Total Amino Acid Composition

Transcription

1 Proficiency Tests DLA food cosmetics consumer goods Evaluation Report proficiency test DLA 9/0 Total Amino Acid Composition in Dietetic Food as Meal Replacement (Powder Dienstleistung Lebensmittel Analytik GbR Waldemar-Bonsels-Weg 70 9 Ahrensburg, Germany proficiency-testing@dla-lvu.de Coordinator of this PT: Dr. Matthias Besler st Correction 8/0/07: The evaluation of L-Glutamic Acid was replaced, because the first version contained a false data set of participants results. Pages below were changed: - page 0: target standard deviation (now from precision experiment, German ASU - page : characteristic data in table - page 8: last paragraph (L-Glutamic Acid is within 9% to % of amino acid content indicated by the manufacturer - pages 0-: statistical evaluation of L-Glutamic Acid - page 77: figure of kernel density estimation of L-Glutamic Acid Page of 8

2 Allgemeine Informationen zur Eignungsprüfung (EP General Information on the proficiency test (PT EP-Anbieter PT-Provider DLA - Dienstleistung Lebensmittel Analytik GbR Gesellschafter: Dr. Gerhard Wichmann und Dr. Matthias Besler Waldemar-Bonsels-Weg 70, 9 Ahrensburg, Germany EP-Nummer PT-Number EP-Koordinator PT-Coordinator Status des EP-Bericht Status of PT-Report EP-Bericht Freigabe PT-Report Authorization Unteraufträge Subcontractors Tel. ++9(07-97 Fax. ++9( proficiency-testing@dla-lvu.de DLA 9/0 Dr. Matthias Besler Abschlussbericht / Final report (0 December 0. Korrektur / st Correction (8 January 07 Gültig ist die jeweils letzte Version/Korrektur des Berichts. Sie ersetzt alle vorangegangenen Versionen. Only the latest version/correction of the report is valid. It replaces all preceeding versions. Dr. Matthias Besler (Technischer Leiter / Technical Manager - gezeichnet / signed M. Besler Dr. Gerhard Wichmann (QM-Beauftragter / Quality Manager - gezeichnet / signed G. Wichmann Datum / Date: 8 January 07 Die Prüfung der Gehalte, Homogenität und Stabilität von EP-Parametern wird von DLA im Unterauftrag vergeben. The analysis of the content, homogeneity and stability of PT-parameters are subcontracted by DLA. Page of 8

3 Inhalt / Content. Introduction.... Realisation.... Test material..... Homogeneity.... Sample shipment and information to the test...7. Submission of results...7. Evaluation...8. Consensus value from participants (assigned value...8. Robust standard deviation...8. Repeatability standard deviation...8. Reproducibility standard deviation...9. Exclusion of results and outliers...9. Target standard deviation (for proficiency assessment General model (Horwitz..... Value by precision experiment..... Value by perception....7 z-score Warning and action signals....8 z'-score....9 Reproducibility coefficient of variation (CVR....0 Quotient S*/σpt...7. Standard uncertainty...7. Results...8. L-Alanin/L-Alanine in g/00g...0. L-Arginin/L-Arginine in g/00g.... L-Asparaginsäure/L-Aspartic acid in g/00g.... L-Cystein/L-Cysteine in g/00g.... L-Cystin/L-Cystine in g/00g...8. L-Glutaminsäure/L-Glutamic acid in g/00g Glycin/Glycine in g/00g....8 L-Histidin/L-Histidine in g/00g....9 L-Isoleucin/L-Isoleucine in g/00g....0 L-Leucin/L-Leucine in g/00g...8. L-Lysin/L-Lysine in g/00g...0. L-Methionin/L-Methionine in g/00g.... L-Phenylalanin/L-Phenylalanine in g/00g.... L-Prolin/L-Proline in g/00g.... L-Serin/L-Serine in g/00g...8. L-Threonin/L-Threonine in g/00g L-Tryptophan in g/00g....8 L-Tyrosin/L-Tyrosine in g/00g....9 L-Valin/L-Valine in g/00g... Page of 8

4 . Documentation...8. Details by participants Primary data Analytical methods.... Homogeneity Mixture homogeneity before bottling Comparison of sample numbers / test results and trend line...7. Kernel Density Plots of Results...7. Index of participant laboratories Index of references...8 Page of 8

