In order to classify the datasets in EMPODAT by the quality of data, a scheme has been set up. As such QA/QC relevant metadata are requested to be defined for the datasets, which are then stores in the database. As of the design of the database, a "weight factor" is assigned to each of one of these QA/QC metadata. The scheme assigns "weight" factors from 0 to 10 to the metadata, where the most data quality relevant parameters score 10. The provided metadata are rated according based on the combination of "weight" factor (of the parameter) and their importance for data quality assessment.
| No. |
Metadata |
Information provided |
Rating |
Minimum requirements - category 3 |
Minimum requirements - category 2 |
Minimum requirements - category 1 |
Comment |
| 1 |
Limit of Detection (LoD) |
Filled in |
10 |
10 |
10 |
10 |
Possibility to compare measured value with LoD and set intervals with different scoring |
| Not filled in |
0 |
|
|
|
|
| 2 |
Limit of Quantification (LoQ) |
Filled in |
8 |
|
8 |
8 |
Possibility to compare measured value with LoQ and set intervals with different scoring |
| Not filled in |
0 |
|
|
|
|
| 3 |
Uncertainty at LoQ |
Filled in |
6 |
|
6 |
6 |
|
| Not filled in |
0 |
|
|
|
Score 4 if provided with comment – not at LoQ |
| 4 |
Coverage factor |
Filled in |
2 |
|
|
2 |
|
| Not filled in |
0 |
|
|
|
|
| 5 |
Analytical method |
Filled in |
2 |
|
2 |
2 |
|
| Not filled in |
0 |
|
|
|
|
| 6 |
Sample preparation method |
Filled in |
2 |
|
2 |
2 |
|
| Not filled in |
0 |
|
|
|
|
| 7 |
Has standardised analytical method been used? |
Filled in |
6 |
|
|
|
|
| Not filled in |
0 |
|
|
|
|
| 8 |
Has the used method been validated according to one of the NORMAN protocols? |
V1 – within laboratory |
6 |
6 |
|
|
|
| V2 – between laboratories |
8 |
|
8 |
|
|
| V3 - routine |
10 |
|
|
10 |
|
| No |
0 |
|
|
|
|
| Not known |
0 |
|
|
|
|
| 9 |
Have the results been corrected for extraction recovery? |
Yes |
2 |
|
2 |
2 |
|
| No |
0 |
|
|
|
|
| Not known |
0 |
|
|
|
|
| Not applicable |
2 |
|
|
|
|
| 10 |
Was a field blank checked? |
Yes |
2 |
|
|
2 |
|
| No |
0 |
|
|
|
|
| Not known |
0 |
|
|
|
|
| Not applicable |
2 |
|
|
|
|
| 11 |
Is the laboratory accredited according to ISO 17025? |
Yes |
6 |
|
|
|
|
| No |
0 |
|
|
|
|
| Not known |
0 |
|
|
|
|
| Not applicable |
0 |
|
|
|
|
| 12 |
Is the laboratory accredited for the given determinand? |
Yes |
10 |
|
|
|
|
| No |
0 |
|
|
|
|
| Not known |
0 |
|
|
|
|
| Not applicable |
0 |
|
|
|
|
| 13 |
Does the laboratory participate in interlaboratory studies for the given determinand? |
Yes |
8 |
|
8 |
8 |
|
| No |
0 |
|
|
|
|
| Not known |
0 |
|
|
|
|
| Not applicable |
0 |
|
|
|
|
| 14 |
Summary of performance of the laboratory in interlaboratory studies for given determinand? |
z score < 3 |
10 |
|
|
10 |
The rate of achieving z scores better than 2 in individual PT determinations can form a basis of an additional assessment (90 - 100% Good; 75 - 90% Satisfactory; 50 - 75% Moderate; less than 50% Poor). Ref. How Well Should Laboratories Perform in Proficiency Tests? M.J. Gardner and A.J. Dobbs. J. Environ. Monit., (2004) 6, 559 – 562 |
| z score > 3 |
2 |
|
|
|
|
| Not known |
0 |
|
|
|
|
| Not applicable |
0 |
|
|
|
|
| 15 |
Are control charts recorded for the given determinand? |
Yes |
6 |
6 |
6 |
6 |
Possibility to score according to the number of control points plotted each year |
| No |
0 |
|
|
|
|
| Not known |
0 |
|
|
|
|
| Not applicable |
0 |
|
|
|
|
| 16 |
Are the data controlled by a competent authority (apart from the accreditation body)? |
Yes |
2 |
|
|
|
|
| No |
0 |
|
|
|
|
| Not known |
0 |
|
|
|
|
| Not applicable |
0 |
|
|
|
|
| |
MAXIMUM SCORE |
|
92 |
22 |
52 |
68 |
|
| Score |
Category |
Rank code |
| 68 – 92 |
Adequately supported by quality-related information |
1 |
| 52 – 67 |
Supported by limited quality-related information |
2 |
| 22 – 51 |
Minimal quality-related information |
3 |
| 0 – 21 |
Not supported by quality-related information |
4 |
If any of the minimum requirements for a category do not comply - automatic ranking in lower category
