METHYLTIN AND BUTYLTIN COMPOUNDS IN WATER AND SEDIMENTS OF THE RHINE RIVER

The occurrence of inorganic tin and methyl- and n-butyltin compounds in water and sediments of the Rhine river was investigated. Speciation was performed by volatilization of the tin species as the corresponding hydrides, separation on a chromatographic packing material, and detection by atomic absorption spectrometry; sediments were extracted by refluxing in methanol/HCl. Analysis of Rhine water samples showed dimethyltin, monobutyltin, and dibutyltin to be present in the low ppt range. Rhine sediments contained methyl- and butyltin compounds in the mid ppb range. High concentrations of tributyltin were found in harbor locations. The contributions of the various sources to the overall input of methyl- and butyltin compounds into the Rhine are discussed. Effluents from municipal sewage plants may be a significant source of organotin compounds to the Rhine river.