AUTOMATED FLOW-INJECTION PHENOL RED METHOD FOR DETERMINATION OF BROMIDE AND BROMIDE SALTS IN DRUGS

The phenol red method for the determination of bromide has been automated by the flow injection analysis technique and optimized by the simplex method. Samples in the range of 1-10 mg/L can be measured with a precision better than 1% and, at a rate of 120 measurements/h, with a method detection limit of 90 .mu.g/L. Because of the short reaction time (20 s) the interferences of chloride and bicarbonate have been totally eliminated (up to 40 g/L and 10 g/L, respectively) and that of NH3 has been considerably decreased (up to 25 mg/L). The method was used for the determination of bromide in seawater, chloride reagents, and serum. The brominable monofunctional organic substances can be removed by using a resin column on line. The indirect determination of bromide salts of drugs was also examined and assays, content uniformity tests, and dissolution studies of commercial formulations were performed.