Indirect Determination of Nitrites in Salted and Pickled Vegetables by AAS

A method for indirect determination of nitrite in salted and pickled vegetables by AAS was proposed in this paper.Nitrite was extracted from sample with distilled water,and reacted with KMnO4 to precipitate MnO2 in a H2SO4 medium of pH 3.0.The precipitate of MnO2 obtained was dissolved in 6.0 mol·L-1 H2SO4 and determined by AAS,and the amount of Mn2+ found was converted into contents of nitrite.Linear relationship between values of absorbance and mass concentration of manganese was obtained in the range of 0.10-4.0 mg·L-1.Tests for accuracy and precision were made by addition of standard solutions to sample solutions at the concentration level of 0.20 mg·g-1 and analyzed by the proposed method,values of recovery in the range of 94.5%-105.0% and values of RSD′s (n=10) less than 1.0% were obtained.