Corrections for contamination background in AMS C-14 measurements

Measurements of C-14/C-13 ratios were made on samples of Oxalic Acid and C-14 ''dead'' materials spanning the mass range from 10 mu g to similar to 1 mg. These measurements have allowed the determination of both the amount, and the C-14 content, of the contaminant carbon introduced during sample processing in our laboratory. These data were used to correct measured C-14/C-13 ratios obtained from ANU Sucrose and ''similar to one-half-life old'' test samples for the influence of the contaminant, The test samples spanned the 10 mu g to similar to 1 mg mass range and the corrections were made using three different formulae, The results obtained from these calculations allow the accuracy of these background correction formulae to be evaluated.