CCQM-K156
MEASURAND L-PFOA in ground water
NOMINAL VALUE 5 ng/kg
Degrees of equivalence represented by Di = (xI - xR) and its expanded uncertainty Ui at a 95 % level of confidence, both expressed in ng/kg.
Results given in absolute values.
CCQM-K156
MEASURAND L-PFOA in ground water
NOMINAL VALUE 5 ng/kg
Degrees of equivalence represented by Di = (xI - xR) / xR and its expanded relative uncertainty Ui at a 95 % level of confidence, both expressed in %.
Results given in relative values.
CCQM-K156
MEASURAND L-PFOS in ground water
NOMINAL VALUE 4 ng/kg
Degrees of equivalence represented by Di = (xI - xR) and its expanded uncertainty Ui at a 95 % level of confidence, both expressed in ng/kg.
Results given in absolute values.
CCQM-K156
MEASURAND L-PFOS in ground water
NOMINAL VALUE 4 ng/kg
Degrees of equivalence represented by Di = (xI - xR) / xR and its expanded relative uncertainty Ui at a 95 % level of confidence, both expressed in %.
Results given in relative values.
CCQM-K156
MEASURAND L-PFOA in ground water
NOMINAL VALUE 5 ng/kg
Degrees of equivalence represented by Di = (xI - xR) and its expanded uncertainty Ui at a 95 % level of confidence, both expressed in ng/kg.
| LABi | Di | Uneg,i | Upos,i | |
|---|---|---|---|---|
ng/kg |
ng/kg |
ng/kg |
||
| BAM | -2.2 | 1.1 | ||
| NMIA | -0.28 | 0.91 | ||
| GL | -0.22 | 1.7 | ||
| UME | -0.21 | 0.95 | ||
| SYKE | -0.12 | 1.2 | ||
| NIM | 0.48 | 1.6 | ||
| VNIIM | 0.57 | 0.93 |
Results given in absolute values.
CCQM-K156
MEASURAND L-PFOA in ground water
NOMINAL VALUE 5 ng/kg
Degrees of equivalence represented by Di = (xI - xR) / xR and its expanded relative uncertainty Ui at a 95 % level of confidence, both expressed in %.
| LABi | Di | Uneg,i | Upos,i | |
|---|---|---|---|---|
% |
% |
% |
||
| BAM | -45 | 22 | ||
| NMIA | -5.7 | 19 | ||
| GL | -4.5 | 35 | ||
| UME | -4.3 | 19 | ||
| SYKE | -2.5 | 25 | ||
| NIM | 10 | 33 | ||
| VNIIM | 12 | 19 |
Results given in relative values.
CCQM-K156
MEASURAND L-PFOS in ground water
NOMINAL VALUE 4 ng/kg
Degrees of equivalence represented by Di = (xI - xR) and its expanded uncertainty Ui at a 95 % level of confidence, both expressed in ng/kg.
| LABi | Di | Uneg,i | Upos,i | |
|---|---|---|---|---|
ng/kg |
ng/kg |
ng/kg |
||
| VNIIM | -1.8 | 0.78 | ||
| BAM | -0.43 | 0.84 | ||
| UME | -0.11 | 0.89 | ||
| GL | 0.12 | 1.3 | ||
| NMIA | 0.15 | 0.81 | ||
| NIM | 0.17 | 1.4 | ||
| SYKE | 0.66 | 1.1 |
Results given in absolute values.
CCQM-K156
MEASURAND L-PFOS in ground water
NOMINAL VALUE 4 ng/kg
Degrees of equivalence represented by Di = (xI - xR) / xR and its expanded relative uncertainty Ui at a 95 % level of confidence, both expressed in %.
| LABi | Di | Uneg,i | Upos,i | |
|---|---|---|---|---|
% |
% |
% |
||
| VNIIM | -47 | 21 | ||
| BAM | -11 | 22 | ||
| UME | -2.9 | 23 | ||
| GL | 3.2 | 34 | ||
| NMIA | 4.0 | 21 | ||
| NIM | 4.5 | 37 | ||
| SYKE | 17 | 29 |
Results given in relative values.
