Dosage du cobalt par spectrométrie d'absorption atomique et application à l'analyse de la vitamine B12

We purpose in this study to describe a method for determination of vitamin B12 based in the speciation of the metal element: cobalt. First, a method for determination of cobalt by atomic absorption spectrometry with graphite furnace atomization was evaluated.Calibration was prepared with aqueous solution is linear from 10 to 150 μg/L (correlation coefficient = 0,98); the limit of detection is about 6,8 μg/L. The precision (repeatability: 1,2 à 6,9 %) and accuracy (108 %) were acceptable. This procedure was studied in serum with the same protocol. Secondly, the method was applicated to the determination of vitamin B12 in pharmaceutical injection and in serum. Recoveries ranged from 98,5 to 100,9 % for drugs. Comparison with results obtained with the microparticule enzymatic method (MEIA Abbott®) for serums were less satisfactory.