ESTIMATING DISSOLVED ORGANIC-CARBON IN NATURAL-WATERS BY UV ABSORBENCY (254 NM)

A close correlation exists between dissolved organic carbon (DOG) conc entration and UV absorbance at 254 nm (A(254)) in natural waters. DOC and A(254) were measured for soil solutions, throughfall, stemflow, an d surface waters collected from a forested sire located in eastern Aus tria. The slopes of Lines determined by linear regression of DOC versu s UV absorbance were very similar to those determined for wet depositi on and throughfall samples collected in Nordrhein-Westfalen, Germany b y Bartels (1988). The intercept of the regression line in the current study indicates that approximately 1 mg L(-1) of non-UV-absorbing DOC is present; it is suggested that this is due to saturated aliphatic co mpounds such as acetate or formate.