# Commission Regulation (EC) No 152/2009 of 27 January 2009 laying down the methods of sampling and analysis for the official control of feed (Text with EEA relevance), Division 8: Results of a collaborative study

Extent: E+W+S+N.I.

An EC collaborative study (4th intercomparison) was arranged in which three samples were analysed by up to 12 laboratories to certify the method for hydrolysis. Replicate (5) analyses were performed on each sample. The results are given in the following table:
Sample 1Pig feed
Sample 2Pig feed supplemented with L-tryptophan
Sample 3Feed concentrate for pigs
L
12
12
12
n
50
55
50
Mean [g/kg]
2,42
3,4
4,22
sr [g/kg]
0,05
0,05
0,08
r [g/kg]
0,14
0,14
0,22
CVr [%]
1,9
1,6
1,9
SR [g/kg]
0,15
0,2
0,09
R [g/kg]
0,42
0,56
0,25
CVR [%]
6,3
6,0
2,2
Lnumber of laboratories submitting results
nnumber of single results retained eliminating outliers (identified by Cochran, Dixon outlier test)
sr standard deviation of repeatability
SR standard deviation of reproducibility
rrepeatability
Rreproducibility
CVr coefficient of variation of repeatability, %
CVR coefficient of variation of reproducibility, %
Another EC collaborative study (3rd intercomparison) was arranged in which two samples were analysed by up to 13 laboratories to certify the method for extraction of free tryptophan. Replicate (5) analyses were performed on each sample. The results are given in the following table:
Sample 4Wheat and soya mixture
Sample 5Wheat and soya mixture (= sample 4) with added tryptophan (0,457g/kg1)
L
12
12
n
55
60
Mean [g/kg]
0,391
0,931
sr [g/kg]
0,005
0,012
r [g/kg]
0,014
0,034
CVr [%]
1,34
1,34
SR [g/kg]
0,018
0,048
R [g/kg]
0,05
0,134
CVR [%]
4,71
5,11
Lnumber of laboratories submitting results
nnumber of single results retained after eliminating outliers (identified by Cochran, Dixon outlier test)
sr standard deviation of repeatability
SR standard deviation of reproducibility
rrepeatability
Rreproducibility
CVr coefficient of variation of repeatability, %
CVR coefficient of variation of reproducibility, %
Another EC intercomparison study was arranged in which four samples were analysed by up to 7 laboratories with the aim of a tryptophan certification for hydrolysis. The results are given below. Replicate (5) analyses were performed on each sample.
Sample 1Mixed pig feed(CRM 117)
Sample 2Low fat fish meal(CRM 118)
Sample 3Soybean meal(CRM 119)
Sample 4Skimmed milk powder(CRM 120)
L
7
7
7
7
n
25
30
30
30
Mean [g/kg]
2,064
8,801
6,882
5,236
sr [g/kg]
0,021
0,101
0,089
0,04
r [g/kg]
0,059
0,283
0,249
0,112
CVr [%]
1,04
1,15
1,3
0,76
SR [g/kg]
0,031
0,413
0,283
0,221
R [g/kg]
0,087
1,156
0,792
0,619
CVR [%]
1,48
4,69
4,11
4,22
Lnumber of laboratories submitting results
nnumber of single results retained after eliminating outliers (identified by Cochran, Dixon outlier test)
sr standard deviation of repeatability
SR standard deviation of reproducibility
rrepeatability
Rreproducibility
CVr coefficient of variation of repeatability, %
CVR coefficient of variation of reproducibility, %

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Source: https://www.legislation.gov.uk/eur/2009/152/annex/III/division/G/division/8 (the official version)
Page: https://openlegislation.uk/eu-regulation-2009-152/annex-III/division-G/division-8
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.