Screening of Trace Organic Compounds in Municipal Wastewater by Gas Chromatography-Mass Spectrometry

This research proposes the simple and reliable procedure of screening a wide range of polarity trace organic pollutants in influent and effluent municipal wastewater. Such a method includes concentrations of analytes on C18 bonded phase cartridges and its subsequent eluting with organic solvents of different polarity: n-hexane, ethyl ether, and methanol. Each eluate is directed to gas chromatography/mass spectrometry (GC/MS) separation and detection. Silylation of compounds eluted with ethyl ether and methanol was done prior to chromatographic analysis. For reliable identification of the unknown organic compounds a combination of three independent parameters: mass spectra, retention indices and partition coefficients in n-hexane/ acetonitrile system was employed. More than 120 compounds were identified and semi-quantitatively determined in municipal wastewater from the Wastewater Treatment Plant in Białystok, mainly from the groups of aliphatic acids, alcohols and polyalcohols, and carbohydrates. Compounds potentially harmful to the environment and found in the analyzed municipal wastewater are: 2,6-ditertbutylhydroxytoluene, phosphoric acid, phthalic acid esters, phenol, and drug remnants (ibuprofen, naproxen, and caffeine).