气相分子吸收光谱法测定酱腌菜中亚硝酸盐

Determination of nitrite in pickles by gas-phase molecular absorption spectroscopy

目的建立了一种气相分子吸收光谱法测定酱腌菜中亚硝酸盐的方法。方法酱腌菜中的亚硝酸盐用沸水浴浸提,浸提液沉淀蛋白质后定容并过滤,以柠檬酸-乙醇溶液作为还原剂,用气相分子吸收光谱测定滤液中亚硝酸盐的含量。结果亚硝酸盐在0.1~1.0 mg/L浓度范围内有良好的线性关系,相关系数大于0.999,检出限为0.6mg/kg,定量限为1.8mg/kg,加标回收率为81.3%~99.8%,相对标准偏差(relativestandard deviation, RSD)小于4.7%。结论该方法简便、快捷、有效,结果稳定性高,可用于酱腌菜中亚硝酸盐的检测。

Objective To establish a method for the determination of nitrite in pickles by gas-phase molecular absorption spectroscopy. Methods The nitrite in pickled vegetables was extracted with a boiling water bath. After the protein was precipitated in the extract, the volume was fixed and filtered. The content of nitrite in filtrate was determined by gas phase molecular absorption spectrometry with citric acid-ethanol solution as reducing agent. Results Nitrite had a good linear relationship in the range of 0.1~1.0 mg/L, and the correlation coefficient was greater than 0.999. The limit of detection was 0.6 mg/kg, the limit of quantification was 1.8 mg/kg, the recoveries were 81.3%–99.8%, and the relative standard deviations(RSD) were less than 4.7%. Conclusion This method is simple, rapid and accurate, which is suitable for the determination of nitrite in pickles.