Combined fluorescent measurements, parallel factor analysis and GC-mass spectrometry.

Combined fluorescent measurements, parallel factor analysis and GC-mass spectrometry in evaluating the photodegradation of PAHS in freshwater systems

ABSTRACT

To better understand the transformation and photochemical fate of PAHs in aquatic environments, a custom-designed closed-circuit recirculation photodegradation system, combined with inline semi- continuous fluorescence and absorbance measurements, as well as modelling of excitation-emission (EEM) measurements with parallel factor analysis (PARAFAC), and GC-MS analysis, were combined to create a robust tool for holistically assessing the photodegradation of individual PAHs, their mixtures and photoproduct formation. Selected compounds included in the US EPA priority list, representing 2- to 6- ring compounds, were monitored individually and in mixtures, during 24 h photodegradation experiments. Experiments were conducted in solutions simulating ideal (ultrapure water) and environmentally relevant conditions (1.00 mg/L Suwannee River Natural Organic Matter (SRNOM)). The fluorescence, primary PARAFAC components and quantification data obtained by GC-MS, indicated that the decline in parent molecule concentration occurred…