Makoto Nagase

Determination of tributyltin and triphenyltin compounds in hair and fish using a hydrolysis technique and gas chromatography with flame photometric detection

A hydrolysis technique and a GC method are described for the determination of tributyltin and triphenyltin compounds in human hair and fish tissue. A sample was hydrolysed with a potassium hydroxide-ethanol-water solution. Tributyltin and triphenyltin compounds in the hydrolysate were extracted with toluene, and then impurities in the extract were eliminated with anion- and cation-exchange resins. After propylation of the organotin compounds, a yellow impurity was removed with a Sep-Pak florisil cartridge, and the two propylated organotin compounds were separated using a silicone OV-1 GC column and determined by flame photometric detection. The limits of determination of tributyltin and triphenyltin compounds in the sample were 5 and 10 ng g-1, respectively, in their chloride forms. The recoveries of tributyltin chloride from hair samples were 78.8 and 90.8%, respectively, when the spiked amounts were 20 and 200 ng. The recoveries of triphenyltin chloride from hair samples were 71.7 and 72.7%, respectively, when the spiked amounts were 40 and 400 ng. The recoveries of the organotin compounds from fish were similar to the recoveries from hair.

Hydrogen sulfide production by sulfate-reducing bacteria utilizing additives eluted from plastic resins:

In the present study it was demonstrated that organic additives eluted from plastic resins could be utilized as substrates by sulfate-reducing bacteria. Two laboratory-scale experiments, a microcosm experiment and a leaching experiment, were conducted using polyvinyl chloride (PVC) as a model plastic resin. In the former experiment, the conversion of sulfate to sulfide was evident in microcosms that received plasticized PVC as the sole carbon source, but not in those that received PVC homopolymer. Additionally, dissolved organic carbon accumulated only in microcosms that received plasticized PVC, indicating that the dissolved organic carbon originated from additives. In the leaching experiment, phenol and bisphenol A were found in the leached solutions. These results suggest that the disposal of waste plastics in inert waste landfills may result in the production of H2S.

Determination of dibutyltin compounds in soft polyurethane foam by gas chromatography with flame photometric detection

A gas-chromatographic (GC) method was developed that permits the determination of dibutyltin compounds in soft polyurethane foam. Polyurethane foam and dibutyltin compounds contained in it were dissolved in sulfuric acid, and only the polyurethane was separated out by adding distilled water. Dibutyltin compounds were converted to dibutyltin dichloride by reaction with hydrochloric acid, and dibutyltin dichloride was extracted with toluene after precipitating sulfate as barium sulfate. After propylation, the organotin compound was purified by using a Sep-Pak Plus silica cartridge and was determined by GC using a DB-1 capillary column. The detection limit for dibutyltin compounds was 8.6 ng g–1, in their chloride form. Dibutyltin compounds were detected from soft polyurethane foam at the level of 9.3–38.0 ng g–1. The recovery of dibutyltin dichloride from soft polyurethane foam was 71.5%, when the spiked amount of dibutyltin dichloride was 5 ng.