Sequential injection determination of iron (II) in antianemic pharmaceutical formulations with spectrophotometric detection

A direct, rapid and selective Sequential Injection Analysis (SIA) method for determination of iron in pharmaceutical products is proposed. The method is based on monitoring the absorbance at 523 nm due to the complex formed between Fe (II) and 2,2-bipyridyl (alpha,alpha -bipyridyl) in acetate buffer at pH 4.5. Commercial formulations without turbidity were analyzed directly after appropriated dilution. The results presented good agreement with the values cited in the manufacturer's label and determined by flame atomic absorption spectrometry (FAAS). The method presented a linear dynamic range from 5.0 to 40.0 mg L-1 (r = 0.999) and a detection limit of 0.97 mg L-1, with a sampling frequency of 100 h(-1).