2005/01/01 by Jeomshik Hwang, Ellen R M Druffel, Ellen R. M. Druffel
Environmental Science · Physics and Astronomy · Earth and Planetary Sciences · #Isotope Analysis in Ecology #Nuclear Physics and Applications #Groundwater and Isotope Geochemistry
paper · pdf · doi:10.1017/s0033822200052218
Contaminant carbon (blank carbon) was studied for its impact on the carbon isotope measurements (Δ 14 C and δ 13 C) of 3 organic compound classes of oceanic particulate organic matter. Two methods of blank correction and associated uncertainties were studied. First, the carbon blanks were quantified manometrically and the isotope ratios of the blank carbon were measured directly. Second, the isotope ratios of the blank carbon were estimated using the standard dilution method from the difference in Δ 14 C values between unprocessed and processed standards. The 2 methods agreed within the uncertainties. The standard deviations of numerous Δ 14 C measurements made on processed standard compounds were comparable to those of real samples. Blank correction using the standard dilution method is much less sensitive to the error in determination of blank carbon mass than is correction using the directly measured mass and Δ 14 C values of the blank carbon. The standard dilution method is recommended for correcting Δ 14 C analyses of small samples that involve incorporation of a significant amount of blank carbon.