Division 8 Results of a collaborative study
United Kingdom
A collaborative study was arranged in which 6 feed, 4 premixtures and 3 preparations were analysed by 8 laboratories. Duplicate analyses were performed on each sample. (More detailed information on this collaborative study can be found in the Journal of the AOAC, Volume 71, 1988, p. 484-490). The results (excluding outliers) are shown below:
Table 1
Results of the collaborative study for feed
| Sample 1 | Sample 2 | Sample 3 | Sample 4 | Sample 5 | Sample 6 | |
|---|---|---|---|---|---|---|
| L | 8 | 8 | 8 | 8 | 8 | 8 |
| n | 15 | 14 | 15 | 15 | 15 | 15 |
| Mean (mg/kg) | 50,0 | 47,6 | 48,2 | 49,7 | 46,9 | 49,7 |
| Sr (mg/kg) | 2,9 | 2,69 | 1,38 | 1,55 | 1,52 | 2,12 |
| CVr (%) | 5,8 | 5,6 | 2,9 | 3,1 | 3,2 | 4,3 |
| SR (mg/kg) | 3,92 | 4,13 | 2,23 | 2,58 | 2,26 | 2,44 |
| CVR (%) | 7,8 | 8,7 | 4,6 | 5,2 | 4,8 | 4,9 |
| Nominal content (mg/kg) | 50,0 | 50,0 | 50,0 | 50,0 | 50,0 | 50,0 |
Table 2
Results of the collaborative study for premixtures and preparations
| Premixtures | Preparations | ||||||
|---|---|---|---|---|---|---|---|
| A | B | C | D | A | B | C | |
| L | 7 | 7 | 7 | 7 | 8 | 8 | 8 |
| n | 14 | 14 | 14 | 14 | 16 | 16 | 16 |
| Mean (g/kg) | 8,89 | 9,29 | 9,21 | 8,76 | 94,6 | 98,1 | 104 |
| Sr (g/kg) | 0,37 | 0,28 | 0,28 | 0,44 | 4,1 | 5,1 | 7,7 |
| CVr (%) | 4,2 | 3,0 | 3,0 | 5,0 | 4,3 | 5,2 | 7,4 |
| SR (g/kg) | 0,37 | 0,28 | 0,4 | 0,55 | 5,4 | 6,4 | 7,7 |
| CVR (%) | 4,2 | 3,0 | 4,3 | 6,3 | 5,7 | 6,5 | 7,4 |
| Nominal content (g/kg) | 10,0 | 10,0 | 10,0 | 10,0 | 100 | 100 | 100 |
L
number of laboratories
number of single values
standard deviation of repeatability
coefficient of variation of repeatability
standard deviation of reproducibility
coefficient of variation of reproducibility.