Total Amino Acid Composition - dla-lvu.de Reports 2015/Report DLA 42-2015 Total Amino... · From 11...

May 2016 DLA 42/2015 - Total Amino Acid Composition

DLADienstleistung

LebensmittelAnalytik GbR

Evaluation Reportproficiency test

DLA 42/2015

Total Amino Acid Composition

in Infant Food

Dienstleistung Lebensmittel Analytik GbRWaldemar-Bonsels-Weg 17022926 Ahrensburg, Germany

[email protected] www.dla-lvu.de

Coordinator of this PT: Dr. Matthias Besler

Reprint, also in part, only with written permission from DLA-Ahrensburg of 61


Inhalt / Content1. Introduction.........................................................32. Realisation..........................................................3

2.1 Test material...................................................32.1.1 Homogeneity....................................................42.2 Test.............................................................42.3 Submission of results............................................4

3. Evaluation...........................................................53.1 Assigned value...................................................53.2 Standard deviation...............................................53.3 Outliers.........................................................53.4 Target standard deviation........................................53.4.1 General model (Horwitz)........................................63.4.2 Value by precision experiment..................................63.4.3 Value by perception............................................83.5 z-Score..........................................................83.6 z'-Score.........................................................83.7 Quotient ........................................................93.8 Standard uncertainty.............................................9

4. Results.............................................................104.1 L-Alanine in g/100g.............................................114.2 L-Arginine in g/100g............................................134.3 L-Aspartic Acid in g/100g.......................................154.4 L-Cyst(e)ine in g/100g..........................................174.5 L-Glutaminic Acid in g/100g.....................................194.6 Glycine in g/100g...............................................214.7 L-Histidine in g/100g...........................................234.8 L-Isoleucine in g/100g..........................................254.9 L-Leucine in g/100g.............................................274.10 L-Lysine in g/100g.............................................294.11 L-Methionine in g/100g.........................................314.12 L-Phenylalanine in g/100g......................................334.13 L-Proline in g/100g............................................354.14 L-Serine in g/100g.............................................374.15 L-Threonine in g/100g..........................................394.16 L-Tryptophan in g/100g.........................................414.17 L-Tyrosine in g/100g...........................................434.18 L-Valine in g/100g.............................................45

5. Documentation.......................................................475.1 Primary data....................................................475.2 Homogeneity.....................................................525.3 Analytical Methods..............................................53

6. Index of participant laboratories...................................607. Index of references.................................................61



1. Introduction

The participation in proficiency testing schemes is an essential elementof the quality-management-system of every laboratory testing food andfeed, cosmetics and food contact materials. The implementation ofproficiency tests enables the participating laboratories to prove theirown analytical competence under realistic conditions. At the same timethey receive valuable data regarding the validity of the particulartesting method. The purpose of DLA is to offer proficiency tests for selected parametersin concentrations with practical relevance.Realisation and evaluation of the present proficiency test follows thetechnical requirements of DIN EN ISO/IEC 17043 (2010) and DIN ISO13528:2009 (6).

2. Realisation

2.1 Test material

The test material is a common in commerce infant food formula based onwhey proteins with < 20% protein content from a EU supplier. The powderwas mixed and homogenized. Afterwards the samples were packagedlightproof in portions to approximately 10 g. The portions were numberedchronologically.

The composition (list of ingredients) of the samples is given in table 1.

Table 1: Composition of DLA-Samples

Infant Food Milk Formula

Ingredients: Demineralized whey powder, vegetable oils, lactose, skimmed milk powder, galacto-oligosaccharides (from milk), whey protein concentrate, fructo-oligosaccharides, calcium carbonate, potassium citrate, potassium chloride, fish oil, magnesium chloride, calcium phosphate, vitamin C, soylecithin, cholin chloride, taurine, nucleotides (uridine-, cytidine-, adenosine-, inosin-, guanosin-5-monophosphate),iron sulfate, vitamin E, zinc sulfate, inositol, niacin, L-tryptophan, L-carni-tin, calcium-D-pantothenate, folic acid, copper sulfate, vitamin A, biotin, vit-amin B12, vitamin B1, vitamin D3, vitamin B6, manganese sulfate, potassium iodi-de, vitamin K1, sodium selenite

Nutrients per 100 g: protein 9,7 g, carbohydrates 54 g thereof sugar 53 g, fat 25 g



2.1.1 Homogeneity

Homogeneity of the test material was checked by 5fold determination ofmagnesium by ICP-OES. With a repeatability standard deviation of 2,3 %the homogeneity of the test material was considered acceptable. The re-sults are given in the documentation.

The calculation of the repeatability standard deviation of the partici-pants was also used as an indicator of homogeneity. For L-lysine it was2,6 % and for L-threonine 2,4 % and in the range of common relative re-peatability standard deviations of methods for amino acid determination(13-16). The repeatability standard deviation of the participants forboth parameters is given in the documentation.

Additionally in the documentation the portion numbers are graphically as-signed to the results of L-alanine. There is no trend recognizable in theresults which could suggest inhomogeneity.

2.2 Test

Two portions of test material were sent to every participating laboratoryin the 40th week of 2015. The testing method was optional. The testsshould be finished at 13th November 2015.

2.3 Submission of results

The participants submitted their results in provided standard forms byemail.The final concentration of the parameters as mean of both numberedsamples (as far as available) was used for each statistical evaluation. Queried and documented were single results, recovery and the testingmethods used. From 11 participants of the PTs total amino acid composition (DLA42/2015) and free amino acids (DLA 43/2015) 7 and 9 participantssubmitted results, respectively. One participant submitted no results.All other participants submitted their results in time.


http://dict.leo.org/ende?lp=ende&p=/gQPU.&search=inhomogeneity

http://dict.leo.org/ende?lp=ende&p=/gQPU.&search=retrieval


3. Evaluation

3.1 Assigned value

Because the analysed material was no certified reference material therobust mean of the submitted results was used as assigned value X (6).The distribution of submitted results showed no hint for bimodaldistribution or other reasons for a higher variability.The statistical evaluation is performed when there are at least 7 resultsfor a parameter.This was the case for all parameters except for cysteine/cystine andtryptophan. Therefore for the parameters cysteine/cystine and tryptophanno statistical evaluation was done.Single results giving values outside the measuring range of theparticipating laboratory were considered for statistical evaluation (e.g.results given as > 25 mg/kg and < 2,5 mg/kg, respectively) when a resultindicating „>“ is above and a result indicating „<“ is below the targetrange.

