Organotin Accumulation Status of Organisms and Environments in Luermen Stream and Sih-Cao Fishing Port

• Main Authors: Chuan-Ho Tang, 唐川禾
• Other Authors: Wei-Hsien Wang
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/cz844a

博士 === 國立中山大學 === 海洋生物科技暨資源學系研究所 === 95 === The goal of this study is to establish an accurate, simple and fast method for analysis of organotin in bio-tissues and for routine analysis of organotin in pollution control. This study also conducted the field survey investigating the accumulation status of butyltin (BT) in organisms and environments for validation of analytical method and applicability in different environmental samples. Stations had been set up from the Sih-Cao fishing port to the upstream of Luermen Stream Estuary. General water quality factors were measured in situ, and water samples, suspended particles, Pacific oysters (Crassostrea gigas), green mussels (Perna viridis), and rockshells (Thais clavigera and Thais rufotincta) were collected in summer (July 2003) and winter (February 2004) seasons and the concentrations of butyltins were measured. Surface sediment samples were also collected from each sampling station and the concentrations of butyltins were measured to present pollution status of butyltins in Luermen Stream Estuary. To determine butyl- and phenyl-tins in fish muscle, a method including base digestion pretreatment, followed by an ethylation-extraction procedure together with gas chromatography-flame photometric detection (GC-FPD) analysis is outlined. Parameters that affect analyte recovery were investigated and optimized. A solution of 3 % (w/v) potassium hydroxide and 1 h digestion time at 60 ℃ were chosen in the base digestion step to ensure complete solubilization of fish muscle and the decomposition of organotins was found to be negligivle. We found that the ratio of fish muscle/reaction solution volume should not exceed 0.2 g (dry weight) per 100 mL in order to avoid the matrix effect caused by the binding of hydrolyzed fish tissue with organotin ions. Ethylation of organotins were conducted at pH 6~7 with a 1 % (w/v) sodium tetraethylborate (NaBEt4) solution for 1 h. This simple and timesaving procedure could be applied to the routine analysis of organotins in other bio-tissues. The BT content of environments and organisms reflected that the tributyltin (TBT) pollution levels were higher in Sih-Cao fishing port than in Luermen Stream. The BT content of organisms reflected more detail TBT pollution status between Sih-Cao fishing port and Luermen Stream. However, the MBT pollution status in Luermen Stream was not reflected in MBT accumulation status of organisms. The ability of TBT accumulation in oysters and mussels was higher than in rockshells. Moreover, oysters had higher TBT accumulation ability than mussels at lower TBT pollution level, but following the increase of TBT pollution level, the ability of TBT accumulation in oysters had shifted to be lower than in mussels. The results also showed that in the higher TBT pollution level, the ratios of MBT and DBT over the total butyltins had changed to higher status and the bioaccumulation factors (BAF) had changed to smaller values in oysters and rockshells. In mussels, this phenomenon was not significant. However, the organisms (oyster, mussel and rockshells) revealed smaller BAF of TBT in Luermen Stream than in the Sih-Cao fishing port entrance. For oysters and mussels, the TBT contents and the composition ratios of TBT in total butyltins were both higher in winter season. All organisms (oysters, mussels and rockshells) had higher ability to accumulate TBT according to the larger BAF observed in summer season. The ability of TBT accumulation in rockshells was lower than in oysters or mussels. Moreover, the BT accumulation status was mainly composed of MBT and DBT (the metabolites of TBT ) in rockshells and TBT in oysters and mussels. That was attributed to higher metabolic rate of TBT in rockshells.