5 . Introduction The participation in proficiency testing schemes is an essential element of the quality-management-system of every laboratory testing food and feed, cosmetics and food contact materials. The implementation of proficiency tests enables the participating laboratories to prove their own analytical competence under realistic conditions. At the same time they receive valuable data regarding the verification and/or validation of the particular testing method [, ]. The purpose of DLA is to offer proficiency tests for selected parameters in concentrations with practical relevance. Realisation and evaluation of the present proficiency test follows the technical requirements of DIN EN ISO/IEC 70 (00 and DIN ISO 8:009 / ISO 8:0 [, ].. Realisation. Test material The test material is a common in commerce dietetic food as a meal replacement (drink powder with a protein content of > 0% based on soyand milkprotein from a EU supplier. The raw materials were sieved by means of a centrifugal mill (mesh 00 µm, mixed and homogenized. Afterwards the samples were portioned to approximately 0 g into metallised PET film bags and chronologically numbered. The composition (list of ingredients and the amounts of amino acids as calculated from the manufacturers specifications are given in table and table respectively. Table : Composition of DLA-Samples Dietetic Drink Powder as Meal Replacement Ingredients: Soy protein isolate (%, honey (0%, skimmed milk powder (%, yoghurt powder (%, maltodextrin, soybean oil, inulin, milk protein, di-potassium phosphate, tri-calcium phosphate, natural flavoring agent, release agent silica, magnesium hydroxide, emulsifier soy lecithins, L-ascorbic acid, iron diphosphate, sweetener steviol glycosides, niacin, DL alpha-tocopherol, zinc oxide, manganese (II sulphate, copper carbonate, calcium D-pantothenate, dye beta carotene, pyridoxine hydrochloride, thiamine mononitrate, riboflavin, retinyl acetate, pteroylmonoglutamic acid, potassium iodide, sodium selenite, D-biotin, cholecalciferol, cyanocobalamin Nutrients per 00 g: Protein g, carbohydrates g thereof sugar 7 g, fat, g Note: The metrological traceability of temperature, mass and volume during production of the PT samples is ensured by DAkkS calibrated reference materials. Page of 8

6 Table : Calculated amounts according to labelled values of vitamins Parameter Content per 00 g Parameter Content per 00 g L-Alanine L-Arginine L-Aspartic acid L-Cysteine L-Glutamic acid Glycine L-Histidine L-Isoleucine L-Leucine,8 g,9 g, g 0,80 g 7,9 g, g, g,0 g, g L-Lysine L-Methionine L-Phenylalanine L-Proline L-Serine L-Threonine L-Tryptophan L-Tyrosine L-Valine,7 g 0, g, g, g,0 g, g 0,0 g, g,0 g.. Homogeneity The mixture homogeneity before bottling was examined 8-fold by microtracer analysis. It is a standardized method that is part of the international GMP certification system for feed []. Before mixing dye coated iron particles of µm size are added to the sample and the number of particles is determined after homogenization in taken aliquots. The evaluation of the mixture homogeneity is based on the Poisson distribution using the chi-square test. A probability of % is equivalent to a good homogeneous mixture and of % to an excellent mixture [, ]. The microtracer analysis of the present PT sample showed a probability of 7%. Additionally particle number results were converted into concentrations, statistically evaluated according to normal distribution and compared to the standard deviation according to Horwitz. This gave a HorRat value of,. The results of microtracer analysis are given in the documentation. The calculation of the repeatability standard deviation S r of the participants was also used as an indicator of homogeneity. It is <,7% (,% -,8% for all analytes except for methionine, tryptophan and valine (,78% -,7%. Therefore the repeatability standard deviations are similar to precision data of the referring standardized methods (e.g. ASU, s... (see Tab. [-9]. The repeatability standard deviations of the participants' results are given in the tables of statistic data (see. to.9. Furthermore, the homogeneity was characterized by the trend line function of participants' results for chronological bottled single samples. The maximum deviation from the mean value of the trend line for alanine and methionine was < 0% of the target standard deviation σpt (s.. homogeneity and can therefore be regarded as low. If the criteria for sufficient homogeneity of the test material are not fulfilled on a particular parameter, the impact on the target standard deviation is checked and optionally the evaluation of the results of the participants will be done using the z'-score considering the standard uncertainty of the assigned value (see.8 and. []. Page of 8

7 . Sample shipment and information to the test Two portions of test material were sent to every participating laboratory in the 7 th week of 0. The testing method was optional. The tests should be finished at 8 th October 0 the latest. With the cover letter along with the sample shipment the following information was given to participants: The two portions contain identical samples of a dietetic food (drink powder as a meal replacement based on soy and milk proteins. The protein content is > 0%. Any suitable method for determination of the analytes can be applied. In general we recommend to homogenize a representative sample amount before analysis according to good laboratory practice, especially in case of low sample weights.. Submission of results The participants submitted their results in standard forms, which have been handed out with the samples (by . The finally calculated concentrations of the parameters as average of duplicate determinations of both numbered samples were used for the statistical evaluation. For the calculation of the repeatability and reproducibility standard deviation the single values of the double determination were used. Queried and documented were single results, recovery and the used testing methods. In case participants submitted several results for the same parameter obtained by different methods these results were evaluated with the same evaluation number with a letter as a suffix and indication of the related method. All 0 participants submitted the result in time. Page 7 of 8

