Absolute isotopic abundance ratios of three common lead reference samples

摘要: Abstract The absolute isotopic abundance ratios have been determined for three common lead reference samples, using solid-sample mass spectrometry. Samples of known composition, prepared from nearly pure separated 206Pb and 208Pb isotopes, were used to calibrate the spectrometers. resulting values are as follows: GS 4: 204Pb/206Pb = 0.061888 ± 0.000065, 207Pb/206Pb 0.95342 0.00036, 208Pb/206Pb 2.2181 0.0010; NBS 200: 0.068353 0.000072, 1.00538 0.00038, 2.3675 0.0011; C.I.T. Pb Std.: 0.060151 0.000063, 0.93081 0.00035, 2.1835 0.0010. indicated uncertainties overall limits error based on 95% confidence mean allowances effects sources possible systematic error.