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Author
Edo Muñoz, Sílvia
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Abstract
Pharmaceuticals are micro-organic and pseudo-persistent pollutants with low volatility. The chemical structure of their active pharmaceutical ingredients (APIs) can be changed by biotransformation, biodegradation, and non-biotic transformation that produce metabolites or transformation products. After consumption, its metabolization in the bodies may not be completed, entering the aquatic environment as parent compounds or metabolites. In addition, some of them are not efficiently removed in WWTPs and are continuously released into the aquatic environment.
Although drugs are not considered pollutants, their research has resulted in major lines of research within the scientific world regarding environmental pollution. Although the metabolites and/or transformation products are a new field of research. For this reason, the aim of this study is to develop an analytical method for the analysis of pharmaceuticals, metabolites, and transformation products in the exits of the WWTPs, specifically in the submarine outfalls.
A new chromatographic method has been designed to separate 88 compounds (pharmaceuticals, metabolites, and transformation products) with a CORTECS T3 column (100 mm x 2.1 mm, particle size 1.6 μm) using as mobile phases 0.1% of formic acid with Milli-Q® water and 0.1% formic acid with ACN. First, the solvent of the compounds had to be selected, with the highest affinity for the stationary phase and the mobile phase, in order to obtain well-defined peaks. Following, several tests with different gradients were performed to have a good chromatographic separation between the compounds.
Once the instrumental method was developed, an extraction method has to be designed. The extraction is carried out using the SPE technique with Oasis HLB cartridges., at pH 2 and pH 7 as compounds have different physicochemical properties. Firstly, the method was tested using Milli-Q® water as a sample in order to observe the behavior of the analytes without interference due to the matrix. Secondly, wastewater from the Besós WWTP was analyzed to confirm the efficiency of the extraction method.
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