8 . Evaluation. Consensus value from participants (assigned value The robust mean of the submitted results was used as assigned value (X pt ( consensus value from participants providing a normal distribution. The calculation was done according to algorithm A as described in annex C of ISO 8 []. The condition is that the majority of the participants' results show a normal distribution or are distributed unimodal and symmetrically. To this end, an examination of the distribution is carried out, inter alia, using the kernel density estimate [, ]. In case there are indications for sources of higher variability such as a bimodal distribution of results, a cause analysis is performed. Frequently different analytical methods may cause an anomaly in results' distribution. If this is the case, separate evaluations with own assigned values (X pti are made whenever possible. The statistical evaluation is carried out for all the parameters for a minimum of 7 values are present. The actual measurement results will be drafted. Individual results, which are outside the specified measurement range of the participating laboratory (for example with the result > mg/kg or <, mg/kg or the indicating 0 will not be considered for the statistic evaluation [].. Robust standard deviation For comparison to the target standard deviation σpt (standard deviation for proficiency assessment a robust standard deviation (S x was calculated. The calculation was done according to algorithm A as described in annex C of ISO 8 [].. Repeatability standard deviation The repeatability standard deviation Sr is based on the laboratory s standard deviation of (outlier free individual participant results, each under repeatability conditions, that means analyses was performed on the same sample by the same operator using the same equipment in the same laboratory within a short time. It characterizes the mean deviation of the results within the laboratories [] and is used by DLA as an indication of the homogeneity of the sample material. In case single results from participants are available the calculation of the repeatability standard deviation Sr, also known as standard deviation within laboratories Sw, is performed by: [, ]. The relative repeatability standard deviation as a percentage of the mean value is indicated as coefficient of variation CV r in the table of statistical characteristics in the results section in case single results from participants are available. Page 8 of 8

9 . Reproducibility standard deviation The reproducibility standard deviation S R represents a inter-laboratory estimate of the standard deviation for the determination of each parameter on the bases of (outlier free individual participant results. It takes into account both the repeatability standard deviation S r and the within-laboratory standard deviation S S. Reproducibility standard deviations of PT s may differ from reproducibility standard deviations of ring trials, because the participating laboratories of a PT generally use different internal conditions and methods for determining the measured values. In the present evaluation, the specification of the reproducibility standard deviation, therefore, does not refer to a specific method, but characterizes approximately the comparability of results between the laboratories, assumed the effect of homogeneity and stability of the sample are negligible. In case single results from participants are available the calculation of the reproducibility standard deviation S R is performed by: [, ]. The relative reproducibility standard deviation as a percentage of the mean value is indicated as coefficient of variation CV R in the table of statistical characteristics in the results section in case single results from participants are available. Its meaning is explained in more detail in.9.. Exclusion of results and outliers Before statistical evaluation obvious blunders, such as those with incorrect units, decimal point errors, and results for a another proficiency test item can be removed from the data set []. All results should be given at least with significant digits. Specifying significant digits is usually sufficient. Results obtained by different analytical methods causing an increased variability and/or a bi- or multimodal distribution of results, are treated separately or could be excluded in case of too few numbers of results. For this results are checked by kernel density estimation [, ]. Results are identified as outliers by the use of robust statistics. If a value deviates from the robust mean by more than times the robust standard deviation, it is classified as an outlier []. Detected outliers are stated for information only, when z-score are < - or >. Due to the use of robust statistics outliers are not excluded, provided that no other reasons are present []. Page 9 of 8

10 . Target standard deviation (for proficiency assessment The target standard deviation of the assigned value σ pt (= standard deviation for proficiency assessment can be determined according to the following methods. If an acceptable quotient S*/σ pt is present, the target standard deviation of the general model by Horwitz is preferably used for the proficiency assessment. It is usually suitable for for evaluation of interlaboratory studies, where different analytical methods are applied by the participants. On the other hand the target standard deviation from the evaluation of precision data of an precision experiment is derived from collaborative studies with specified analytical methods. In cases where both above-mentioned models are not suitable, the target standard deviation is determined based on values by perception, see under... For information the z-scores of both models are given in the evaluation, if available. In the present PT for valuation of all following parameters the target standard deviation according to the general model of Horwitz was applied (see..: Alanine, Aspartic acid, Glycine, Lysine, Phenylalanine and Serine. For the valuation of the following parameters the target standard deviation from precision experiments (s... (German official ASU method: 7, 8 was applied: Arginine, Cystine, Glutamic acid, Histidine, Isoleucine, Leucine, Methionine, Proline, Threonine, Tryptophan, Tyrosine and Valine. Due to the low number of < 7 the results of Cysteine were not evaluated by means of z-scores. Page 0 of 8

11 .. General model (Horwitz Based on statistical characteristics obtained in numerous PTs for different parameters and methods Horwitz has derived a general model for estimating the reproducibility standard deviation σ R []. Later the model was modified by Thompson for certain concentration ranges [0]. The reproducibility standard deviation σ R can be applied as the relative target standard deviation σpt in % of the assigned values and calculated according to the following equations []. For this the assigned value Xpt is used for the concentration c. Equations Range of concentrations corresponds to σr = 0,c c <, x 0-7 < 0 µg/kg σr = 0,0c 0,89, x 0-7 c 0,8 0 µg/kg σr = 0,0c 0, c > 0,8 >,8 g/00g with c = mass content of analyte (as relative size, e.g. mg/kg = ppm = 0 - kg/kg.. Value by precision experiment Using the reproducibility standard deviation σ R and the repeatability standard deviation σ r of a precision experiment (collaborative trial or proficiency test the target standard deviation σpt can be derived considering the number of replicate measurements m of participants in the present PT []: The values given in Table relative repeatability standard deviation (RSD r and relative reproducibility standard deviation (RSD R were determined in collaborative trials using the specified methods. The in the table indicated resulting target standard deviation σpt is additionally given in the evaluation for information. Page of 8

