Evaluation of laboratory performance for iodine analysis in iodized salt

Abstract

       Salt iodization is considered as an important mechanism for providing an adequate amount of iodine to Thai population. Production of iodized salt needs to be controlled according to the regulation, therefore, analytical test results obtained from regulator’s laboratories, manufacturer’s laboratories and mobile laboratories using either Titration method, I-Reader or I-Kit are required. Thus, to assure laboratory performance on analysis of iodine content, 2 rounds of Proficiency Testing (PT) Program for iodine content in edible salt was established in 2016. The evaluation results of 1^st round showed that 94.4%, 41.4% and 68.9% of participants using iodometric titration, I-Reader and I-Kit had satisfactory results, respectively. For the 2^nd round results, it was found that 100%, 58.8% and 85.0% of participants using iodometric titration, I-Reader and I-Kit had satisfactory results, respectively. Additionally, trainings on analytical technique and quality assurance were provided for participants to ensure accuracy of analytical results that could be useful for quality control of iodized salt.