Liquid chromatographic determination of residual nitrite/nitrate in foods:NMKL collaborative study

Nitrite and nitrate are used as additives in the food industry to provide c olor and taste and to control undesirable gas and flavor production by anae robic bacteria by virtue of their antimicrobial properties. The analytical method that has been widely used to determine nitrite and nitrate involves the use of toxic cadmium. In response to a request from the Nordic Committe e on Food Analysis, a study was performed to obtain an alternative chromato graphic method to determine residual nitrite and nitrate in meat products. The study was done in 3 stages: (1) comparative evaluation of the performan ce of 3 liquid chromatographic methods, (2) internal validation of the sele cted ion chromatographic method, and (3) a collaborative study in which 17 laboratories from European countries participated. Furthermore, the applica bility of the method to matrixes other than meat and meat products was demo nstrated. The results of the collaborative study show that the European Pre standard prENV 12014-4 is well suited for the determination of nitrite and nitrate in different foods (e.g., meat products, vegetables, baby food, and cheese). The limits of detection for nitrite and nitrate ions are 1 and 10 mg/kg, respectively. Recoveries of residual nitrite/nitrate ranged from 96 to 108%, Repeatability and reproducibility were satisfactory.