Organic Matter Research Lab
Providing services and support for regional and national projects
Providing services and support for regional and national projects
Organic Matter Research Lab
A hydrologic technician seen sampling water in the Sacramento-San Joaquin Delta
A hydrologic technician seen sampling water in the Sacramento-San Joaquin Delta
EEMs Plots
Excitation-emission matrices of rice, peat soil, and algae
Excitation-emission matrices of rice, peat soil, and algae
Organic Matter Research Laboratory
Welcome to the USGS CAWSC Organic Matter Research Laboratory (OMRL). The OMRL provides laboratory services and support to regional and national projects in the analysis of organic matter using the latest methods in absorbance and fluorescence spectroscopy along with standard measurement of total dissolved organic carbon and nitrogen concentration. Please contact us if you have any questions.
What is organic matter?
What is organic matter?
Close-up of a wetland, showing multiple sources of dissolved organic matter (DOM)
Publications
Procedures for using the Horiba Scientific Aqualog® fluorometer to measure absorbance and fluorescence from dissolved organic matter
Advances in spectroscopic techniques have led to an increase in the use of optical measurements (absorbance and fluorescence) to assess dissolved organic matter composition and infer sources and processing. Although optical measurements are easy to make, they can be affected by many variables rendering them less comparable, including by inconsistencies in sample collection (for example, filter por
Wetlands receiving water treated with coagulants improve water quality by removing dissolved organic carbon and disinfection byproduct precursors
Constructed wetlands are used worldwide to improve water quality while also providing critical wetland habitat. However, wetlands have the potential to negatively impact drinking water quality by exporting dissolved organic carbon (DOC) that upon disinfection can form disinfection byproducts (DBPs) like trihalomethanes (THMs) and haloacetic acids (HAAs). We used a replicated field-scale study loca
Optical properties of dissolved organic matter (DOM): Effects of biological and photolytic degradation
Advances in spectroscopic techniques have led to an increase in the use of optical properties (absorbance and fluorescence) to assess dissolved organic matter (DOM) composition and infer sources and processing. However, little information is available to assess the impact of biological and photolytic processing on the optical properties of original DOM source materials. We measured changes in comm
Science
EEMs from Different Source Material
Four excitation-emission matrices showing fluorescence from different sources of dissolved organic matter common to the Sacramento-San Joaquin Delta (California, USA): A, peat soil (euic, thermic Typic Medisaprists); B, Rice ( Oryza sativa ); C, Cattail ( Typha spp. ); and D, Algae ( Thalassiosira weissflogii ). Note, the presence or absence of fluorescence peaks, intensity of fluorescence...
Table of Analysis Methods
The OMRL provides a variety of laboratory services and support to regional and national projects in the analysis of organic matter using the latest methods in absorbance and fluorescence spectroscopy along with standard measurement of total dissolved organic carbon and nitrogen concentration (DOC and TDN, respectively).
Laboratory DQOs
The OMRL monitors laboratory performance though the use of QC data. Our laboratory QC data is reviewed daily and compiled in a manner that allows reviewers to compare the QC results to the Data Quality Objectives (DQOs) listed here.