Abstract:

An analytical method using ion chromatography was developed for the determination of nitrate and nitrite in soybean milk powder. Samples were extracted with deionized water and cleaned up using solid phase extraction prior to ion chromatographic analysis. The linear ranges for nitrate and nitrite were 1－50 mg/L and 1－25 mg/L, respectively. The average recovery ranges for nitrate and nitrite in 3 commercial brands of soybean milk powder were 89.3% － 98.9% and 89.6% － 102.0%, respectively. The method with the limits of detection of 0.16 mg/kg for nitrate and 0.11 mg/kg for nitrite proved to have the benefits of simplicity, high sensitivity and accuracy and good reproducibility.

Key words: nitrate, nitrite, ion chromatography, solid phase extraction