碘酸钾碘盐自然存放10年碘损失研究

目的研究碘酸钾(KIO3)碘盐稳定性.方法以40目粉碎的KIO3,用干混法生产的23份KIO3碘盐散装暴露在空气中常温常湿存放10年,用直接容量滴定法测定不同存放期碘盐的含碘量.结果存放22个月内检验碘含量14次,碘下降0.31%;存放32个月碘下降6.38%;存放36个月碘下降9.10%;存放60个月碘下降10.28%;存放84个月碘下降19.63%;存放96个月碘下降25.51%;存放108个月碘下降28.61%;存放120个月碘下降30.40%;其中36,54,60,84,96,108,120个月存放期样品均有程度不同的碘下降,碘下降率与其样品含碘量呈负相关.结论KIO3碘盐化学性质较稳定,其碘盐在商业流通周期内碘含量基本不变,10年实验结果提示,它确属国内外所推崇的长效碘盐,并证明新碘盐标准(GB5461-2000)的碘含量统一为1种标准-(35±15)mg/kg是十分正确的.

Experimental study on iodine loss in Natural Storage KIO3-iodized salts during 10 years

Objective To study the stability of KIO 3 iodized salts which were produced by dry mixed method and naturally stored between 0 and 120 months (10 years).Methods Twenty times of determination for iodine contents were conducted in 23 samples of KIO 3 iodized salts which were produced by dry mixed method through 40 aperture sieve pulverization and which were naturally stored in bulk for 10 years.Results The results showed that iodine means were basically not changed on the 22nd month,decreased 6.38% on the 32nd month,declined 9.10% on the 36th month,reduced 10.28% on the 60th month,and lowered 19.63% on the 84th month and lowered 25.51% on the 96th month,and lowered 28.61% on the 108th month,and lowerd 30.40% on the 120th month.Iodine contents in all samples stoued on the 36th,54th,60th,84th,96th,108th,120th month,were decreased in different degrees.There were a negative correlation between the rates of iodine decreasement and iodine contents in the sample.Conclusions The chemical quality of iodized salts is of stability and the contents are not changed basically in commercially circulated periods.This study has shown a criterion of qualified iodine concentration.