Determination of 5-fluorouracil in hospital effluents

Cytostatic anticancer drugs are an increasingly important issue in the environmental debate, mainly due to the lack of knowledge about the fate of these toxic substances. Over the last decades, 5-fluorouracil (5-FU) has been one of the most frequently used antineoplastic agents and may, therefore, be regarded as one of the pilot substances for environmental contamination. As a prerequisite for these investigations, a method for the determination of 5-FU in hospital effluents has been developed. Waste water samples were enriched by solid-phase extraction on ENV(+) columns (concentration factor 500) and analysed by capillary electrophoresis using a buffer containing 80% 160 mM sodium borate buffer (pH 9.5) and 20% acetonitrile (v/v). This method is applicable within the range 5-500 microg 5-FU L(-1). The standard curve (correlation coefficient >0.99) was linear with recovery rates from 80 to 96% and an accuracy from 9.0 to 20% (intra-assay standard deviation 0.7-8.9%; inter-assay standard deviation 2.2-9.5%). Based on the consumption of 5-FU in oncologic departments and the detection limit of 1.7 microg L(-1), this method covers the range necessary to evaluate 5-FU in hospital effluents. The applicability of the method was proven by chemical analysis of real hospital waste water samples. Obtained over a time period of 1 month (range 20-122 microg 5-FU L(-1)), the results were similar to those calculated by an input-output model. The presented method provides an analytical tool necessary to face the monitoring of environmental contamination problems.