Time-resolved Fluorescence Measurements of Aquatic Natural Organic Matter (NOM)

The fluorescence decay of aquatic natural organic matter (NOM) samples was investigated using the time-correlated single photon counting technique (TCSPC). Two different approaches for the data analysis are presented: the discrete component approach (DCA) and the exponential series method (ESM). The parameter set obtained in the DCA is discussed in terms of characterization for NOM of different origins. However, the obtained parameter set can only be interpreted as operationally defined. Using the ESM for a fluorescence decay time distribution analysis no a priori assumption about the number of fluorescing components was introduced into the data analysis. The interpretation of fluorescence decay time data for samples before and after ozonation is in good agreement with results of other analytical methods.