Abstract:

Objective To evaluate the performance of stripping voltammetry for urinary iodine determination.Methods The trueness, precision, linear, cross-contamination and detection limit were analyzed by measuring human urinary freeze-dried powder and urine samples by stripping voltammetry using SR-I-100 microelement analyzer for urinary iodine, and the results were compared with those of arsenic cerium catalytic spectrophotometry. Results By stripping voltammetry, the biases of human urinary freeze-dried powders in low and high urinary iodine levels(104 μg/L and 486 μg/L)were -1.76% and 3.62%. The coefficients of variation (CV) for low, medium and high levels of urine samples (80.89 μg/L, 210.33 μg/L and 538.50 μg/L) were 9.81%, 4.27% and 3.64%. When the linear range was 100-540 μg/L, the equation of linear regression was Y=88.525X-6.678 0, R²=0.993 1.There was no cross-contamination.The lowest detection limit was 50μg/L. The CV was 12.85%. Between arsenic cerium catalytic spectrophotometry and stripping voltammetry, there was no statistical significance (P>0.05), and the correlation was good(R²= 0.97). Conclusions The stripping voltammetry has good trueness, precision, linear and detection limit without cross-contamination,and is suitable for clinical application.

Key words: Stripping voltammetry, Iodine, Urine, Chip-sensor, Arsenic cerium catalytic spectrophotometry