Detergent metabolites

The first national-scale study of emerging contaminants in the United States found that such compounds were commonly present in stream systems, with 80% of the streams sampled having at least one compound detected [11]. Over 60% of the chemical concentrations exceeding 1 xg/L were from three detergent metabolites (4-nonylphenol, 4-nonylphenol monoethoxylate, and 4-nonylphenol diethoxylate). In addition, transformation products also were frequently detected (e.g., cotinine, 1,7-dimethylxanthine, erythromycin H2O). This study indicated the enormous potential for parent compoimds to degrade during environmental transport and for the transformation products to contribute much of the relative loading of these contaminants. The results confirm the need to include both parent compoimds and transformation products in occurrence studies. 

Alkylphenol ethoxylates (APEO) are no longer used in household detergents in the Western world and represent only a minor portion of the whole non-ionic surfactants group. Even if APEO is a group of surfactants of no commercial importance anymore, there is a need for risk assessment since these compounds are still present in the aquatic environment due to the recalcitrant nature of some of their metabolites (see Chapters 6.1, 6.2.1, 6.3.1 and 6.4). More attention should be given in the future to other non-ionic surfactants like alcohol ethoxylates. 

Viala et al. published a method for GC detection of chloroquine and monodes-methylchloroquine in hair of patients who had been treated with chloroquine for several months. The samples were washed with detergent (DET) and then dissolved in hot potassium hydroxide. After the extraction with ether, a thin-layer procedure was used for cleaning up. The quantitation was made by GC with a NP-FID. Chloroquine and its metabolite were identified by GC/MS. The GC detection of chloroquine and with NP-FID detector was reported by Ochsendorf et al. They quantitated the drug in different hair sections and found a correlation to the pharmacological behavior of the substance. Couper et al. described a GC screening with NP-FID for antidepressants and antipsychotic drugs in hair from post-mortem cases. 

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