12 Table : Relative repeatability standard deviations (RSD r and relative reproducibility standard deviations (RSD R from precision experiments and resulting target standard deviations σpt [-9] Parameter Matrix Mean RSD r RSD R σpt Method / Literature L-Alanine Dietetic food,,%,%,9% ASU L-Arginine Dietetic food,8,9%,99%,7% ASU L-Aspartic acid Dietetic food,,9% 7,% 7,% ASU L-Cysteine Dietetic food,,%,%,9% ASU L-Cystine L-Glutamic acid Dietetic food Protein concentrate,07 0,0,%,%,00%,%,%,% ASU VO / 009/EG Dietetic food,7,9%,08%,9% ASU Glycine Dietetic food,0,0%,88%,% ASU L-Histidine Dietetic food,0,7% 0,90% 0,7% ASU L-Isoleucine Dietetic food,9,09%,%,0% ASU L-Methionine Dietetic food Protein concentrate,0,,8%,% 7,9% %,7%,9% ASU VO / 009/EG L-Leucine Dietetic food,09,%,0%,% ASU L-Lysine Dietetic food Protein concentrate L-Phenylalanine,,77,9%,% 8,9%,0% 8,8%,% ASU VO / 009/EG Dietetic food ASU L-Proline Dietetic food,,00% 8,% 7,9% ASU L-Serine Dietetic food,8,%,8%,% ASU L-Threonine Dietetic food Protein concentrate,7,,9%,7%,8%,8%,%,% ASU VO / 009/EG L-Tryptophan Dietetic food 0,0/0,,7% 7,0% 7,0% ASU L-Tyrosine Dietetic food,0,%,89%,% ASU L-Valine Dietetic food,8,0%,0%,9% ASU used in evaluation (s. chapter Page of 8

13 .. Value by perception The target standard deviation for proficiency assessment can be set at a value that corresponds to the level of performance that the coordinator would wish laboratories to be able to achieve []. For the present evaluation the target standard deviation according to.. and.. were regarded suitable. Table shows selected characteristics of participants results of the present PT in comparison to the previous year..7 z-score To assess the results of the participants the z-score is used. It indicates about which multiple of the target standard deviation (σpt the result (xi of the participant is deviating from the assigned value (Xpt []. Participants z-scores are derived from: The requirements for the analytical performance are generally considered as fulfilled if - z. The z-score valid for the PT evaluation is designated z-score (σpt, while the value of z-score (Info is for information only. The two z- scores are calculated using the different target standard deviations according to...7. Warning and action signals In accordance with the norm ISO 8 it is recommended that a result that gives rise to a z-score above,0 or below,0, shall be considered to give an action signal []. Likewise, a z-score above,0 or below,0 shall be considered to give a warning signal. A single action signal, or warning signal in two successive PT-rounds, shall be taken as evidence that an anomaly has occurred which requires investigation. For example a fault isolation or a root cause analysis through the examination of transmission error or an error in the calculation, in the trueness and precision must be performed and if necessary appropriate corrective measures should be applied []. In the figures of z-scores DLA gives the limits of warning and action signals as yellow and red lines respectively. According to ISO 8 the signals are valid only in case of a number of 0 results []. Page of 8

14 Table : Characteristics of the present PT (on dark gray in comparison to previous PTs since 0 (SD = standard deviation, CV = coefficient of variation Parameter L-Alanine L-Alanine L-Arginine L-Arginine L-Aspartic acid L-Aspartic acid L-Cystine L-Cystine L-Glutamic acid L-Glutamic acid Glycine Glycine L-Histidin L-Histidine L-Isoleucine L-Isoleucine L-Methionine L-Methionine Matrix (Powder Dietetic food Dietetic food Dietetic food Dietetic food Dietetic food Dietetic food Dietetic food Dietetic food Dietetic food Dietetic food Dietetic food Dietetic food Dietetic food Dietetic food Dietetic food Dietetic food Dietetic food Dietetic food rob. Mean rob. SD (S* rel. SD (VK S* [%] Quotient S*/σpt DLA Report 0, 0,00,7 0,77 DLA /0,70 0,0, 0,90 DLA 9/0 0,8 0,08,,9 DLA /0,7 0,8 8,0,9 DLA 9/0 0,9 0,09,0 0, DLA /0, 0,0,8 0,90 DLA 9/ DLA /0 0,87 0, 7,,89 DLA 9/0,90 0,,, DLA /0 8,9 0,0,0, DLA 9/0 0,9 0,0,07,0 DLA /0, 0,09,0, DLA 9/0 0, 0,0,9, DLA /0,0 0,09 8, 0,78 DLA 9/0 0,0 0,07,, DLA /0,9 0,7 8,9,78 DLA 9/0 0, 0,0,7 0,9 DLA /0 0,7 0,008 0,,9 DLA 9/0 Page of 8

