Critical considerations on the analysis and bioaccumulation of musk xylene and other synthetic nitro musks in fish

Several analytical methods for the residue analysis of musk xylene (MX), musk ketone (MK), and other nitro musks in fish are presented and discussed. In particular because of a publication about a fast and simple analysis without any clean-up procedure, the necessity of a thorough clean-up of fatcontaining samples is emphasized. In addition, the present knowledge about the high bioconcentration of these lipophilic pollutants in fish is summarized. In a long-term bioconcentration study we found in rainbow trouts bioconcentration factors (BCF) on a wet weight basis (BCFw) of MX from 4,200 to 5,100 while the BCF values on a lipid basis (BCFL) ranged from 115,000 to 122,000. These BCF values of MX are in good agreement with the BCF values calculated from the noctanol/water partition coefficient (log KOW = 4.90) using the Quantitative Structure-Activity Relationship (QSAR). A published study with extremely low bioconcentration factors of MX is critically discussed.