Ion chromatographic determination of nitrate and nitrite in meat products

Nitrate and nitrite are usually added to processed meat products to provide protection against microorganisms that cause food poisoning. Nitrite may react with secondary amines to form nitrosoamines, a class of carcinogens. Nitrate, although it is more stable than nitrite, can act as a reservoir for nitrite. Thus, both nitrate and nitrite need to be monitored to ensure the quality and safety of meat products. In this paper, an accurate and sensitive method is described by which nitrate and nitrite are extracted from food samples, then analyzed by ion chromatography (IC). Commercial samples of ham and salami were analyzed by IC with UV absorbance detection. UV absorbance was specific for nitrate and nitrite, eliminating interference from other ions present at much higher concentrations. Recoveries of nitrate and nitrite were greater than 90%. The method was linear (r2 > 0.999) over the working range, and detection limits for nitrate and nitrite were 50 micrograms/l and 30 micrograms/l, respectively.