3.2 Standard deviation

For comparison to the target standard deviation a robust standard devi-ation (Sx) was calculated (6).

3.3 Outliers

Statistical outliers were determined by Mandel´s-H-Statistic for 95%significance niveau (5). Detected outliers were stated for informationonly, when z-score was < -2 or > 2.

3.4 Target standard deviation

The target standard deviation of the assigned value is determinedaccording to the following methods.

In general the Horwitz target standard deviation is suitable for thestatistical evaluation of interlaboratory tests where differentanalytical methods are applied. The standard deviation from precisionexperiments are derived from proficiency tests where a specificanalytical method is mandatory. For information the z-scores from bothmodels were given in the result tables, if available.

For the valuation of the following parameters the target standard devia-tion according to the general model of horwitz was applied (3.4.1): L-alanine, L-arginine, glycine, L-isoleucine, L-leucine, L-lysine, L-phe-nylalanine, L-serine, L-threonine and L-valine.

For the valuation of the following parameters the target standard devia-tion from precision experiments (s. 3.4.2) (German official ASU §64 me-



thod: 14) was applied: L-aspartic acid, L-glutaminic acid, L-histidine,L-methionine, L-proline and L-tyrosine.

Additionally the standard uncertainty was considered for L-arginine andL-serine and for L-histidine and L-tyrosine, respectively, by valuatingwith z'-score (see 3.6).

For L-cysteine/L-cystine and L-tryptophan there were < 7 quantitativeresults, thus no statistical evaluation could be done

3.4.1 General model (Horwitz)

The relative target standard deviation in % of the assigned value isderived from following equation (Horwitz)

σ (%) = 2(1-0,5logX)

From the result the target standard deviation is calculated

σ = X * σ (%) / 100.

3.4.2 Value by precision experiment

Using the reproducibility standard deviation σR and the repeatabilitystandard deviation σr of a precision experiment the between-laboratoriesstandard deviation can be calculated σL :

L= R2− r

2 .

And then, using the number of replicate measurements n, each participantis to perform, the target standard deviation for proficiency assessmentis calculated :

= L2 r

2/n .

The target standard deviations given in table 2 were calculated from theprecision data of the respective methods.



Table 2: Relative target standard deviations (RSD) according to precisionexperiments (14, 15, 16)

Parameter Matrix RSD σ Method / Literature

L-Alanine Dietetic food 4,7 % 1 ASU §64 L 49.07-2 (14)

L-Arginine Dietetic food 6,6 % 1 ASU §64 L 49.07-2 (14)

L-Aspartic acid Dietetic food 7,3 % 1 ASU §64 L 49.07-2 (14)

L-Cyst(e)ine Dietetic foodProtein concentrate

14,2 % 1

12,1 %ASU §64 L 49.07-2 (14)VO 152/2009/EG (16)

L-Glutaminic acid Dietetic food 4,8 % 1 ASU §64 L 49.07-2 (14)

Glycine Dietetic food 6,5 % 1 ASU §64 L 49.07-2 (14)

L-Histidine Dietetic food 10,6 % 1 ASU §64 L 49.07-2 (14)

L-Isoleucine Dietetic food 4,9 % 1 ASU §64 L 49.07-2 (14)

L-Methionine Dietetic foodProtein concentrate

6,1 % 1

12,9 %ASU §64 L 49.07-2 (14)VO 152/2009/EG (16)

L-Leucine Dietetic food 5,3 % 1 ASU §64 L 49.07-2 (14)

L-Lysine Dietetic foodProtein concentrate

8,8 % 1

2,2 %ASU §64 L 49.07-2 (14)VO 152/2009/EG (16)

L-Phenylalanine Dietetic food - ASU §64 L 49.07-2 (14)

L-Proline Dietetic food 7,7 % 1 ASU §64 L 49.07-2 (14)

L-Serine Dietetic food 4,2 % 1 ASU §64 L 49.07-2 (14)

L-Threonine Dietetic foodProtein concentrate

5,5 % 1

3,0 %ASU §64 L 49.07-2 (14)VO 152/2009/EG (16)

L-Tryptophan Dietetic food 6,8 % 1 ASU §64 L 49.07-3 (15)

L-Tyrosine Dietetic food 6,5 % 1 ASU §64 L 49.07-2 (14)

L-Valine Dietetic food 5,8 % 1 ASU §64 L 49.07-2 (14)1 values given/applied in the evaluation (s. chapter 4)



3.4.3 Value by perception

The target standard deviation for proficiency assessment can be set at avalue that corresponds to the level of performance that the coordinatorwould wish laboratories to be able to achieve (6).

For the present evaluation of results the target standard deviation ac-cording to Horwitz was applied for L-alanine, L-arginine, glycine, L-i-soleucine, L-leucine, L-lysine, L-phenylalanine, L-serine, L-threonine and L-valine (3.4.1) and the target standard deviation from precision experiments was applied for L-aspartic acid, L-glutaminic acid, L-histi-dine, L-methionine, L-proline and L-tyrosine (3.4.2).

Additionally the standard uncertainty was considered for L-arginine andL-serine and for L-histidine and L-tyrosine, respectively, by valuatingwith z'-score (see 3.6).

3.5 z-Score

To assess the results of the participants the z-score is used. Itindicates about which multiple of the target standard deviation ( σ )the result (x) of the participant is deviating from the assigned value(X) (6).Participants’ z-scores were derived as:

z = (x – X) / σ ;

the requirements for the analytical performance are generally consideredas fulfilled if

-2 ≤ z ≤ 2 .

