Analysis of polystyrene in polluted sediments by pyrolysis gas chromatography mass spectrometry

The use of pyrolysis combined with gas chromatography and mass spectrometry for the analysis of polystyrene in sediments is described. The method is applied to a sediment core of the Lagoon of Ravenna (Pialassa Baiona); in these sediments, polystyrene is detected at mg/g levels in surface layers. Dried sediment samples are directly pyrolyzed in a quartz tube holder, the peak area of the evolved styrene is determined in the single ion monitoring mode, and polystyrene concentration is calculated from the appropriate calibration curve. Linear plots of styrene peak area versus polystyrene content are obtained by pyrolyzing the polymer in the presence of various matrices: calcite, quartz, kaolinite, montmorillonite, and whole sediment. The pyrolytic behavior of polystyrene is strongly affected by the presence of clay minerals, whereas calcite and quartz exhibit a lower influence. The effect of other organic constituents, such as humic substances and styrene-butadiene rubbers, is discussed.