A catalytic spectrophotometry for measuring iodine content in a small volume of urine samples with low cost of arsenic and cerium / 中华地方病学杂志

ABSTRACT

Objective To introduce a new economical method which can be used for determination of urinary iodine of batch samples with low cost of arsenic trioxide,and decrease environmental pollution.Methods A catalytic spectrophotometry for measuring iodine content in a small volume of urine samples with low cost of arsenic and cerium was established based on the principle of ammonium persulfate digestion As3+-Ce4+ catalytic spectrophotometry.Ninety-six well polypropylene microplate was utilized as digestion and catalysis reaction vessel,conventional laboratory oven was used as a tool to digest and heat,ice plate was used to cool,and the absorbance was read with the Multimode Reader.The accuracy of the new method was evaluated with the current standard method (WS/T 107-2006) by simultaneous determination of urinary iodine of 24 urine samples.Results The linear range of this method was 0-300 μg/L,the linear correlative coefficient (r) was higher than 0.999,and the detection limit was 8.67 μg/L.The coefficient of variations was 2.15％,4.33％ and 3.48％ when measuring urine samples with high,medium and low iodine concentration,respectively.The test results of three national standard urinary iodine samples were all within the given value range and the relative deviation (RD) was-0.16％,1.81％ and-2.82％,respectively.The average recovery of the low concentration was 97.51％,and that of the high concentration was 96.01％.The two methods correlated well (r =0.995,P ＜ 0.01).Conclusions This method greatly reduces the arsenic waste,environmental pollution,consumables and labor.The new method is simple and efficient,accurate and reliable;it is suitable for application as a supplementary method for analyzing urinary iodine of a large number of samples.