3.6 z'-Score

The z'-score can be used for the valuation of the results of theparticipants, in cases the standard uncertainty has to be considered (s.3.8). The z'-score represents the relation of the deviation of the result(x) of the participant from the respective assigned value (X) to thesquare root of quadrat sum of the target standard deviation ( σ̂ ) andthe standard uncertainty (Ux) (6).

Participants’ z'-scores are derived as:

In the following we define the denominator as the target standarddeviation σ '.

The requirements for the analytical performance are generally considered



as fulfilled if

-2 ≤ z' ≤ 2 .

The z'-Score was used for the analytes L-arginine, L-serine, L-histidineand L-tyrosine by valuating with z'-score (see also 3.7 and 3.8).

3.7 Quotient S x /

Following the Horrat-value the results of a proficiency-test (PT) can beconsidered convincing, if the quotient of robust standard deviation andtarget standard deviation does not exceed the value of 2.A value > 2 means an insufficient precision, i.e. the analytical methodis too variable, or the variation between the test participants is higherthan estimated. Thus the comparability of the results is not given (11).In the present proficiency tests the quotients Sx/ σ̂ were

In the present proficiency test the quotient Sx/ σ̂ of all parametersexcept L-arginine, L-serine, L-histidine and L-tyrosine was below 2,0.For L-arginine, L-serine, L-histidine and L-tyrosine the quotients Sx/ σ̂were clearly above 2,0. Therefore evaluation of these parameters wasdone according to 3.6 by z'-Scores. The resulting quotients Sx/ σ̂ ' werebelow 2,0 then.

3.8 Standard uncertainty

The assigned value X has a standard uncertainty u X that depends on theanalytical method, differences between the analytical methods used, thetest material, the number of participant laboratories and perhaps onother factors. The standard uncertainty u X for this PT is calculatedas follows (6).

u X=1,25∗S x / p

If u X ≤ 0,3∗ the standard uncertainty of the assigned value needsnot to be included in the interpretation of the results of the PT (6).Values exceeding 0,3 imply, that the target standard deviation could betoo low with respect to the standard uncertainty of the assigned value.

In the present proficiency tests the quotients Ux/ σ̂ were for allparameters except L-arginine, L-serine, L-histidine and L-tyrosinebetween 0,26 and 0,74. For L-arginine, L-serine, L-histidine and L-tyrosine the quotients were between 1,2 and 1,5. At the same time thequotients Sx/ σ̂ were > 2,0 for L-arginine, L-serine, L-histidine and L-tyrosine. Therefore the target range for these parameters was extendedaccording 3.6 z'-score considering the standard uncertainty.



4. Results

All following tables are anonymized. With the delivering of theevaluation-report the participants are informed about their individualevaluation-number. In the first table the characteristics are listed:

Statistic Data

Number of results

Number of outliers

Mean

Median

Robust mean (X)

Robust standard deviation (Sx)

Target range:

Target standard deviation σ̂ or σ̂ '

Target standard deviation for information

lower limit of target range (X - 2 σ̂ ) or (X - 2 σ ') *

upper limit of target range (X + 2 σ ) or (X + 2 σ ') *

Quotient Sx/ σ '

Standard uncertainty uX

Quotient u X / '

Number of results in the target range

* Target range is calculated with z-score or z'-score

In the second table the individual results of the participatinglaboratories are listed:


z-Score Hinweis

Remark

Auswerte- nummer Parameter

[Einheit / Unit]

Abweichung [Einheit / Unit]

z-Score (Info)

Evaluation number

Deviation [Einheit / Unit]

σ̂


4.1 L-Alanine in g/100g

Vergleichsuntersuchung / Proficiency Test

Abb. 1: Ergebnisse L-AlaninFig. 1: Results L-Alanine


Statistic DataNumber of results 7Number of outliers 1Mean 0,436Median 0,430Robust Mean (X) 0,432

0,0150Target range:Target standard deviation 0,0196

0,0203

lower limit of target range 0,393upper limit of target range 0,472

0,77

0,00711

0,36

Results in the target range 6Percent in the target range 86


Target standard deviation ASU (for Information)

Quotient Sx/ Standard uncertainty ux

Quotient ux /

σ̂

σ̂

σ̂

1 2 3 4 5 6 7

0,00

0,10

0,20

0,30

0,40

0,50

0,60

0,70

0,80

Ergebnisse / Results

L-Alanin / L-Alanine [g/100g]

obere Grenze upper limit

rob. Mittelwert robust mean

untere Grenze lower limit

Auswertenummer / evaluation number


Ergebnisse der teilnehmenden Institute:Results of Participants:

Abb. 2: Z-Scores L-AlaninFig. 2: Z-Scores L-Alanine


4 7 2 5 1 3 6-3

-2

-1

0

1

2

3

z-Score


z-Score Hinweis

Remark

1 0,432 -0,0004 0,0 0,02 0,43 -0,0024 -0,1 -0,13 0,4425 0,0101 0,5 0,54 0,413 -0,0194 -1,0 -1,05 0,43 -0,0024 -0,1 -0,16 0,48 0,0476 2,4 2,3 Ausreisser / Outlier

7 0,4245 -0,0079 -0,4 -0,4

Auswerte- nummer

L-Alanin / L-Alanin [g/100g]

Abweichung [g/100g]

z-Score (Info)

Evaluation number

Deviation [g/100g]

σ̂


4.2 L-Arginine in g/100g


Abb. 3: Ergebnisse L-ArgininFig. 3: Results L-Arginine



0,0384Target range:Target standard deviation ' 0,0227

0,0186


1,69

0,0181

0,80




Quotient Sx/ 'Standard uncertainty ux

Quotient ux / '

σ̂

σ̂

σ̂

1 2 3 4 5 6 7

0,00

0,10

0,20

0,30

0,40

0,50

0,60

0,70

0,80


L-Arginin / L-Arginine [g/100g]







Abb. 4: Z'-Scores L-ArgininFig. 4: Z'-Scores L-Arginine


z'-Score Hinweis

Remark

1 0,266 -0,0159 -0,7 -0,92 0,33 0,0481 2,1 2,63 0,23 -0,0519 -2,3 -2,84 0,256 -0,0259 -1,1 -1,45 0,29 0,0081 0,4 0,46 0,31 0,0281 1,2 1,57 0,291 0,0091 0,4 0,5

