DETERMINATION OF TIN IN ORGANOTIN STABILIZED POLY(VINYL CHLORIDE) BY GRAPHITE-FURNACE ATOMIC-ABSORPTION SPECTROMETRY

Analytical methods were developed for controlling the content of organotin stabilizers in plasticized PVC used for medical plastic products. Four methods of sample preparation were compared: extraction with nitric acid, decomposition with a mixture of sulphuric acid and hydrogen peroxide, extraction with diethyl ether and dissolution in tetrahydrofuran. The content of tin in the samples was determined by GFAAS. The most efficient methods were acidic decomposition and dissolution of the PVC samples. With these two sample preparation methods the detection limit of tin in PVC is 0.4-mu-g/g.