Trace enrichment, chromatographic separation and biodegradation of cytostatic compounds in surface water

A trace analytical procedure for the cytostatic drugs carmustine, chlorambucil, cisplatin, cyclophosphamide, cytarabine, etoposide, 5-fluorouracil, melphalan, methotrexate, and vinblastine was developed in order to evaluate the environmental hazards of these drugs in clinical waste water and sewage treatment plants. The analysis was performed using solid phase extraction with subsequent HPLC separation and quantitative determination by gradient elution techniques with DAD and fluorescence detection. Detection limits after the clean-up and enrichment procedure vary from 0.002 to 0.2 mg/L. A simulation of the degradation processes under conditions as close as possible to those in a real sewage plant showed that cisplatin and cyclophosphamide are not biodegradable, but cytarabine and 5-fluorouracil are biodegradable in different magnitudes. The biodegradation process of methotrexate is combined with the generation of the toxic and persistent degradation product 7-hydroxymethotrexate.