Determination of iodine content of iodine-rich herbal and analysis of effective factors
摘要
Objective To determine the iodine content of iodine-rich herbal and analyze the effective factors. Methods Iodine contents of seaweed at different alkali ashing temperature,such as 200 ℃,300 ℃,400 ℃,500 ℃ and 600 ℃ were determined,then the optimum ashing temperature were selected. Mixed ashing auxiliary including potassium carbonate,zinc sulfate,sodium chloride,potassium chlorate were added in samples of iodine-rich herbal,and ashed at the optimum ashing temperature for 2h. The ash was dissolved in deionized water. Iodine content of iodine-rich herbal was determined with As3 +-Ce4 +catalytic spectrophotometry. Results The optimum ashing temperature was 300 ℃; the standard curve regression equation:A =-6. 91 × 10-3C + 1. 0306,r = 0. 999 3; iodine content of seaweed,Kunbu and Haidai was 0. 829 mg /g,0. 343 mg /g and 0. 864 mg /g respectively; recovery rates before ashing of seaweed,Haidai and Kunbu were 83. 19%,81. 47% and 80. 32% respectively; 91. 24%,93. 43% and95. 86% after ashing. Conclusion Iodine is rich in iodine-rich herbal,the optimum ashing temperature is 300 ℃,and As3 +-Ce4 +catalytic spectrophotometry is stable and accurate as a determination method of iodine content of herbal.