I$sup 131$-POLYVINYLPYRROLIDONE

The preparation and iodination of an I/sup 131/-labeled polyvinylpyrrolidone suitable for diagnostic uses is described. After purification and fractionation a highly stable product with less than 1% of free I was prepared. Molecular weights were kept within desired limits and 50% of the I/sup 131/ used for labeling was incorporated in the product. The purity of the iodinated PVP was checked by piper chromatography, and molecular weights were determined by viscometry and osmometry. Some factors influencing the stability of the iodinated PVP such as purity, temperature, pH, oxygen, and radiation were investigated. A hypothesis for the structure of iodinated PVP is given. The iodinated PVP is probably a 4-iodo-polyvinyl-pyrrolidone. (auth)