15 Table continued: Parameter L-Leucine L-Leucine L-Lysine L-Lysine L-Proline L-Proline L-Serine L-Serine L-Phenylalanine L-Phenylalanine L-Threonine L-Threonine L-Tryptophan L-Tryptophan L-Tyrosine L-Tyrosine L-Valine L-Valine Matrix (Powder Dietetic food Dietetic food Dietetic food Dietetic food Dietetic food Dietetic food Dietetic food Dietetic food Dietetic food Dietetic food Dietetic food Dietetic food Dietetic food Dietetic food Dietetic food Dietetic food Dietetic food Dietetic food rob. Mean rob. SD (S* rel. SD (VK S* [%] Quotient S*/σpt DLA Report,0 0,088,80 0,9 DLA /0, 0,8 7,9, DLA 9/0 0,87 0,09,7,7 DLA /0,7 0,8,0,8 DLA 9/0 0,08 0,00,9,07 DLA /0, 0,,7,88 DLA 9/0 0,7 0,09, 0,7 DLA /0, 0,, 0,8 DLA 9/0 0,8 0,07,,77 DLA /0, 0,0,9,9 DLA 9/0 0, 0,00,79 0,8 DLA /0,0 0,09,7, DLA 9/ DLA /0 0, 0,090 0,,9 DLA 9/0 0, 0,00 7,8,7 DLA /0, 0, 0,, DLA 9/0 0,98 0,0,0,9 DLA /0,0 0,97 9,, DLA 9/0 Page of 8

16 .8 z'-score The z'-score can be used for the valuation of the results of the participants, in cases the standard uncertainty has to be considered (s..8. The z'-score represents the relation of the deviation of the result (x of the participant from the respective consensus value (X to the square root of quadrat sum of the target standard deviation ( σ and the standard uncertainty (Ux pt []. The calculation is performed by: If carried out an evaluation of the results by means of z 'score, we have defined below the expression in the denominator as a target standard deviation σ pt '. The requirements for the analytical performance are generally considered as fulfilled if - z'. For warning and action signals see Reproducibility coefficient of variation (CV R The coefficient of variation (CV R of the reproducibility (= relative reproducibility standard deviation is calculated from the standard deviation and the mean as follows [, ]: CV R = S R * 00 In contrast to the standard deviation as a measure of the absolute variability the CV K gives the relative variability within a data region. While a low CV R, e.g. < -0% can be taken as evidence for a homogeneous set of results, a CV R of more than 0% indicates a "strong inhomogeneity of statistical mass", so that the suitability for certain applications such as the assessment of exceeded maximum values or the performance evaluation of the participants possibly can not be done []. X Page of 8

17 .0 Quotient S*/σ pt Following the HorRat-value the results of a proficiency-test (PT can be considered convincing, if the quotient of robust standard deviation S* and target standard deviation σ pt does not exceed the value of. A value > means an insufficient precision, i.e. the analytical method is too variable, or the variation between the test participants is higher than estimated. Thus the comparability of the results is not given [].. Standard uncertainty The consensus value has a standard uncertainty U(X pt that depends on the analytical method, differences between the analytical methods used, the test material, the number of participant laboratories (P and perhaps on other factors. The standard uncertainty of the assigned value (U(Xpt for this PT is calculated as follows []: If U(Xpt 0, σpt the standard uncertainty of the consensus value needs not to be included in the interpretation of the results of the PT []. A clear exceeded the value of 0, is an indication that the target standard deviation was possibly set too low for the standard uncertainty of the assigned value. The quotient U(X pt/σ pt is reported in the characteristics of the test. Page 7 of 8

18 . Results Comments to the distribution of the results: The kernel density plots showed for all parameters nearly a normal distribution of results (figures see documentation.. Partly slight shoulders and separate smaller peaks can be seen, which are due to individual values and outliers. In the case of lysine and valine a distribution of results with two peaks can be seen. However, the information provided by the participants on the methods gave no obvious indications of such an array of results. When using the robust standard deviation as an estimator h, the distributions are converted into single peak distributions, so that an statistical evaluation has been carried out. Comments to the statistic data: For cysteine there were < 7 results, therefore no statistical evaluation could be done. The target standard deviation was calculated for all other elements according to the model of Horwitz or according to the data of a precision experiment (ASU method. The evaluation according to Horwitz was preferably used as long as the quotients S*/σpt were in the range of,0. In all other cases, the standard deviation calculated from ASU precision data was used. For proline and threonine the target standard deviation was calculated according to ASU, because the Horwitz evaluation was considered too strict for these results. For all parameters the distribution of results showed a normal variability. The quotients S*/σpt were all below,0 in the range of 0,78 to,9 (see table. The robust standard deviation as well as the repeatability and reproducibility standard deviations were in the range of established values for the applied methods (see... The comparability of results is given. The quotient U(Xpt/σpt was increased > 0, for all parameters (0, bis 0,8, from which quotients were in a slightly increased range of < 0, and 8 quotients > 0,. 70% to 00% of results were in the target range. The robust means of the participant results, with the exception of histidine, ranged from 9% to % of the amino acid content according to the manufacturer's specification (see Table. Page 8 of 8

19 All following tables are anonymized. With the delivering of the evaluation-report the participants are informed about their individual evaluation-number. In the first table the characteristics are listed: Statistic Data Number of results Number of outliers Mean Median Robust mean(x pt Robust standard deviation (S x Number with m replicate measurements Repeatability standard deviation (S r Coefficient of Variation (CV r in % Reproducibility standard deviation (S R Coefficient of Variation (CV R in % Target range: Target standard deviation σ pt or σ pt ' Target standard deviation for information lower limit of target range (X pt σ pt or (X pt σ pt ' * upper limit of target range (X pt + σ pt or (X pt + σ pt ' * Variation coefficient V K in % Quotient S*/σ pt or S*/σ pt ' Standard uncertainty U(X pt Quotient U(X pt /σ pt or U(X pt /σ pt ' Number of results in the target range Percent in the target range * Target range is calculated with z-score or z'-score In the second table the individual results of the participating laboratories are listed: Auswertenummer Parameter Evaluation [Einheit / Unit] number Abweichung Deviation z-score σpt z-score (Info Hinweis Remark Page 9 of 8