Auswerte- nummer

L-Arginin / L-Arginine

[g/100g]

Abweichung [g/100g]

z-Score (Info)

Evaluation number

Deviation [g/100g]

σ̂

3 4 1 5 7 6 2-3

-2

-1

0

1

2

3

z'-Score



4.3 L-Aspartic Acid in g/100g


Abb. 5: Ergebnisse L-AsparaginsäureFig. 5: Results L-Aspartic Acid




0,0371


0,55

0,0174

0,26



Target standard deviation Horwitz (for Information)


Quotient ux /

σ̂

σ̂

σ̂

1 2 3 4 5 6 7

0,00

0,20

0,40

0,60

0,80

1,00

1,20

1,40


L-Asparagin-säure / L-Aspartic Acid [g/100g]







Abb. 6: Z-Scores L-AsparaginsäureFig. 6: Z-Scores L-Aspartic Acid


z-Score Hinweis

Remark

1 0,929 0,0137 0,2 0,42 0,91 -0,0053 -0,1 -0,13 0,88 -0,0353 -0,5 -1,04 0,876 -0,0393 -0,6 -1,15 0,91 -0,0053 -0,1 -0,16 1,01 0,0947 1,4 2,67 0,9315 0,0162 0,2 0,4

Auswerte- nummer

L-Asparaginsäure / L-Aspartic Acid

[g/100g]

Abweichung [g/100g]

z-Score (Info)

Evaluation number

Deviation [g/100g]

σ̂

4 3 5 2 1 7 6-3

-2

-1

0

1

2

3

z-Score



4.4 L-Cyst(e)ine in g/100g


Due to the low number of results <7 no statistical evaluation was done.

Abb. 7: Ergebnisse L-CystinFig. 7: Results L-Cystine


1 2 3 4 5 6 7

0,00

0,10

0,20

0,30

0,40

0,50

0,60

0,70

0,80


L-Cystin / L-Cystine [g/100g]

Median



0,0410Target range:Target standard deviation lower limit of target rangeupper limit of target range

Results in the target rangePercent in the target range



Quotient ux /

σ̂

σ̂

σ̂




z-Score Hinweis

Remark

12 0,16 -0,020334 0,141 -0,03935 0,2 0,01986 0,22 0,03987

Auswerte- nummer

L-Cystin / L-Cystine [g/100g]

Abweichung [g/100g]

z-Score (Info)

Evaluation number

Deviation [g/100g]

σ̂


4.5 L-Glutaminic Acid in g/100g


Abb. 8: Ergebnisse L-GlutaminsäureFig. 8: Results L-Glutaminic Acid


1 2 3 4 5 6 7

0,00

0,50

1,00

1,50

2,00

2,50


L-Glutamin-säure / L-Glutaminic Acid [g/100g]







0,0692


1,4

0,0587

0,64





Quotient ux /

σ̂

σ̂

σ̂



Abb. 9: Z-Scores L-GlutaminsäureFig. 9: Z-Scores L-Glutaminic Acid


z-Score Hinweis

Remark

1 1,977 0,0711 0,8 1,02 1,88 -0,0259 -0,3 -0,43 1,75 -0,156 -1,7 -2,34 1,804 -0,102 -1,1 -1,55 1,94 0,0341 0,4 0,56 2,08 0,174 1,9 2,57 1,91 0,0041 0,0 0,1

Auswerte- nummer

L-Glutaminsäure / L-Glutaminic Acid

[g/100g]

Abweichung [g/100g]

z-Score (Info)

Evaluation number

Deviation [g/100g]

σ̂

3 4 2 7 5 1 6-3

-2

-1

0

1

2

3

z-Score



4.6 Glycine in g/100g


Abb. 10: Ergebnisse GlycinFig. 10: Results Glycine




0,0125


1,2

0,00548

0,56




Quotient Sx/ Standard uncertainty u

x

Quotient ux /

σ̂

σ̂

σ̂

1 2 3 4 5 6 7

0,00

0,05

0,10

0,15

0,20

0,25

0,30

0,35

0,40


Glycin / Glycine [g/100g]







Abb. 11: Z-Scores GlycinFig. 11: Z-Scores Glycine


z-Score Hinweis

Remark

1 0,199 0,0082 0,8 0,72 0,19 -0,0008 -0,1 -0,13 0,177 -0,0138 -1,4 -1,14 0,183 -0,0078 -0,8 -0,65 0,19 -0,0008 -0,1 -0,16 0,23 0,0392 4,0 3,1 Ausreisser / Outlier

7 0,1885 -0,0023 -0,2 -0,2

Auswerte- nummer

Glycin / Glycine [g/100g]

Abweichung [g/100g]

z-Score (Info)

Evaluation number

Deviation [g/100g]

σ̂

3 4 7 2 5 1 6-3

-2

-1

0

1

2

3

4

5

z-Score



4.7 L-Histidine in g/100g


Abb. 12: Ergebnisse L-HistidinFig. 12: Results L-Histidine




0,0122


1,6

0,0313

0,77




Quotient Sx/ 'Standard uncertainty u

x

Quotient ux / '

σ̂

σ̂

σ̂

1 2 3 4 5 6 7

0,00

0,05

0,10

0,15

0,20

0,25

0,30

0,35

0,40


L-Histidin / L-Histidine [g/100g]







Abb. 13: Z'-Scores L-HistidinFig. 13: Z'-Scores L-Histidine


z'-Score Hinweis

Remark

1 0,326 0,0797 2,0 6,62 0,2 -0,0463 -1,1 -3,83 0,205 -0,0413 -1,0 -3,44 0,212 -0,0343 -0,8 -2,85 0,22 -0,0263 -0,6 -2,26 0,36 0,1137 2,8 9,37 0,2255 -0,0208 -0,5 -1,7

Auswerte- nummer

L-Histidin / L-Histidine [g/100g]

