Methodological evaluation on determination of low and medium concentrations water iodine by an automatic iodine analyzer

Objective To evaluate feasibility of a method for determining low and medium concentrations water iodine by an automatic iodine analyzer (hereinafter referred to as this method). Methods The low (0 - 10 μg/L) and medium (0 - 100 μg/L) concentrations water iodine were determined by an automatic iodine analyzer. Methodological experiments were carried out on this method, including standard curve linearity, detection limit, precision experiment, standard recovery experiment, and standard substance determination. Results The absolute values of the linear correlation coefficients of the low and medium concentrations standard curves were > 0.999 0, and the detection limits were 0.32 and 2.60 μg/L, respectively. Precision: the coefficient of variations were all below 2% (n = 18) of low, medium and high iodine concentrations water samples in the range of low and medium concentrations water iodine, and the average recovery rates were 100.7% and 101.1% (n = 6), respectively. The determination results of the water iodine standard substance GBW 09113d and GBW 09114d were (8.3 ± 0.3) and (61 ± 2) μg/L (n = 6), respectively, which were within the given standard values range. Conclusions This method has higher precision and accuracy, less reagent consumption, less time consumption, and simple operation. It is convenient for large-scale detection, and has strong applicability. Key words: Water; Iodine; Automatic iodine analyzer