determination of nitrite in food samples by kinetic spectrophotometric data and multivariate curve resolution-alternating least squares (mcr-als)

Herein, a method for spectrophotometric determination of nitrite in food samples with complex matrices is developed. the method is based on the standard addition and collecting kinetic data of the reaction of nitrite with 4-amino-3-hydroxynaphthalene-1-sulfonic acid (ahnsa) and 1-naphthylamine. standard additions were made based on the linear range of the method using the above reagents. kinetic data of different standard additions were augmented and subsequently analyzed by multivariate curve resolution-alternating least squares (mcr-als) to achieve second-order advantage. the proposed method was applied to real samples, and 19.86, 19.68, 1.38, 2.50, and 4.00 mg kg−1 of nitrite was found in cheese, tomato paste, sausage, hamburger, and kielbasa, respectively. the results were validated by a standard method.