Spectrophotometric Determination of Iron(II) and Cobalt(II) by Direct, Derivative, and Simultaneous Methods Using 2-Hydroxy-1-Naphthaldehyde-p-Hydroxybenzoichydrazone

Table 13

Determination of cobalt in pharmaceutical tablets.

Sample (mg/tablet)	Amount of cobalt (μg mL^−1)
	Reported	Found*	Relative error (%)
Neurobion forte; (cyanocobalamine-15 mg)	7.45	7.4	−0.67
Basiton forte; (cyanocobalamine-15 mg)	7.42	7.24	−2.42

*Average of four determinations.