Spectrophotometric determination of nitrite in cured meat with sequential injection analysis

A sequential injection system for the determination of nitrite in cured meat is proposed. The meat samples are partially dissolved in a 1 mol l(-1) ammonium chloride solution at pH 9. Nitrite is coupled and diazotised in the SIA system with sulphanilamide and N-(1 -naphthyl)-ethylenediamine dihydrochloride, respectively, to form a highly coloured azo dye which is measured at 540 nm. The sample throughput is 49 samples per hour with sample volumes of 250 mu l and a relative standard deviation of <1.7%. The results obtained for nitrite in cured meat by the SI system compared well with data obtained by a standard method.