Determination of serum iodine by inductively coupled plasma mass spectrometry

Abstract

Objective To determine serum iodine by inductively coupled plasma mass spectrometry (ICP-MS). Methods ICP-MS was used to determine iodine content directly by pretreatment method of diluting serum samples and standard series with diluent. The method was tested from correlation coefficient of standard curve, detection limit, precision, accuracy, etc. Results When the concentration of iodine in serum ranged from 0 to 300 μg/L, the linear correlation coefficient with the iodine ion counts determined by the instrument was 0.999 8 to 1.000 0 (n= 6); the detection limit of iodine in serum was 1.24 μg/L; the relative standard deviation (RSD) ranged from 0.5% to 1.5% and from 0.3% to 1.4% for the intra-and inter-batch precision tests of seven different serum samples, respectively; the recovery rate of 7 serum samples with iodine content 40- 230 μg/L ranged from 93.4% to 109.2%, and the total average recovery rate was 102.4%. Conclusions Serum samples need not be pretreated before digestion, and can be directly injected after dilution with diluent without using highly toxic substances. The detection process is automatic, sensitive, precise, accurate and suitable for rapid quantitative determination of serum iodine content. Key words: Serology; Iodine; Inductively coupled plasma mass spectrometry; Test research