Study On Specification And Application Of Organotin Compounds In Industrial Products And Ecological Environment

Organotin compounds (OTCs) are organometallic compounds of tin and carbondirectly bonded, mainly used as plastic heat stabilizer, wood preservatives,agricultural pesticides, antifouling paints and textiles fungicide. With highly effectiveanti-heat stabilization and anti-corrosion properties, OTCs have become one of themost widely used organometallic compounds. Therefore, OTCs are studiedcontinuously on the further use and development, although they have been listed asthe Environmental Endocrine Disrupting Chemicals.OTCs are released into human life through the use of plastic products, woodproducts and other daily consumer goods and production process, and into theecological environment finally. They show considerable toxicity toward livingorganisms, high environmental persistence and the ability to transfer along the trophicchains.Based on the regulations of use limitation, the determination of OTCsspecification in plastic and wood products is studied, and their pollution levels aremonitored in inland freshwater and offshore marine sediments. Main research resultsare shown as follows:（1） The orgaotin heat stabilizers include methyltin, butyltin and octyltin, andthey usually are used simultaneously with alkyltin and bisalkyltin for the bestthermal stability. The simultaneous determination of9organotin compounds isstudied with GC-MS, including methyltin for the first time. The self-preparedpositive samples of polyvinyl chloride (PVC), acrylonitrile butadiene styrene plastic (ABS), polystyrene (PS) and polycarbonate (PC) at3concentration levelsare made for the method validation. The results show that the method has goodaccuracy and precision with the recovery rate of85.9%to107.2%and the relativestandard deviation less than9.97%. There is no significant difference between theresults from GC-MS and ICP-OES.（2） Bis(tributyltin)oxide is the most widely used wood preservatives with thebest preservative effect and no color contamination. According to the preservativeretention capacity, effective concentration and timber density, the self-preparedsamples at2levels are made of pine wood and plywood for experimentalcondition optimization. The GC-MS method with ethanol ultrasonic extractionwas developed for the determination of4organotin compounds in timber andwood products for the first time. The results prove a good reproducibility andrecovery with a linear range of0.1~20mg/L. The average recoveries are in therange of83.6%~103.2%with the relative standard deviations less than9.75%.（3） The pollution in ecological environment comes mainly from the OTCsproduction and use in industry and agriculture, and the OTCsenter fresh waterthrough volatilization, dissolution and leaching. From2009-2010, the pollution oforganotin, butyltin, octyltin and phenyltins, is investigated in inland freshwater(58stations) throughout China for the first time. The investgated results show that,the organotin pollution level of fresh water in China, as the major producing andusing country of organotin additives, has exceeded the foreign pollution levelpartly, but no significant increasing trend is observed.（4） Marine sediments is not only an important sink of OTCs in the ecologicalenvironment, but also a significant source for persistent OTCs via re-releasingprocess. From2009-2010, pollution of organotin including butyltin, octyltin andphenyltins, is investigated in offshore sediments from56stations in the Bohai Sea,the Yellow Sea and the Yangtze River Estuary. The high concentrations of OTCsare found mainly in the port and shipping terminals, indicating that antifoulingpaint is still the major release source of the organotin pollution. Compared withthe existing monitoring data from home and abroad, domestic pollution levels in marine sediments are significantly lower than those in other countries, and keepbasically stable.