20 . L-Alanin/L-Alanine in g/00g Vergleichsuntersuchung / Proficiency Test Statistic Data Number of results 0 Number of outliers 0 Mean,70 Median,9 Robust Mean (X,70 Robust standard deviation (S* 0,0 Number with replicates 0 Repeatability SD (S r 0,0 Repeatability (CV r,9% Reproducibility SD (S R 0,00 Reproducibility (CV R,% Target range: Target standard deviation σpt 0,07 Target standard deviation (for 0,08 Information lower limit of target range,7 upper limit of target range,8 Quotient S*/σpt Standard uncertainty U(Xpt Quotient U(Xpt/σpt 0,90 0,0 0, Results in the target range 0 Percent in the target range 00% Ergebnisse / Results,,,0,8,,,0 0,8 0, 0, 0,0 7 8 Auswertenummer / evaluation number 9 0 L-Alanin(e Obergrenze upper limit robuster Mittelwert robust mean Untergrenze lower limit Abb. / Fig. : Ergebnisse L-Alanin / Results L-Alanine Page 0 of 8

21 Ergebnisse der Teilnehmer: Results of Participants: Auswertenummer Evaluation number L-Alanin / L-Alanine Abweichung Deviation, -0,0-0, -0,,77 0,07, 0,9,8 0,,0,,9-0,00-0, -0,, -0,0-0, -0,,70 0,00 0, 0,0 7,7 0,0 0, 0, 8, -0,0 -, -0,8 9,9-0,009-0, -0, 0, -0,07-0, -0, z-score z-score Hinweis (σpt (Info Remark,0 z-scores,0,0,0,0 0,0 -,0 -,0 -,0 -,0 -, Auswertenummer / evaluation number Abb. / Fig. : Z-Scores L-Alanin / L-Alanine Page of 8

22 . L-Arginin/L-Arginine in g/00g Vergleichsuntersuchung / Proficiency Test Statistic Data Number of results 0 Number of outliers 0 Mean,7 Median,7 Robust Mean (X,7 Robust standard deviation (S* 0,8 Number with replicates 9 Repeatability SD (S r 0,09 Repeatability (CV r,8% Reproducibility SD (S R 0,0 Reproducibility (CV R 7,% Target range: Target standard deviation σpt 0,8 Target standard deviation (for 0,097 Information lower limit of target range, upper limit of target range,09 Quotient S*/σpt Standard uncertainty U(Xpt Quotient U(Xpt/σpt,9 0,080 0,7 Results in the target range 9 Percent in the target range 90% Ergebnisse / Results,,0,,0,,0 0, 0,0 7 8 Auswertenummer / evaluation number 9 0 L-Arginin(e Obergrenze upper limit robuster Mittelwert robust mean Untergrenze lower limit Abb. / Fig. : Ergebnisse L-Arginin / Results L-Arginine Page of 8

23 Ergebnisse der Teilnehmer: Results of Participants: Auswertenummer Evaluation number L-Arginin / L-Arginine Abweichung Deviation,7-0,0-0, -0,,0 0,9,,,88 0, 0,9,7,79 0,0 0, 0,7,0-0, -0,7 -,,87 0, 0,8, 7,7-0,0-0, -0, 8,8-0, -, -, 9,8 0,09 0,,0 0, -0,7 -,0 -,0 z-score z-score Hinweis (σpt (Info Remark,0 z-scores,0,0,0,0 0,0 -,0 -,0 -,0 -,0 -, Auswertenummer / evaluation number Abb. / Fig. : Z-Scores L-Arginin / L-Arginine Page of 8

24 . L-Asparaginsäure/L-Aspartic acid in g/00g Vergleichsuntersuchung / Proficiency Test Statistic Data Number of results 9 Number of outliers Mean, Median, Robust Mean (X, Robust standard deviation (S* 0,0 Number with replicates 9 Repeatability SD (S r 0,088 Repeatability (CV r,98% Reproducibility SD (S R 0,0 Reproducibility (CV R 9,% Target range: Target standard deviation σpt 0, Target standard deviation (for 0, Information lower limit of target range, upper limit of target range,8 Quotient S*/σpt Standard uncertainty U(Xpt Quotient U(Xpt/σpt 0,90 0,0 0,7 Results in the target range 8 Percent in the target range 89% Ergebnisse / Results,0,0,0,0,0,0 0,0 7 8 Auswertenummer / evaluation number 9 0 L-Asparagin- säure/l- Aspartic acid Obergrenze upper limit robuster Mittelw ert robust mean Untergrenze low er limit Abb. / Fig. : Ergebnisse L-Assparginsäure / Results L-Aspartic acid Page of 8

