OCCURRENCE OF MUSK XYLENE AND MUSK KETONE METABOLITES IN THE AQUATIC ENVIRONMENT

Quantification of musk xylene (MX) and musk ketone (MK) was for the fi rst time achieved in aquatic environmental samples simultaneously with their transformation products 4-amino-MX, 2-amino-MX, and 2-amino-MK at a ng/L level using liquid-liquid extraction and subsequent GC-MS an d GC with AFID detection. Thus, the transformation of nitro musks to t he corresponding amines could be studied in samples of the sewage plan t Hamburg and of the river Elbe. In the influent of the sewage treatme nt plant concentrations of 150 and 550 ng/L were found for MX and MK, respectively, while in the effluent the corresponding values were 10 a nd 6 ng/L. The amino derivatives as transformation products were not d etectable in the influent samples, however, values of 10 ng/L (2-amino -MX), 34 ng/L, (4-amino-MX), and 250 ng/L (2-amino-MK) were found in t he effluent samples. These latter concentrations were 4 to 40 times hi gher than the parent compounds. The simultaneous decrease in the nitro musk concentrations and the increase in the amino derivatives suggest that, besides adsorption at the sludge, this transformation pathway p lays an important role. In the Elbe river the concentrations of 4-amin o-MX attained at least 3 to 10 fold higher values (1 - 9 ng/L) than th e parent compound, while 2-amino-MK exhibited a concentration of 7 ng/ L. These results suggest that monitoring programmes as well as risk as sessments of nitro musks in aquatic ecosystems should include the tran s-formation products such as the amino derivatives investigated herein . (C) 1998 Elsevier Science Ltd. All rights reserved.