Abweichung [g/100g]

z-Score (Info)

Evaluation number

Deviation [g/100g]

σ̂

2 3 4 5 7 1 6-3

-2

-1

0

1

2

3

z'-Score



4.8 L-Isoleucine in g/100g


Abb. 14: Ergebnisse L-IsoleucinFig. 14: Results L-Isoleucine




0,0266


1,2

0,0130

0,55





x

Quotient ux /

σ̂

σ̂

σ̂

1 2 3 4 5 6 7

0,00

0,10

0,20

0,30

0,40

0,50

0,60

0,70

0,80


L-Isoleucin / L-Isoleucine [g/100g]







Abb. 15: Z-Scores L-IsoleucinFig. 15: Z-Scores L-Isoleucine


z-Score Hinweis

Remark

1 0,574 0,0337 1,4 1,32 0,52 -0,0203 -0,9 -0,83 0,515 -0,0253 -1,1 -1,04 0,571 0,0307 1,3 1,25 0,52 -0,0203 -0,9 -0,86 0,54 -0,0003 0,0 0,07 0,542 0,0017 0,1 0,1

Auswerte- nummer

L-Isoleucin / L-Isoleucine

[g/100g]

Abweichung [g/100g]

z-Score (Info)

Evaluation number

Deviation [g/100g]

σ̂

3 2 5 6 7 4 1-3

-2

-1

0

1

2

3

z-Score



4.9 L-Leucine in g/100g


Abb. 16: Ergebnisse L-LeucinFig. 16: Results L-Leucine




0,0543


0,95

0,0184

0,45





x

Quotient ux /

σ̂

σ̂

σ̂

1 2 3 4 5 6 7

0,00

0,20

0,40

0,60

0,80

1,00

1,20

1,40


L-Leucin / L-Leucine [g/100g]







Abb. 17: Z-Scores L-LeucinFig. 17: Z-Scores L-Leucine


z-Score Hinweis

Remark

1 1,032 0,0109 0,3 0,22 0,99 -0,0311 -0,8 -0,63 0,965 -0,0561 -1,4 -1,04 1,011 -0,0101 -0,2 -0,25 1,05 0,0289 0,7 0,56 1,06 0,0389 1,0 0,77 1,04 0,0189 0,5 0,3

Auswerte- nummer

L-Leucin / L-Leucine [g/100g]

Abweichung [g/100g]

z-Score (Info)

Evaluation number

Deviation [g/100g]

σ̂

3 2 4 1 7 5 6-3

-2

-1

0

1

2

3

z-Score



4.10 L-Lysine in g/100g


Abb. 18: Ergebnisse L-LysinFig. 18: Results L-Lysine




0,0718


1,6

0,0250

0,74





Quotient ux /

σ̂

σ̂

σ̂

1 2 3 4 5 6 7

0,00

0,20

0,40

0,60

0,80

1,00

1,20

1,40


L-Lysin / L-Lysine [g/100g]







Abb. 19: Z-Scores L-LysinFig. 19: Z-Scores L-Lysine


z-Score Hinweis

Remark

1 0,875 0,0581 1,7 0,82 0,86 0,0431 1,3 0,63 0,785 -0,0319 -0,9 -0,44 0,765 -0,0519 -1,5 -0,75 0,83 0,0131 0,4 0,26 0,76 -0,0569 -1,7 -0,87 0,843 0,0261 0,8 0,4

Auswerte- nummer

L-Lysin / L-Lysine [g/100g]

Abweichung [g/100g]

z-Score (Info)

Evaluation number

Deviation [g/100g]

σ̂

6 4 3 5 7 2 1-3

-2

-1

0

1

2

3

z-Score



4.11 L-Methionine in g/100g


Abb. 20: Ergebnisse L-MethioninFig. 20: Results L-Methionine




0,0109


0,9

0,00630

0,48





Quotient ux /

σ̂

σ̂

σ̂

1 2 3 4 5 6 7

0,00

0,05

0,10

0,15

0,20

0,25

0,30

0,35

0,40


L-Methionin / L-Methionine [g/100g]







Abb. 21: Z-Scores L-MethioninFig. 21: Z-Scores L-Methionine


z-Score Hinweis

Remark

12 0,21 -0,0053 -0,4 -0,53 0,215 -0,0003 0,0 0,04 0,222 0,0067 0,5 0,65 0,22 0,0047 0,4 0,46 0,19 -0,0253 -1,9 -2,37 0,228 0,0127 1,0 1,2

Auswerte- nummer

L-Methionin / L-Methionine

[g/100g]

Abweichung [g/100g]

z-Score (Info)

Evaluation number

Deviation [g/100g]

σ̂

6 2 3 5 4 7-3

-2

-1

0

1

2

3

4

5

z-Score



4.12 L-Phenylalanine in g/100g


Abb. 22: Ergebnisse L-PhenylalaninFig. 22: Results L-Phenylalanine



0,0201Target range:Target standard deviation 0,0187lower limit of target range 0,370upper limit of target range 0,445

1,1

0,0095

0,51




x

Quotient ux /

σ̂

σ̂

σ̂

1 2 3 4 5 6 7

0,00

0,10

0,20

0,30

0,40

0,50

0,60

0,70

0,80


L-Phenylalanin / L-Phenyl-alanine [g/100g]







Abb. 23: Z-Scores L-PhenylalaninFig. 23: Z-Scores L-Phenylalanine


z-Score Hinweis

Remark

1 0,392 -0,0158 -0,82 0,42 0,0122 0,73 0,379 -0,0288 -1,54 0,405 -0,0028 -0,15 0,43 0,0222 1,26 0,42 0,0122 0,77 0,4085 0,0007 0,0

Auswerte- nummer

L-Phenylalanin / L-Phenylalanine

[g/100g]

Abweichung [g/100g]

Evaluation number

Deviation [g/100g]