25 Ergebnisse der Teilnehmer: Results of Participants: Auswertenummer Evaluation number L-Asparaginsäure / L-Aspartic acid Abweichung Deviation z-score z-score Hinweis Remark,0-0,07-0, -0,,8 0,8,0 0,9,9 0,0 0, 0,,8-0,07-0, -0,,9-0,7 -, -,9 Ausreisser / Outlier, -0,07-0, 0,0 7, 0,79 0,8 0, 8,7-0,077-0, -0, 9,9 0,00 0, 0, 0, -0,9 (σpt (Info Ausreisser ausgeschlossen* / Outlier excluded* * Einfluss auf robuste Statistik / * influence on robust statistics,0 z-scores,0,0,0,0 0,0 -,0 -,0 -,0 -,0 -, Auswertenummer / evaluation number Abb. / Fig. : Z-Scores L-Asparaginsäure / L-Aspartic acid Page of 8

26 . L-Cystein/L-Cysteine in g/00g Vergleichsuntersuchung / Proficiency Test Statistic Data Number of results Number of outliers 0 Mean 0,8 Median 0,8 Robust Mean (X 0,8 Robust standard deviation (S* 0,07 Number with replicates Repeatability SD (S r Repeatability (CV r Reproducibility SD (S R Reproducibility (CV R Target range: Target standard deviation σpt Target standard deviation (for Information lower limit of target range upper limit of target range Quotient S*/σpt Standard uncertainty U(Xpt Quotient U(Xpt/σpt Results in the target range Percent in the target range Ergebnisse / Results 0,7 0, 0, 0, L-Cystein(e 0, 0, 0, robuster Mittelwert robust mean 0,0 7 8 Auswertenummer / evaluation number 9 0 Abb. / Fig. 7: Ergebnisse L-Cystein / Results L-Cysteine Page of 8

27 Ergebnisse der Teilnehmer: Results of Participants: Auswertenummer Evaluation number L-Cystein(e Abweichung Deviation 7 8 0,0 0,08 9 0, -0,08 0 z-score z-score Hinweis (σpt (Info Remark Page 7 of 8

28 . L-Cystin/L-Cystine in g/00g Vergleichsuntersuchung / Proficiency Test Statistic Data Number of results 8 Number of outliers 0 Mean 0,87 Median 0,7 Robust Mean (X 0,87 Robust standard deviation (S* 0, Number with replicates 7 Repeatability SD (S r 0,09 Repeatability (CV r,8% Reproducibility SD (S R 0, Reproducibility (CV R 9,% Target range: Target standard deviation σpt 0,070 Target standard deviation (for 0,07 Information lower limit of target range 0, upper limit of target range 0, Quotient S*/σpt Standard uncertainty U(Xpt Quotient U(Xpt/σpt,89 0,090 0,8 Results in the target range Percent in the target range 7% Ergebnisse / Results 0,9 0,8 0,7 0, 0, 0, 0, 0, 0, 0,0 7 8 Auswertenummer / evaluation number 9 0 L-Cystin(e Obergrenze upper limit robuster Mittelwert robust mean Untergrenze lower limit Abb. / Fig. 8: Ergebnisse L-Cystin / Results L-Cystine Page 8 of 8

29 Ergebnisse der Teilnehmer: Results of Participants: Auswertenummer Evaluation number L-Cystin(e Abweichung Deviation 0,0-0,077 -, -, 0,70 0,, 0, 0,0 0,0 0,, 0,0-0,07-0, -, 0,0-0,07-0, -, 0,8-0,00 0,0-0, ,90 0,0,,7 0 0,0-0,7 -, -0, z-score z-score Hinweis (σpt (Info Remark,0 z-scores,0,0,0,0 0,0 -,0 -,0 -,0 -,0 -,0 0 9 Auswertenummer / evaluation number Abb. / Fig. 9: Z-Scores L-Cystin / L-Cystine Page 9 of 8

30 . L-Glutaminsäure/L-Glutamic acid in g/00g Vergleichsuntersuchung / Proficiency Test Statistic Data Number of results 0 Number of outliers 0 Mean 8,9 Median 8, Robust Mean (X 8,9 Robust standard deviation (S* 0,0 Number with replicates 9 Repeatability SD (S r 0,0 Repeatability (CV r,70% Reproducibility SD (S R 0,7 Reproducibility (CV R,7% Target range: Target standard deviation σpt 0,0 Target standard deviation (for 0, Information lower limit of target range 7,8 upper limit of target range 9, Quotient S*/σpt Standard uncertainty U(Xpt Quotient U(Xpt/σpt, 0,98 0,9 Results in the target range 0 Percent in the target range 00% Ergebnisse / Results Auswertenummer / evaluation number 9 0 L-Glutaminsäure/L-Glutamic acid Obergrenze upper limit robuster Mittelw ert robust mean Untergrenze low er limit Abb. / Fig. 0: Ergebnisse L-Glutaminsäure/ Results L-Glutamic acid Page 0 of 8

31 Ergebnisse der Teilnehmer: Results of Participants: Auswertenummer Evaluation number L-Glutaminsäure/ L-Glutamic acid Abweichung Deviation 8,09-0,0-0, -0,8 9,0 0,7,8,0 8,7 0,7 0,9, 7,98-0, -0,8 -, 7,9-0,0 -, -, 8,8-0, -0, -0, 7 8,77 0,7,,0 8 8, 0, 0,8, 9 8,0-0, -0, -,0 0 7,8-0, -, -,8 z-score z-score Hinweis (σpt (Info Remark,0 z-scores,0,0,0,0 0,0 -,0 -,0 -,0 -,0 -, Auswertenummer / evaluation number 7 Abb. / Fig. : Z-Scores L-Glutaminsäure / L-Glutamic acid Page of 8

