Characterizing dissolved organic matter fluorescence with parallel factor analysis.


Colin A. Stedmon & Rasmus Bro

*Corresponding author e-mail:

The combination of EEM fluorescence and parallel factor analysis has proved to be a promising tool for studying DOM. These relatively inexpensive fluorescence measurements can be used in combination with other measurements to rapidly quantify and characterize DOM across a range of environments. This approach also has great potential in a wide range of other applications such as drinking water monitoring, waste water treatment control and the evaluation of ballast water exchange in ships. However, as with many new techniques, it is not as straightforward as could be desired and there are a range of potential pitfalls. For the approach to persist and become a trustworthy method, a basis for a standardized approach was required.

This paper and the tutorial in the appendix provides a suitable starting point for developing this approach further.

In addition, the associated Matlab toolbox provides the algorithms needed to analyze EEM data according to the tutorial

Version history:
V1-0 06/may/2008
-Original version.
V1-1 23June 2008.
-Small errors in help text corrected.
-Corrected RandInitAnalysis, plotted number of iterations instead of sum of squared error.
-New function called MeanError added.
v1-3.9 October 2008.
-Edited the EEMCut fucntion to provide three plotting options (Yes-pause, no-pause and no plot).
-EEMCut modified to remove need for flucut.
-Edited all of the plot fucntions so that an error message does not occur after plotting the last sample.
v1-4 16 October 2008.
-Edited the toolbox so that PARAFAC is embedded in the fucntions that call it. This means that there should not be any conflicts with the PLS_toolbox (if installed)
-DOMFluor.m added.
v1-5 27 October 2008
-Edited EEMCut to correct an earlier error. Before it did not plot the uncut EEm but twice the cut eem.
v1-6 07November 2008.
-Edited EEMCut, PlotEEMby4, PlotEEMby4fixedZ, PlotSurfby4, PlotSurfby4fixedZ, for a minor error that reuslted in not plotting last sample.
v1-7 27February 2009.
-Edited Compare2Model, COmpare2ModelSurf, EvalModel and EvalModelSurf for an error that reuslted in not plotting last sample in a data set.