title: Determination of vitamin B12 in dry feeds by atomic absorption spectrophotometry.
abstract: Vitamin B12 was determined in dry feeds by atomic absorption spectrophotometry (AAS). Samples containing B12 were extracted with an assay solution, 5 g EDTA was added to the filtrate, the pH was adjusted to 7 with NH4OH, and 5 g charcoal was added. The charcoal was removed by filtering through ashless paper which was then placed in a beaker and ashed at 600 degrees C. After dissolving the cobalt oxide from the ash in 5N HNO3, cobalt content was determined by using AAS. To determine mg B12/lb feed, ppm cobalt in the feed is multiplied by 10.43. The sensitivity of the proposed procedure is 1 mg vitamin B12/lb. The procedure is rapid and precise, and results compare favorably with AOAC method 43.109.
mesh_terms: D000821:Animal Feed / Q000032:analysis*; D008722:Methods; D013054:Spectrophotometry, Atomic; D014805:Vitamin B 12 / Q000032:analysis*
chemical_list: D014805:Vitamin B 12