Spectrophotometric determination of cobalt (II)‎ with mordant blue 9-application to vitamin B12 (injections and powder)‎

الملخص EN

A spectrophotometric method has been developed for determination of cobalt with Mordant Blue 9 in presence of cetyltrimethylammonium bromide (CTAB) in order to form an intense violetcolored chelate which exhibits maximum absorption at 586 nm at pH 3.

Beer’s law is obeyed over the range of 0.004 -1 ppm with a molar absorptivity 3.97×104 l.mol-1.cm-1, Sandell’s sensitivity index of 1.484 ng.cm-2, while LOD (limit of dedication), LOQ (limit of quantitation) are found to be 4.006 ng/ml (n=10) and 13.353 ng/ml (n=10), respectively.

The method has been applied for determination of Co(II) in pharmaceutical preparations.