A method for determination of urinary iodine by automatic biochemical analyzer

Objective To establish a method for determination of urinary iodine by an automatic biochemical analyzer, and to analysis the applicability on the detection of iodine deficiency disorders. Methods An automatic biochemical analyzer was used to determine urinary iodine content. Linear range, detection limit, precision, recovery and so on were studied. Results The linear range was 0-300 μg/L; the detection limit was 1.57 μg/L (600 μl sample); the relative standard deviations (RSD) were 1.30%, 0.83% and 1.05% when measuring urine samples with iodine concentrations of (84.8 ± 1.1), (156.5 ± 1.3) and (227.7 ± 2.4)μg/L, respectively; the average recovery was 98.0%, 100.1% and 98.6%, and the total average recovery was 98.9%, when measuring urine samples containing three different iodine concentrations. The test results of standard material were all within the required ranges. The difference of measuring 24 urine samples in the field by this method and the standard method was not statistically significant by paired t test (t = 0.35, P > 0.05). Compared with standard method, the amount usage of arsenic trioxide was reduced to 2% (0.50 to 25.00 mg per sample). Conclusions The method has the advantages of simple operation, low requirement for environment, and the linear rang of detection is reasonable. Using this method, the usage of highly toxic reagent can be greatly reduced, as well as the risk of harm to personnel health and the level of environment pollution. The standard solution and reagents can be prepared by ourselves, which greatly reduces the costs. With short reaction time, high detection speed and measuring automatically for large numbers of samples, this method for determination of urinary iodine by an automatic biochemical analyzer can be applied in monitoring of iodine deficiency disorders. Key words: Urine; Iodine; Arsenic; Automatic biochemical analyzer; Methods