Determination of iodine in water by antimony cerium catalytic spectrophotometry / 中华地方病学杂志

ABSTRACT

Objective:To establish an antimony cerium catalytic spectrophotometric method for determination of iodine in water (referred to as the new method).Methods:Using the fading reaction principle of iodine catalyzed kinetics of antimony cerium to determine the iodine content in water. Methodological evaluations were conducted on the linear relationship, quantitative detection limit, precision, and accuracy (determination of national water iodine first level standard substances GBW09113f, GBW09114f, and addition recovery experiments) of the new method within the range of 0 to 100 μg/L iodine mass concentration. And the method was compared with the determination results of water iodine by arsenic cerium catalytic spectrophotometry recommended by the national iodine reference laboratory (NRL).Results:Within the range of 0 - 100 μg/L iodine mass concentration, the curve correlation coefficient of the new method was greater, and | r| > 0.999 0, and the quantitative detection limit was 0.15 μg/L (the sampling volume was 1 ml), the relative standard deviation of the detection precision of water samples with low, medium and high iodine mass concentrations were less than 2%. The new method had determined the average values of national water iodine first level standard substances GBW09113f and GBW09114f were 8.32 and 54.54 μg/L, respectively, all within the standard value range. The recovery range of standard addition was 92.6% - 99.2%, and the total average recovery was 96.4%. Compared with the NRL recommended method, the difference was not statistically significant ( t = 0.99, P > 0.05). Conclusion:The new method does not require the use of highly toxic substance arsenic trioxide, has high reaction sensitivity and accuracy, and is suitable for the promotion and use of water iodine detection.