Fig. 1
Fig. 2
The ten Fraction Modern (F14C) values obtained under repeatability condition_
| Number of repetition | Value of F14C |
|---|---|
| 1 | 0.224 ± 0.006 |
| 2 | 0.241 ± 0.007 |
| 3 | 0.237 ± 0.006 |
| 4 | 0.225 ± 0.006 |
| 5 | 0.242 ± 0.007 |
| 6 | 0.230 ± 0.006 |
| 7 | 0.236 ± 0.006 |
| 8 | 0.240 ± 0.007 |
| 9 | 0.230 ± 0.006 |
| 10 | 0.231 ± 0.006 |
Counting region optimization data for glass vial_
| Counting region | Background of blank sample (cpm) | Standard (cpm) | Efficiency (%) | FOM (E2/B) |
|---|---|---|---|---|
| 20–85 | 0.42 ± 0.04 | 1072 ± 2 | 60 | 8571 |
| 15–105 | 0.63 ± 0.04 | 1276 ± 2 | 70 | 7778 |
| 10–95 | 0.93 ± 0.05 | 1407 ± 3 | 77 | 6375 |
The four Fraction Modern (F14C) values obtained under reproducibility condition_
| Number of repetition | Value of F14C |
|---|---|
| 1 | 0.244 ± 0.008 |
| 2 | 0.235 ± 0.006 |
| 3 | 0.227 ± 0.006 |
| 4 | 0.242 ± 0.007 |
Validation parameters for the determination of Fraction Modern (F14C) by conventional method when counting 4g benzene for 300 minutes_
| Validation parameters | Value | |
|---|---|---|
| Method Bias | 1.51% | |
| Repeatability | Mean Reference value = pMCreference/100 = 0.2305 ± 0.0002 | 0.23 Reference value = pMCreference/100 = 0.2305 ± 0.0002 |
| σr | 0.01 | |
| rL | 0.02 | |
| CV | 2.70% | |
| Reproducibility | Mean | 0.24 |
| σr | 0.01 | |
| RL | 0.02 | |
| CV | 3.30% | |
| Limit of detection | Ld (counts) | 2.98 |
| Minimum Detectable Activity | MDA (dpm) | 0.003 |
| Combined uncertainty | U(pMC) | 0.58 |
Reference values, Lab values and z-score values_
| Sample Code | Sample type | Reference value (F14C) Reference value = pMC reference/100 | σtarget | Lab Value (F14C) | σLab | z-score | tSIE tSIE =Transformed Spectral Index of the External Standard, the quench parameter |
|---|---|---|---|---|---|---|---|
| D | Barley | 0.1030 | 0.0100 | 0.1038 | 0.0210 | 0.04 | 682 |
| U | Humic acid | 0.2308 | 0.0002 | 0.2298 | 0.0083 | –0.12 | 683 |
| R | Murex shell | 0.7334 | 0.0004 | 0.7210 | 0.0176 | –0.70 | 685 |
| IAEA-C2 | Travertine | 0.4114 | 0.0003 | 0.4217 | 0.0114 | 0.90 | 682 |
| IAEA-C7 | Oxalic acid | 0.4935 | 0.0012 | 0.4810 | 0.0130 | –0.96 | 680 |