| Metrology area, Sub-field | Chemistry and Biology, Organics |
| Description | Perfluorinated contaminants in water |
| Time of measurements | 2018 - 2019 |
| Status | Approved for equivalence |
| Final Reports of the comparisons | |
| Measurand | Mass fraction of L-PFOA and L-PFOS in ng/kg |
| Transfer device | Samples |
| Comparison type | Key Comparison |
| Consultative Committee | CCQM (Consultative Committee for Amount of Substance) |
| Conducted by | CCQM (Consultative Committee for Amount of Substance) |
| Pilot institute |
UME
TÜBITAK Ulusal Metroloji Enstitüsü Türkiye |
| Contact person | Mine Bilsel |
| Pilot laboratory | |
|---|---|
| UME |
TÜBITAK Ulusal Metroloji Enstitüsü, Türkiye, EURAMET |
| BAM |
Bundesanstalt für Materialforschung und -prüfung, Germany, EURAMET |
| GL |
Government Laboratory, Hong Kong, China, APMP |
| MIKES-SYKE |
Finnish Environment Institute, Finland, EURAMET |
| NIM |
National Institute of Metrology, China, APMP |
| NMIA |
National Measurement Institute, Australia, Australia, APMP |
| VNIIM |
D.I. Mendeleyev Institute for Metrology, Rosstandart, Russian Federation, COOMET |
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CCQM-K156
MEASURAND L-PFOA in ground water
NOMINAL VALUE 5 ng/kg
The key comparison reference value xR and its associated standard uncertainty uR are computed using a hierarchical Bayesian random effects model of the reported results.
xR = 4.9 ng/kg uR = 0.4 ng/kg
The degree of equivalence of laboratory i relative to the key comparison reference value xR is given by a pair of terms, both expressed in ng/kg, where
Di = (xi - xR) and its expanded uncertainty Ui at a 95 % level of confidence where Ui = k ui , k representing the coverage factor to obtain 95 % level of confidence.
The degree of equivalence is also given in relative terms by Di = (xI - xR) /xR and its relative expanded uncertainty Ui at a 95 % level of confidence, both expressed in %.
CCQM-K156
MEASURAND L-PFOS in ground water
NOMINAL VALUE 4 ng/kg
The key comparison reference value xR and its associated standard uncertainty uR are computed using a hierarchical Bayesian random effects model of the reported results.
xR = 3.8 ng/kg uR = 0.4 ng/kg
The degree of equivalence of laboratory i relative to the key comparison reference value xR is given by a pair of terms, both expressed in ng/kg, where
Di = (xi - xR) and its expanded uncertainty Ui at a 95 % level of confidence where Ui = k ui , k representing the coverage factor to obtain 95 % level of confidence.
The degree of equivalence is also given in relative terms by Di = (xI - xR) /xR and its relative expanded uncertainty Ui at a 95 % level of confidence, both expressed in %.
CCQM-K156
MEASURAND L-PFOA in ground water
NOMINAL VALUE 5 ng/kg
xi measured mass fraction reported by laboratory i, Labi
ui combined standard uncertainty of xi
ki coverage factor reported by laboratory i
Ui expanded uncertainty of xi at 95 % level of confidence where Ui = kiui
| Labi | xi | u (xi) | u (xi) | ki | U (xi) | U (xi) | |
| ng/kg | ng/kg | % | ng/kg | % | |||
| BAM | 2.749 | 0.359 | 13 | 2 | 0.717 | 26 | |
| NMIA | 4.65 | 0.08 | 1.8 | 2.36 | 0.19 | 4 | |
| GL | 4.71 | 0.72 | 15 | 2 | 1.43 | 30 | |
| UME | 4.72 | 0.19 | 4.0 | 2 | 0.38 | 8 | |
| SYKE | 4.81 | 0.41 | 8.5 | 2 | 0.82 | 17 | |
| NIM | 5.41 | 0.72 | 13 | 2 | 1.44 | 27 | |
| VNIIM | 5.50 | 0.17 | 3.2 | 2 | 0.35 | 6 | |
CCQM-K156
MEASURAND L-PFOS in ground water
NOMINAL VALUE 4 ng/kg
xi measured mass fraction reported by laboratory i, Labi
ui combined standard uncertainty of xi
ki coverage factor reported by laboratory i
Ui expanded uncertainty of xi at 95 % level of confidence where Ui = kiui
| Labi | xi | u (xi) | u (xi) | ki | U (xi) | U (xi) | |
| ng/kg | ng/kg | % | ng/kg | % | |||
| VNIIM | 2.04 | 0.07 | 3.4 | 2 | 0.14 | 7 | |
| BAM | 3.36 | 0.12 | 3.6 | 2 | 0.24 | 7 | |
| UME | 3.68 | 0.20 | 5.0 | 2 | 0.39 | 11 | |
| GL | 3.91 | 0.50 | 14.0 | 2 | 1.0 | 26 | |
| NMIA | 3.94 | 0.08 | 1.9 | 2.31 | 0.17 | 4 | |
| NIM | 3.96 | 0.58 | 15 | 2 | 1.2 | 29 | |
| SYKE | 4.45 | 0.38 | 8.5 | 2 | 0.76 | 17 | |