σ̂

3 1 4 7 2 6 5-3

-2

-1

0

1

2

3

z-Score



4.13 L-Proline in g/100g


Abb. 24: Ergebnisse L-ProlinFig. 24: Results L-Proline




0,0311


0,57

0,0156

0,27





x

Quotient ux /

σ̂

σ̂

σ̂

1 2 3 4 5 6 7

0,00

0,20

0,40

0,60

0,80

1,00

1,20

1,40


L-Prolin / L-Proline [g/100g]







Abb. 25: Z-Scores L-ProlinFig. 25: Z-Scores L-Proline


z-Score Hinweis

Remark

1 0,733 -0,0113 -0,2 -0,42 0,77 0,0257 0,4 0,83 0,725 -0,0193 -0,3 -0,64 0,662 -0,0823 -1,4 -2,65 0,75 0,0057 0,1 0,26 0,78 0,0357 0,6 1,17 0,757 0,0127 0,2 0,4

Auswerte- nummer

L-Prolin / L-Proline

[g/100g]

Abweichung [g/100g]

z-Score (Info)

Evaluation number

Deviation [g/100g]

σ̂

4 3 1 5 7 2 6-3

-2

-1

0

1

2

3

z-Score



4.14 L-Serine in g/100g


Abb. 26: Ergebnisse L-SerinFig. 26: Results L-Serine




0,0229


1,8

0,0360

0,84





x

Quotient ux / '

σ̂

σ̂

σ̂

1 2 3 4 5 6 7

0,00

0,10

0,20

0,30

0,40

0,50

0,60

0,70

0,80


L-Serin / L-Serine [g/100g]







Abb. 27: Z'-Scores L-SerinFig. 27: Z'-Scores L-Serine


4 1 3 7 5 2 6-3

-2

-1

0

1

2

3

z'-Score


z'-Score Hinweis

Remark

1 0,512 -0,0263 -0,6 -1,12 0,58 0,0417 1,0 1,83 0,52 -0,0183 -0,4 -0,84 0,431 -0,107 -2,5 -4,75 0,55 0,0117 0,3 0,56 0,65 0,112 2,6 4,97 0,525 -0,0133 -0,3 -0,6

Auswerte- nummer

L-Serin / L-Serine [g/100g]

Abweichung [g/100g]

z-Score (Info)

Evaluation number

Deviation [g/100g]

σ̂


4.15 L-Threonine in g/100g


Abb. 28: Ergebnisse L-ThreoninFig. 28: Results L-Threonine




0,0296


0,86

0,0096

0,41





x

Quotient ux /

σ̂

σ̂

σ̂

1 2 3 4 5 6 7

0,00

0,10

0,20

0,30

0,40

0,50

0,60

0,70

0,80


L-Threonin / L-Threonine [g/100g]







Abb. 29: Z-Scores L-ThreoninFig. 29: Z-Scores L-Threonine


z-Score Hinweis

Remark

1 0,532 -0,0034 -0,1 -0,12 0,54 0,0046 0,2 0,23 0,525 -0,0104 -0,4 -0,44 0,493 -0,0424 -1,8 -1,45 0,54 0,0046 0,2 0,26 0,66 0,125 5,3 4,2 Ausreisser / Outlier

7 0,54 0,0046 0,2 0,2

Auswerte- nummer

L-Threonin / L-Threonine

[g/100g]

Abweichung [g/100g]

z-Score (Info)

Evaluation number

Deviation [g/100g]

σ̂

4 3 1 2 5 7 6-3

-2

-1

0

1

2

3>

z-Score



4.16 L-Tryptophan in g/100g


Due to the low number of results <7 no statistical evaluation was done.

Abb. 30: Ergebnisse L-TryptophanFig. 30: Results L-Tryptophan



0,0656Target range:Target standard deviation lower limit of target rangeupper limit of target range

Results in the target rangePercent in the target range



x

Quotient ux /

σ̂

σ̂

σ̂

1 2 3 4 5 6 7

0,00

0,10

0,20

0,30

0,40

0,50

0,60

0,70

0,80


L-Tryptophan [g/100g]

Median





z-Score Hinweis

Remark

1234 0,49 0,299 no method indicated

5 0,15 -0,0409 VDLUFA

6 0,176 -0,015 EU VO 152/2009

7 0,162 -0,0294 no method indicated

Auswerte- nummer

L-Tryptophan [g/100g]

Abweichung [g/100g]

z-Score (Info)

Evaluation number

Deviation [g/100g]

σ̂


4.17 L-Tyrosine in g/100g


Abb. 31: Ergebnisse L-TyrosinFig. 31: Results L-Tyrosine




0,0150


1,7

0,0265

0,79





x

Quotient ux / '

σ̂

σ̂

σ̂

1 2 3 4 5 6 7

0,00

0,10

0,20

0,30

0,40

0,50

0,60

0,70

0,80


L-Tyrosin / L-Tyrosine [g/100g]







Abb. 32: Z'-Scores L-TyrosinFig. 32: Z'-Scores L-Tyrosine


z'-Score Hinweis

Remark

1 0,263 -0,0514 -1,5 -3,42 0,32 0,0056 0,2 0,43 0,255 -0,0594 -1,8 -4,04 0,293 -0,0214 -0,6 -1,45 0,34 0,0256 0,8 1,76 0,42 0,106 3,2 7,1 Ausreisser / Outlier

7 0,3315 0,0171 0,5 1,1

Auswerte- nummer

L-Tyrosin / L-Tyrosine

[g/100g]

Abweichung [g/100g]

z-Score (Info)

Evaluation number

Deviation [g/100g]

σ̂

3 1 4 2 7 5 6-3

-2

-1

0

1

2

3

4

z'-Score



4.18 L-Valine in g/100g


Abb. 33: Ergebnisse L-ValinFig. 33: Results L-Valine




0,0346


1,3

0,0158

0,61





Quotient ux /

σ̂

σ̂

σ̂

1 2 3 4 5 6 7

0,00

0,10

0,20

0,30

0,40

0,50

0,60

0,70

0,80


L-Valin / L-Valine [g/100g]







