title: Estimation of dissolved organic carbon (DOC) concentrations in nanoliter samples using UV spectroscopy.
abstract: A simple analytical system has been developed and tested for estimating dissolved organic carbon (DOC) concentrations in nanoliter samples of sediment porewaters. The system consists of a loop injector that introduces 200 nL of sample directly into the capillary tubing connected to a scanning UV-VIS detector equipped with a 35-nanoliter capillary flowcell. Analysis of DOC by spectroscopic and high-temperature catalytic oxidation (HTCO) methods on the same samples showed a strong linear correlation between UV absorbance at 254 nm and HTCO-DOC concentration, allowing the DOC quantification. The simplicity and the robustness of the UV system allow DOC measurements in the field at a rate of 30 samples/h. We have used the UV system successfully for determining high-resolution distributions of porewater DOC concentrations in sediments at millimeter scales.
authors.affiliation: Institut des Sciences de la Mer de Rimouski, Université du Québec à Rimouski, Canada.
authors.forename: B
authors.initials: B
authors.lastname: Deflandre
authors.forename: J P
authors.initials: JP
authors.lastname: Gagné
mesh_terms: D002244:Carbon / Q000032:analysis*; D009930:Organic Chemicals / Q000032:analysis*; D015203:Reproducibility of Results; D018401:Sample Size; D012680:Sensitivity and Specificity; D012996:Solutions; D013056:Spectrophotometry, Ultraviolet / Q000295:instrumentation* / Q000379:methods*; D014867:Water / Q000737:chemistry*
chemical_list: D009930:Organic Chemicals; D012996:Solutions; D014867:Water; D002244:Carbon