Characterisation of organic pollutants in textile wastewaters and landfill leachate by using toxicity-based fractionation methods followed by liquid and gas chromatography coupled to mass spectrometric detection

In the present work, the characterisation of toxic organic compounds present in complex mixtures like textile effluents and landfill leachates is proposed. The protocol developed for the wastewater characterisation is based on solid phase extraction (SPE) combined with toxicity-fractionation followed by high temperature-gas chromatography-mass spectrometry (HT-GC-MS) and liquid chromatography-mass spectrometry (LC-MS). In this work Daphnia magna was used as the target organism to identify the toxic compounds in the different fractions. The highest toxicity was observed in the fractions exhibiting log Kow (octanol¯water partition coefficient) between 1.7 and 5.16. After SPE followed by GC-MS and LC-MS using atmospheric pressure chemical ionisation (APCI) the compounds identified in the more toxic fractions were bis(2-ethylhexyl)phthalate, dibutyl phthalate, alcohol decyclic alcohol polyethoxylated, disulphonate hydoxynaphthalene, nonylphenol polyethoxylated and nonylphenol isomers. In addition to the toxicity based fractionation, a sequential solid phase extraction protocol (SSPE) followed by LC-APCI-MS, LC-electrospray (ESI)MS and ion-pair chromatography (IPC)-ESI-MS) was also applied to the raw samples in order to identify the major number of polar organic pollutants.