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

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