Abstract
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 violet-colored 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.
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