Dissolved organic matter (DOM) is a complex mixture of organic compounds found in all
natural waters. Its composition affects its reactivity towards numerous processes. Its
composition is a function of both its source (e.g., allochthonous or autochthonous) as well
as the extent of environmental processing it has undergone (e.g., chemical or biological
degradation). Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR MS) allows
for the characterization of dissolved organic matter at the molecular level. The water
sample was collected near the NTL-LTER research buoy on Lake Mendota. Formula assignments
were made to raw mass to charge ratios detected in the mass spectrum using a custom
processing script and resulting in a list of chemical formulas making up the DOM
sample.<br/>