Abstract:

Objective To establish a wide-range detection method for urinary iodine using an automatic iodine analyzer，screen suitable parameters，and verify the reliability of the results for iodine content determination in urine. Methods The iodine content in urine within the range of 0-600 μg/L was detected using an automatic iodine analyzer.Through screening experimental parameters and verification，the characteristic parameters of the method were confirmed，and the new method was compared with the industry standard method. Results The linear range of this method was 0-600 μg/L，with a correlation coefficient r of 0.999 9-1.000 0，showing a good linear relationship. The detection limit was 1.89 μg/L，the recovery rates of low，medium，and high concentrations were 97.66%-102.84%，93.75%-99.76%，and 96.19%-102.21%，respectively. The coefficient of variation of precision for low，medium，and high concentration samples was 2.88%，2.15%，and 0.34% respectively，meeting the requirements of methodological evaluation.The new method and the industry standard method were used to simultaneously detect 25 urine samples，and there was no statistically significant difference between the two groups in the results（t=0.640，P>0.05）. Conclusion The wide-range detection method established for the automatic iodine analyzer has a linear range of 0-600 μg/L，which is wider than the 0-300 μg/L linear range of the industry standard method. This method reduces the rate of retesting，uses relatively less reagents，and achieves automation of samples，reagents，and detection，significantly improving the detection efficiency，and is suitable for large-scale urine iodine sample detection.

Key words: Urinary iodine, Automatic iodine analyzer, Wide-range, Method validation