紫外分光光度法测定蔬菜硝酸盐含量

以硝酸盐含量差别很大的两种蔬菜(苦瓜和芥菜)为材料，采用硼砂、亚铁氰化钾、乙酸锌、活性碳粉制备待测液，有效地去除了有机物质的干扰。进而用紫外光度法直接测定待测液中的N03。苦瓜和芥菜N03测定结果的变异系数分别为0．9％和1．3％，回收率分别为97．1％、105．7％，平均回收率101．4％。

Determination of Nitrate Content in Vegetables by UV-Spectrophotometric Method

Balsam pear and mustard, which differ greatly in the content of nitrate, were used as test materials, hot water, borax, potassium ferrocyanide, zinc acetate, and activated carbon powder were adopted to make extract, and then UV-spectrophotometric method was used to determine the nitrate content in the extract directly. According to the determination results, the variation of nitrate in balsam pear and mustard were 0.9% and 1.3% respectively, the recovery were 71.1% and 105.7% respectively, and the average recovery was 104.1%. The test shows that UV-spectrophotometric method is simple, rapid and credible, thus applicable to the analysis of N03 in vegetables.