title: Methodological and analytical aspects of simple methods for measuring iodine in urine. Comparison with HPLC and Technicon Autoanalyzer II.
abstract: This work describes an optimization of a simple photometric determination of iodine concentrations in urine using a modified ceric arsenite method with ammonium persulfate as oxidant. By means of this sensitive method iodine concentrations can be determined in very small specimens (50 microL). Urine samples (105) collected from a mixed population, were analyzed for urine iodine content by the optimized ammonium persulfate method, a Technicon Autoanalyzer II and a paired-ion-RP HPLC. We found that the precision of this optimized ammonium persulfate method yields inter assay CVs of <10% for urinary iodine concentrations >10 microg/dL. Recovery of [123I]iodide added to urine in vitro was 100.9 +/- 2.4%. The detection limit was 0.0029 microg iodine. There was a high correlation between all three methods (r > 0.94 in any case) and the interpretation of the results was consistent. We conclude that this simple, manual ammonium persulfate method is suitable for urinary iodine analysis and can be performed in any routine clinical laboratory.
authors.affiliation: Klinik und Poliklinik für Nuklearmedizin der Universität Würzburg, Germany.
authors.forename: D
authors.initials: D
authors.lastname: Bier
authors.forename: J
authors.initials: J
authors.lastname: Rendl
authors.forename: M
authors.initials: M
authors.lastname: Ziemann
authors.forename: D
authors.initials: D
authors.lastname: Freystadt
authors.forename: C
authors.initials: C
authors.lastname: Reiners
mesh_terms: D000645:Ammonium Sulfate; D018053:Arsenites; D001322:Autoanalysis / Q000295:instrumentation; D002851:Chromatography, High Pressure Liquid; D003124:Colorimetry; D006801:Humans; D007454:Iodides; D007455:Iodine / Q000652:urine*; D007457:Iodine Radioisotopes; D012680:Sensitivity and Specificity; D013053:Spectrophotometry
chemical_list: D018053:Arsenites; D007454:Iodides; D007457:Iodine Radioisotopes; C031276:ammonium peroxydisulfate; D007455:Iodine; C015001:arsenite; D000645:Ammonium Sulfate