Add time:07/13/2019 Source:sciencedirect.com
The dynamics of organohalogen contaminants and their metabolites are best studied over time by analysis of biota at high trophic levels. In this study, time trends, 1971–2001, of bis(4-chlorophenyl) sulfone (BCPS) and of methylsulfonyl-substituted metabolites of PCBs and 4,4′-DDE, were investigated in eggs of guillemot (Uria aalge) hatching in the Baltic Proper. Temporal trends of PCBs, trans-nonachlor, β-HCH, 4,4′-DDT, and 4,4′-DDE were also assessed. Tris(4-chlorophenyl) methane (TCPMe), a 4,4′-DDT by-product, was detected in the eggs. The concentration of BCPS ranged between 2.6–0.76 μg/g on a lipid weight basis over the three decades and showed a significant 1.6% annual decrease. Three metabolites of PCBs, i.e. 3′-MeSO2-CB101, 4′-MeSO2-CB101 and 4-MeSO2-CB149, were quantified in all samples over time and showed an annual decrease of approximately 3% compared to MeSO2-DDE with a decrease of 8.9%. The methylsulfonyl-PCB and -DDE metabolites are eliminated more slowly than the persistent PCB congeners and 4,4′-DDE. Trans-nonachlor decreases by 16% compared to 19% and 9% for 4,4′-DDT and β-HCH, respectively. The concentration of TCPMe in guillemot decreased by 8.2% per year. A linear relationship was found between TCPMe and 4,4′-DDE concentrations which supports the theory that TCPMe has an origin as a contaminant in commercial 4,4′-DDT products. The very slow decrease in BCPS concentrations is notable and remains to be explained. BCPS is still present at rather high concentrations in the guillemot eggs. The enantiomeric fraction varied between 0.27 and 0.67 which indicates less of a specific retention of the chiral MeSO2-PCBs in guillemot eggs than in grey seal tissues, for example. Independent of meta- or para-substitution of the sulfone group, the most accumulative atropisomer of each of four MeSO2-PCB pairs has been assigned an absolute R structure.
We also recommend Trading Suppliers and Manufacturers of 4-CHLOROPHENYL 1-[1-(METHYLSULFONYL)-1H-PYRAZOL-5-YL]ETHYL ETHER (cas 321998-04-3). Pls Click Website Link as below: cas 321998-04-3 suppliers
About|Contact|Cas|Product Name|Molecular|Country|Encyclopedia
Message|New Cas|MSDS|Service|Advertisement|CAS DataBase|Article Data|Manufacturers | Chemical Catalog
©2008 LookChem.com,License: ICP
NO.:Zhejiang16009103
complaints:service@lookchem.com Desktop View