Abb. 34: Z-Scores L-ValinFig. 34: Z-Scores L-Valine


z-Score Hinweis

Remark

1 0,613 0,0152 0,6 0,42 0,57 -0,0278 -1,1 -0,83 0,585 -0,0128 -0,5 -0,44 0,608 0,0102 0,4 0,35 0,56 -0,0378 -1,5 -1,16 0,74 0,142 5,5 4,1 Ausreisser / Outlier

7 0,601 0,0032 0,1 0,1

Auswerte- nummer

L-Valin / L-Valine [g/100g]

Abweichung [g/100g]

z-Score (Info)

Evaluation number

Deviation [g/100g]

σ̂

5 2 3 7 4 1 6-3

-2

-1

0

1

2

3>

z-Score



5. Documentation

5.1 Primary data


Parameter Teilnehmer Einheit Proben-Nr. A Proben-Nr. B Ergebnis (Mittel) Ergebnis A Ergebnis B inkl. WFAnalyte Participant Unit Sample No. A Sample No. B Result (Mean) Result A Result B incl. RR

1 g/100g 20 35 0,432 0,435 0,428 no2 g/100g 4 37 0,43 0,43 0,42 no no3 g/100g 8 25 0,4425 0,441 0,4444 g/100g 1 17 0,413 0,419 0,4075 g/100g 16 38 0,43 0,43 0,42 no6 g/100g 7 18 0,48 0,48 0,48 no7 g/100g 45 13 0,4245 0,424 0,425



Wiederfindungsrate [%]Recovery rate [%]

L-Alanin / L-Alanine


L-Asparaginsäure / L-Aspartic Acid




1 g/100g 20 352 g/100g 4 37 0,16 0,15 0,16 no no3 g/100g 8 254 g/100g 1 17 0,141 0,144 0,1395 g/100g 16 38 0,2 0,2 0,2 no6 g/100g 7 18 0,22 0,22 0,22 no7 g/100g 45 13


Glycin / Glycine



L-Cystin / L-Cystine

L-Glutaminsäure / L-Glutaminic Acid






1 g/100g 20 35 1,032 1,045 1,02 no2 g/100g 4 37 0,99 1 0,98 no no3 g/100g 8 25 0,965 0,96 0,974 g/100g 1 17 1,011 1,015 1,0075 g/100g 16 38 1,05 1,05 1,04 no6 g/100g 7 18 1,06 1,06 1,06 no7 g/100g 45 13 1,04 1,04 1,04


L-Histidin / L-Histidine


L-Leucin / L-Leucine





1 g/100g 20 352 g/100g 4 37 0,21 0,22 0,2 no no3 g/100g 8 25 0,22 0,21 0,224 g/100g 1 17 0,222 0,225 0,2195 g/100g 16 38 0,22 0,21 0,22 no6 g/100g 7 18 0,19 0,19 0,19 no7 g/100g 45 13 0,228 0,243 0,213



L-Lysin / L-Lysine


L-Phenylalanin / L-Phenylalanine









L-Serin / L-Serine



5.2 Homogeneity

5.2.1 Homogeneity test before the PT

Homogeneity test for magnesium by ICP-OES:

5.2.2 Repeatability standard deviation of duplicate tests of the participants

The repeatability standard deviations were calculated with the data documented in 5.1.It is 0,0209 g/100g = 2,56 % of X for L-lysine.And it is 0,0127 g/100g = 2,38 % of X for L-threonine.

5.2.3 Comparison of sample number / test results


Independant samples mg/100g

1 31,02 31,53 32,04 30,25 30,6

Mean 31,1Repeatability Standard Deviation 0,704 2,3%

0

10

20

30

40

50

60

70

80

90

100

Homgenität / homogeneity


DLA-Nr. / No.

Ergebnis *100


5.3 Analytical Methods

Details by the participants


Parameter Teilnehmer Methodenbeschreibung Einwaage

1 200 - 500 mg Ninhydrin

2 0,5

3 1 g Ninhydrin

4

5 ca. 0,5 g HCl (6 mol/L)

6 REG (EG) 152/2009 0,25g -

7

WF mit gleicher Matrix

Homoge-nisierung

Aufschluss-methode

Derivatisie-rung

Referenzma-terial

Kalibrierver-fahren

Methode ist akkredi-

tiert

Sonstige Hinweise

Analyte ParticipantRecovery with same

matrixMethod description

Homoge-nization

Sample weight

Hydrolization DerivatisationReference material

CalibrationMethod

accreditedFurther remarks


Total amino acids af ter acidic hydroly-sis w ith amino acid analyzer (w ith post-column derivatization)

mortaracidic hydrolysis w ith 6 M HCl, 24 h at 110°C

milk proteinexternal standard, linear regression

yes

no Alanine (total)No- as re-ceived

Yes Yes individual standard Yes Yes

amino acid analyzer acidic hydrolysis infant food one point yes

Amino acids after hydrolysis (accor-ding to REG (EG) 152/2009)

feed (internal RM)internal std., 1-point-calibration

yes

grinding acidic hydrolysis

amino acid stan-dard for protein hydrolysates Sig-ma A2908-5ML

one-point calibrati-on w ith internal standard (norleu-cin)

