Using complementary analyses for a more complete characterization of dissolved SOM

Objective:

To standardize different analytical techniques for chemical characterization of Water Soluble Organic Carbon (WSOC) for soils sampled across a coastal gradient.

Employ techniques that may have different analytical windows, or techniques that may target different molecules/functional groups to provide a more comprehensive understanding of WSOC. For each technique, try to get as complete a picture of the SOM characterization, so we can see how the techniques compare/provide complementary information.

Soils were collected from:

1. Old Woman Creek
2. GCReW

From each site, soils were collected from the upland forest (O/A and B horizons), transitional forest (O/A and B horizons) and wetland (surface only). Thus, we had 5 soils from each site = 10 soils total.

Each soil was shaken with water to get water extractable organic carbon, with 5 replicates. These extracts were analyzed using different analytical techniques.

Analyses

1. FTICR-MS
   • positive mode ESI
   • negative mode ESI
2. Fluorescence/PARAFAC
3. NMR
   • D2O as solvent
   • SPE, then used D2O as solvent