Enantioselective analysis of polycyclic musks as a versatile tool for the understanding of environmental processes

Abstract

In this chapter the application of enantioselective chromatography to process studies related to the microbial, enzymatic and photochemical transformation of chiral polycyclic musks will be summarised. A detailed discussion on enantiomeric ratios (ER) of HHCB, AHTN, ATII and AHDI as well as of the main HHCB metabolite HHCB-lactone analysed in tissue extracts of 18 fish samples (rudd, tench, crucian carp, eel) and one pooled zebra mussel sample from the pond of a municipal sewage treatment plant in the Federal State of Schleswig-Holstein (Germany) will be given. In addition, three water samples taken at the effluent of the sewage plant, as well as two water samples, and two series of semipermeable membrane devices (SPMDs) consisting of six samples each from the pond were included in the study. This comprehensive data set allowed a reliable evaluation of species dependent metabolisation processes. The pattern of the polycyclic musks in the chromatograms obtained by enantioselective gas chromatography seemed to be typical of each species like a fingerprint. Very strong enantioselective metabolisation can be concluded for trans- and cis-HHCB and the respective HHCB-lactone (with a preferential metabolisation of the 4S enantiomers) as well as for trans-ATII in crucian carp. With ER values ≤0.1 for trans-HHCB and trans-ATII the highest enantioselectivity was observed within this class of xenobiotics. The values for the pooled mussel and SPMD samples reflect the water values. The exact assignment to the respective enantiomers was in part possible by pure enantiomeric standards.