no

yes




1

2 Arginine (total) 0,5

34567

1

2 0,5

34567

1

2 0,5

345 Oxidation

67


Homoge-nisierung

Aufschluss-methode

Derivatisie-rung

Referenzma-terial

Kalibrierver-fahren


tiert

Sonstige Hinweise



Homoge-nization

Sample weight


CalibrationMethod



noNo- as

receivedYes Yes individual standard Yes Yes

yes

L-Asparaginsäure

/ L-Aspartic Acid

no Aspartic acid (total)No- as


yes

L-Cystin / L-Cystine

no Cystine (total)No- as





1

2 0,5

34567

1

2 Glycine (total) 0,5

34567

1

2 Histidine (total) 0,5

34567


Homoge-nisierung

Aufschluss-methode

Derivatisie-rung

Referenzma-terial

Kalibrierver-fahren


tiert

Sonstige Hinweise



Homoge-nization

Sample weight


CalibrationMethod


L-Glutaminsäure /

L-Glutaminic Acid

no Glutaminc acid (total)No- as


yes

Glycin / Glycine

noNo- as


yes

L-Histidin / L-Histidine

noNo- as


yes




Analyte Participant Method description Hydrolization Derivatisation Calibration

1

2 no Isoleucine (Total) 0,5 Yes Yes individual standard Yes Yes

34567 yes

1

2 no Leucine (total) 0,5 Yes Yes individual standard Yes Yes

34567 yes

1

2 no Lysine (total) 0,5 Yes Yes individual standard Yes Yes

345 Oxidation

67 yes


Homoge-nisierung

Aufschluss-methode

Derivatisie-rung

Referenzma-terial

Kalibrierver-fahren


tiert

Sonstige Hinweise

Recovery with same

matrix

Homoge-nization

Sample weight

Reference material

Method accredited

Further remarks


No- as received

L-Leucin / L-Leucine

No- as received

L-Lysin / L-Lysine

No- as received





1

2 no Methionine (total) 0,5 Yes Yes individual standard Yes Yes

345 Oxidation

67 yes

1

2 no Phenylalanine (total) 0,5 Yes Yes individual standard Yes Yes

34567 yes

1

2 no Proline (total) 0,5 Yes Yes individual standard Yes Yes

34567 yes


Homoge-nisierung

Aufschluss-methode

Derivatisie-rung

Referenzma-terial

Kalibrierver-fahren


tiert

Sonstige Hinweise

Recovery with same

matrix

Homoge-nization

Sample weight

Reference material

Method accredited

Further remarks


No- as received

L-Phenylalanin /

L-Phenylalanine

No- as received


No- as received





1

2 no Serine (total) 0,5 Yes Yes individual standard Yes Yes

34567 yes

1

2 no Threonine (total) 0,5 Yes Yes individual standard Yes Yes

345 Oxidation

67 yes

L-Tryptophan

12 n/a n/a n/a n/a n/a n/a n/a n/a n/a34

5 3-point-calibration ja

67 yes


Homoge-nisierung

Aufschluss-methode

Derivatisie-rung

Referenzma-terial

Kalibrierver-fahren


tiert

Sonstige Hinweise

Recovery with same

matrix

Homoge-nization

Sample weight

Reference material

Method accredited

Further remarks

L-Serin / L-Serine

No- as received


No- as received

HPLC (according to No. 4.11.2 VDLUFA methods III, 2. amendment

1988)




1

2 Tyrosine (total) 0,5

34567

1

2 Valine (total) 0,5

34567


Homoge-nisierung

Aufschluss-methode

Derivatisie-rung

Referenzma-terial

Kalibrierver-fahren


tiert

Sonstige Hinweise



Homoge-nization

Sample weight


CalibrationMethod


L-Tyrosin / L-Tyrosine

noNo- as


yes

L-Valin / L-Valine

noNo- as


yes


6. Index of participant laboratories in alphabetical order

List of participants of PTs DLA 42-2015 and DLA 43-2015:

[Die Adressdaten der Teilnehmer wurden für die allgemeine Veröffentlichung des Auswerte-Berichts nicht angege-ben.]

[The address data of the participants were deleted for publication of the evaluation report.]


ENGLAND

ITALY

DENMARK

SPAIN

NETHERLANDS

Teilnehmer / Participant Ort / Town Land / Country

Germany

Germany

Germany

Germany

Germany

Germany


7. Index of references

1. DIN EN ISO/IEC 17043:2010; Konformitätsbewertung – Allgemeine Anforderun-gen an Eignungsprüfungen / Conformity assessment – General requirements for proficiency testing

2. Verordnung / Regulation 882/2004/EU; Verordnung über amtliche Kontrollen /Regulation on official controls

3. DIN EN ISO/IEC 17025:2005; Allgemeine Anforderungen an die Kompetenz von Prüf- und Kalibrierlaboratorien / General requirements for the competence of testing and calibration laboratories

4. Richtlinie / Directive 1993/99/EU; über zusätzliche Maßnahmen im Bereich der amtlichen Lebensmittelüberwachung / on additional measures concerning the official control of foodstuffs

5. ASU §64 LFGB: Planung und statistische Auswertung von Ringversuchen zur Methodenvalidierung

6. DIN ISO 13528:2009; Statistische Verfahren für Eignungsprüfungen durch Ringversuche / Statistical methods for use in proficiency testing by in-terlaboratory comparisons

7. The International Harmonised Protocol for the Proficiency Testing of Anan-lytical Laboratories ; J.AOAC Int., 76(4), 926 – 940 (1993)

8. The International Harmonised Protocol for the Proficiency Testing of Anan-lytical Chemistry Laboratories ; Pure Appl Chem, 78, 145 – 196 (2006)

9. Evaluation of analytical methods used for regulation of food and drugs;W. Horwitz; Analytical Chemistry, 54, 67-76 (1982)

10.A Horwitz-like funktion describes precision in proficiency test; M. Thomp-son, P.J. Lowthian; Analyst, 120, 271-272 (1995)

11.Protocol for the design, conduct and interpretation of method performance studies; W. Horwitz; Pure & Applied Chemistry, 67, 331-343 (1995)

12.Recent trends in inter-laboratory precision at ppb and sub-ppb concentra-tions in relation to fitness for purpose criteria in proficiency testing; M. Thompson; Analyst, 125, 385-386 (2000)

13.ASU §64 LFGB: L49.07-1; Bestimmung der Aminosäuren in Aminosäurengemi-schen.

14.ASU §64 LFGB: L49.07-2; Bestimmung der Aminosäuren in diätetischen Lebens-mitteln auf Basis von Proteinhydrolysaten

15.ASU §64 LFGB: L49.07-3; Bestimmung des Tryptophangehaltes in diätetischen Lebensmitteln auf Basis von Proteinhydrolysaten

16.Verordnung 152/2009/EG zur Festlegung der Probenahmeverfahren und Analyse-methoden für die amtliche Untersuchung von Futtermitteln / Regulation 152/2009/EC laying down the methods of sampling and analysis for the offi-cial control of feed


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