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Table 4 Calculated ratios of the spike and sample mixtures with duplicates

From: Expanded uncertainty modeling of the uranium isotope dilution standards

Spike + sample SP1 + SA1 SP1 + SA1 SP2+ SA2 SP2 + SA2 SP3 + SA3 SP3 + SA3 SP4 + SA4 SP4+ SA4
Spike/sample portion 1:4 1:2 1:2 1:2 1:3 1:3 1:2 1:2
Mixture no. SP1-1 SP1-2 SP2-1 SP2-2 SP3-1 SP3-2 SP4-1 SP4-2
235 U spike 6.6608E-05 9.34141E-05 1.31114E-05 1.31414E-05 8.05092E-06 8.059E-06 1.93253E-06 1.93642E-06
235 U sample 0.0397475 0.0262613 0.0198501 0.0198647 0.0297869 0.0298043 0.0198615 0.0198527
238 U spike 0.00918 0.01288 0.00181 0.00181 0.00111 0.00111 0.00027 0.00027
238 U sample 0.00227 0.00150 0.00113 0.00114 0.00170 0.00170 0.00114 0.00113
235 U mix sum 0.03981 0.02635 0.01986 0.01988 0.02979 0.02981 0.01986 0.01985
238 U mix sum 0.01145 0.01438 0.00294 0.00295 0.00281 0.00281 0.00140 0.00140
R(235U/238U)mix 3.47622 1.83302 6.75211 6.74569 10.59544 10.59368 14.17368 14.16706
  1. All mixtures simulated with duplicates. Ratio of U235/U238 mixture is not corrected for the mass fractionation. It will be taken into account for the extended uncertainty estimations
  2. 235U(spike/sample) = Spike/Sample Conc (g/g) × Spike/Sample (g) × 235U Frac. sample/spike
  3. 238U(spike/sample) = Spike/Sample Conc (g/g) × Spike/Sample (g) × 238U Frac. sample/spike
  4. R(235U/238U)mix = 235Uspike+sample(mix sum)/238Uspike+sample(mix sum)
  5. See Certified Reference Material (CRM) certificates issued by NBL for regarded atomic fractions. All concentration values are listed in Tables 2 and 3 for the diluted spike solutions (SP1, SP2, SP3, SP4) and sample (CRM 149). For the abbreviations, see Table 1