Colorimetric measurement of serum bromide with a bromate-rosaniline method.

A procedure is presented for measuring bromide in serum filtrates, after protein has been precipitated with a HCI-tungstate reagent. The bromide in the filtrate isoxidized to bromate with hypochlorite. The resulting bromate reacts with added bromide to release bromine. Bromine reacts with rosaniline to form bromorosaniline, which is measured colorimetrically. The method is specific, sensitive, and reproducible. Bilirubin and hemoglobin do not interfere appreciably with the procedure, and iodine interference is negligible if less than 80 mg is present per 100ml. Various factors affecting the sensitivity of the method have been studied. Preliminary data on the estimation of bromide in urine are also presented.