钼酸铵比色法测定蔗汁中磷酸盐含量试验方法的改进

采用钼酸铵比色法测定蔗汁中磷酸盐含量。考察检测波长、显色时间、硫酸溶液、钼酸铵溶液和氯化亚锡溶液添加量对测定结果的影响。研究结果表明:检测波长为660 nm;硫酸溶液(6.25 mol/L)、钼酸铵溶液(25 g/L)和氯化亚锡溶液(50 g/L)的加入量分别为0.5、2.0 m L、15滴;显色时间5 min。在此条件下,磷酸盐测定回归方程为A=0.17898C+0.00093,相关系数r=0.9998,线性关系良好。高、中、低3种样品浓度方法回收率和RSD都在合理范围内。该方法可用于蔗汁中磷酸盐含量测定。

Ammonium Molybdate Spectrophotometric Method for the Determination of Phosphate Content in Sugarcane Juice

Ammonium molybdate spectrophotometric method was adopted for the determination of phosphate content in sugarcane juice. We investigated detection wavelength, color development time, the amount of reaction reagents effect on the determination results. The results showed that detection wavelength was 660 nm, sulfuric acid (6.25 mol/L) amount was 0.5 mL, ammonium molybdate solution (25 g/L) amount was 2.0 mL, stannous chloride solution (50 g/L) amount was 10 drops, and color development time was 5 min. Under these conditions, the regression equation wasA=0.17898C+0.00093 (r=0.9998), which had a good linear relationship. High, medium and low samples recovery rates and RSD were all in a reasonable range. The method could be applied to the determination of phosphate content in sugarcane juice.