The determination of iodine in materials of biological interest

Two microanalytical methods for the determination of iodine in material of biological interest were studied: neutron-activation analysis and automated colorimetry (iodide catalysis of the As(III)-Ce(IV) system). The methods were applied to the analysis of samples of water, biological fluids, common salt and solid substances such as tissues, stools and foods. The particular procedures set up and optimized for the different substances with both methods are described and discussed, and the respective advantages in terms of sensitivity, accuracy, precision and speed are compared. The sensitivity and accuracy of both techniques were found to be quite adequate. Automated colorimetry is to be preferred for its precision and operative simplicity, while activation analysis retains full validity as a reference check method.