| Abstract
| - A literature search was performed for dissolved organiccarbon/water partition coefficients for nonionic organicchemicals (KDOC), and KDOC data were taken from more than70 references. The KDOC data were evaluated as afunction of the 1-octanol/water partition coefficients(KOW). A predictive relationship of KDOC = 0.08KOW with95% confidence limits of a factor of 20 in either directionwas developed using KDOC data based upon naturallyoccurring dissolved organic carbon. Inclusion of KDOC datafor Aldrich humic acid, a reagent-grade organic carbon,resulted in a slightly different predictive relationship of KDOC= 0.11KOW with 95% confidence limits of a factor of 14in either direction. The large uncertainties in theserelationships are, in part, caused by the variability instructure and composition of dissolved organic carbon(DOC) in sediments, soils, and surface waters. This variabilityis not accounted for by the hydrophobicity parameter.For individual chemicals, ranges in KDOC values approaching2 orders of magnitude were observed among investigationsusing Aldrich humic acid as the DOC. These largeranges of KDOC values suggest that measurement techniquesare also, in part, responsible for the large uncertaintiesin these relationships.
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