and other fortified foods using capillary electrophoresis (CE) as the determinative step is described. Niacin is liberated from the food matrix by alkaline digestion with aqueous calcium hydroxide and the extract purified and concentrated using C18 and cation exchange columns. A 75 μm uncoated fused silica capillary column with an effective length of 50 cm and a buffer comprising 15% acetonitrile and 85% of a 1:1 mixture of 0.02 m potassium dihydrogen orthophosphate and 0.02 m disodium hydrogen orthophosphate pH 7 was used for all of the determinations. Saccharin was used as the internal standard. The levels of niacin determined by CE compared favourably with those determined by high performance liquid chromatography. The CE instrument repeatability data for area calculation (CV 1%, n = 7) and migration time variation (CV 0.7%, n = 20) for a cereal sample were acceptable. The limit of reporting for the determination is 0.5 mg 100 gr−1.