Structure elucidation of the three most important toxaphene congeners by X-ray analysis

Three of the most frequently detected toxaphene components in environmental samples are the chlorobornanes 2-exo,3-endo,5-exo,6-endo,8b,8c,10a,10b-octachlorobornane (Parlar No. 26); 2-exo,3-endo,5-exo,6-endo,8b,8c,9c,10a,10b-nonachlorobornane (Parlar No. 50), and 2,2,5,5,8b,8c,9c,10a,10b-nonachlorobornane (Parlar No. 62), whose structures could not be completely elucidated by spectroscopical methods. This paper now describes the X-ray structure analysis of the three compounds and presents their exact crystal structure.     

Determination of VOCs in yellow eel from various inland water bodies in Flanders (Belgium)

Twenty freshwater eels caught in Flanders (Belgium) were analysed by GC-MS for a total of 52 VOCs. The most prominent VOCs are the BTEX and a number of chlorinated compounds such as chloroform and tetrachloroethene. The observed concentrations which, typically, were in the low ng/g wet weight range, could be linked to the major emission sources and the present study gives new evidence that combustion of fossil fuels is a major source of BTEX in the environment. The concentration levels in eels seem to be a reflection of the actual concentrations in their environment. For eels from the same location similar patterns and concentrations were observed, and the concentrations agree with what can be expected from those of the water column. Generally speaking, the observed concentrations do not seem to pose a threat for organisms. More definite statements will, however, require a larger dataset. The study suggests that the yellow eel can possibly be used as a biomonitor or sentinel organism for VOCs.     

Raumbezug in der Umweltbeobachtung des Bundes und der L?nder

Ohne Zusammenfassung Ein ausführliches Vorwort finden Sie under DOI: http://.dx.doi.org/1065.65/uwsf2000.05.019