Kinetic determination of iodide in pharmaceutical and food samples.
A kinetic method for the determination of iodide based on its inhibitory effect on the Pd(III) catalysed reaction between ethylenediaminetetraacetic acid (EDTA)-Co(III) and the hypophosphite ion is described. The reaction was followed spectrophotometrically by measuring the decrease in the absorbance at 540 nm. Under the optimum experimental conditions of 2.6 x 10(-3) mol dm(-3)Co(III)-EDTA, 0.4 mol dm(-3)H2PO2-, pH 3.2 (adjusted with Britton-Robinson buffer), 0.57 micrograms ml(-1) Pd(III) and 20 +/- 0.2 degrees C, iodide was determined in the range 2-28 ng ml(-1). The method was applied to the determination of iodide in pharmaceutical products, iodinated salts, cow's milk and infants' powdered milk.
Garcia
M S
MS
Department of Analytical Chemistry, University of Murcia, Spain.
Sanchez-Pedreño
C
C
Albero
M I
MI
Sanchez
C
C
D000818:Animals; D004492:Edetic Acid; D005504:Food Analysis / Q000379:methods*; D006801:Humans; D007202:Indicators and Reagents; D007223:Infant; D007225:Infant Food / Q000032:analysis; D007454:Iodides / Q000032:analysis*; D007700:Kinetics; D008892:Milk / Q000032:analysis; D010165:Palladium; D004364:Pharmaceutical Preparations / Q000032:analysis*; D013053:Spectrophotometry
D007202:Indicators and Reagents; D007454:Iodides; D004364:Pharmaceutical Preparations; C028222:cobalt-ethylenediamine tetraacetic acid chelate; D010165:Palladium; D004492:Edetic Acid