Direct noninvasive H NMR analysis of stream water DOM: Insights into the effects of lyophilization compared with whole water.

NMR spectroscopy is widely used in the field of aquatic biogeochemistry to examine the chemical structure of dissolved organic matter (DOM). Most aquatic DOM analyzed by proton NMR ( H NMR) is concentrated mainly by freeze-drying prior to analysis to combat low concentrations, frequently <100 μM C, and eliminate interference from water. This study examines stream water with low dissolved organic carbon content by H NMR with a direct noninvasive analysis of whole water using a water-suppression technique.