ABSTRACT
Objective Establish a laboratory quality control system to ensure accurate and reliable test data and to contrapose the influence of error factors in current detection methods for urinary iodine measurement. Methods The results of reagent blank absorbance value and uric iodine standard materials were collected, then their relevant technical indexes such as mean, standard deviation, control limit, auxiliary line were worked out. Then the quality control chart of blank test and the relative error control chart were made base on these technical indexes. And different iodine concentrations (high, middle and low concentration) were tested and their mean,relative reduction difference value, weighted mean value and critical limit Rc value were calculated, and then critical limit Rc value precision control chart was made. Results The range of absorbance of blank control test was 1.183 to 1.553. And the limit of the accuracy control Rc value was 0.0883, 0.0572, respectively, when the concentrations of urinary iodine was 0～ < 150 μg/L and 150 ～ 300 μg/L. The control limit of the relative error was 9.3%. Conclusions The method of quality control chart could be satisfactorily applied to identify the quality of the analytical results of urine iodine, and ensure the results of the urine iodine reliable and authentic.