32 .7 Glycin/Glycine in g/00g Vergleichsuntersuchung / Proficiency Test Statistic Data Number of results 0 Number of outliers 0 Mean, Median,7 Robust Mean (X, Robust standard deviation (S* 0,09 Number with replicates 9 Repeatability SD (S r 0,00 Repeatability (CV r,8% Reproducibility SD (S R 0,08 Reproducibility (CV R,7% Target range: Target standard deviation σpt 0,07 Target standard deviation (for 0,0 Information lower limit of target range, upper limit of target range, Quotient S*/σpt Standard uncertainty U(Xpt Quotient U(Xpt/σpt, 0,09 0, Results in the target range 7 Percent in the target range 70% Ergebnisse / Results,0,8,,,0 0,8 0, 0, 0,0 7 8 Auswertenummer / evaluation number 9 0 Glycin(e Obergrenze upper limit robuster Mittelwert robust mean Untergrenze lower limit Abb. / Fig. : Ergebnisse Glycin/ Results Glycine Page of 8

33 Ergebnisse der Teilnehmer: Results of Participants: Auswertenummer Evaluation number Glycin(e Abweichung Deviation,9-0,07-0,8-0,, 0,,,,0 0,0, 0,,7 0,0 0, 0,,7 0,0 0, 0,, 0,0 0, 0, 7,7 0,0 0, 0, 8,0-0,7 -, -, 9, 0,00 0, 0, 0, -0,0 -, -, z-score z-score Hinweis (σpt (Info Remark,0 z-scores,0,0,0,0 0,0 -,0 -,0 -,0 -,0 -, Auswertenummer / evaluation number Abb. / Fig. : Z-Scores Glycin / Glycine Page of 8

34 .8 L-Histidin/L-Histidine in g/00g Vergleichsuntersuchung / Proficiency Test Statistic Data Number of results 0 Number of outliers 0 Mean,0 Median,07 Robust Mean (X,0 Robust standard deviation (S* 0,09 Number with replicates 9 Repeatability SD (S r 0,00 Repeatability (CV r,0% Reproducibility SD (S R 0,078 Reproducibility (CV R,9% Target range: Target standard deviation σpt 0,8 Target standard deviation (for 0,0 Information lower limit of target range 0,8 upper limit of target range, Quotient S*/σpt Standard uncertainty U(Xpt Quotient U(Xpt/σpt 0,78 0,0 0, Results in the target range 0 Percent in the target range 00% Ergebnisse / Results,,,0 0,8 0, 0, 0, 0,0 7 8 Auswertenummer / evaluation number 9 0 L-Histidin(e Obergrenze upper limit robuster Mittelwert robust mean Untergrenze lower limit Abb. / Fig. : Ergebnisse L-Histidin/ Results L-Histidine Page of 8

35 Ergebnisse der Teilnehmer: Results of Participants: Auswertenummer Evaluation number L-Histidin / L-Histidine Abweichung Deviation,0-0,087-0,7 -,0, 0,,0,, 0,,0,8,0-0,07-0, -,,9 0,09 0,8,,08-0,07-0, -0, 7,0-0,00-0, -0,9 8,0-0,07-0, -, 9, 0,0 0, 0, 0,0-0,08-0, -, z-score z-score Hinweis (σpt (Info Remark,0 z-scores,0,0,0,0 0,0 -,0 -,0 -,0 -,0 -, Auswertenummer / evaluation number Abb. / Fig. : Z-Scores L-Histidin / L-Histidine Page of 8

36 .9 L-Isoleucin/L-Isoleucine in g/00g Vergleichsuntersuchung / Proficiency Test Statistic Data Number of results 0 Number of outliers Mean,9 Median,97 Robust Mean (X,9 Robust standard deviation (S* 0,7 Number with replicates 9 Repeatability SD (S r 0,0 Repeatability (CV r,87% Reproducibility SD (S R 0, Reproducibility (CV R,7% Target range: Target standard deviation σpt 0,097 Target standard deviation (for 0,070 Information lower limit of target range,7 upper limit of target range, Quotient S*/σpt Standard uncertainty U(Xpt Quotient U(Xpt/σpt,78 0,08 0,70 Results in the target range 9 Percent in the target range 90% Ergebnisse / Results,,,0,8,,,0 0,8 0, 0, 0,0 7 8 Auswertenummer / evaluation number 9 0 L-Isoleucin(e Obergrenze upper limit robuster Mittelw ert robust mean Untergrenze low er limit Abb. / Fig. : Ergebnisse L-Isoleucin/ Results L-Isoleucine Page of 8

37 Ergebnisse der Teilnehmer: Results of Participants: Auswertenummer Evaluation number L-Isoleucin / L-Isoleucine Abweichung Deviation z-score z-score Hinweis (σpt (Info Remark,79-0,0 -, -,,08 0,99,,0,9 0,099 0, 0,,97 0,099 0, 0,, 0,99,7,,09 0,99,, 7,0 0,07,, 8,9-0,00-0, -0, 9,7-0,9 -,0 -,7 0, -0,80 -,9-8, