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

Abstract

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.

Structural characterization of aquatic humic substances ? The need for a multiple method approach

“…Fluorescence spectra show source-dependent maxima for the excitation and emission wavelength (Cabaniss and Schuman, 1987;Kumke et al, 1998a). For UV excitation, maximal fluorescence intensities lie in the emission wavelength region of about l = 450 to 500 nm.…”

Spectroscopic Characterization of Fulvic Acid Fractions of a Contaminated Groundwater

“…The time-resolved fluorescence experiments were performed with a FL900 lifetime spectrometer (Edinburgh Instruments, Edinburgh, UK) in the time-correlated single photon counting (TCSPC) mode. The TCSPC set up is described in detail elsewhere [15,16]. For the decay time measurements the emission monochromators were set to a spectral bandpass of 9 nm.…”

“…In addition a different approach using a distribution analysis with no initial guess on the number of decay times was used. The data analysis is described in detail elsewhere [15][16][17][18].…”

Dissolved Organic Matter (DOM) in Natural Environments

“…Fluorescence spectra show maxima for the excitation and emission wavelength which are source -dependent (Cabaniss and Shuman, 1987 ;Senesi et al, 1989 ;Kumke et al, 1998 ;Kumke and Frimmel, 2002 ). However, the assignment of the structures responsible for the fl uorescence behavior has still not been satisfactory.…”