Automated flow-injection spectrophotometric determination of nitrosamines in solid food samples

A spectrophotometric method using a flow-injection system is proposed for t he determination of nitrosamines in foods (cured-meats). The method is base d on the photochemical cleavage of the N-NO bond of the nitrosamine to yiel d the corresponding amine and nitrite. The nitrite is then detected spectro photometrically, at 542 nm, by use of its reaction with a modified Griess r eagent. Different linear ranges between 0.8 and 2000 ng mL(-1) are obtained for the method, depending on the time of exposure of the sample to the UV radiation. The relative standard deviation varies between 2.0 and 3.9% and the sample throughput is between three and seven samples per hour, dependin g on the experimental conditions. The proposed method was successfully appl ied to the analysis of N-nitrosodimethylamine in cured ham and loin, bacon, and sausages.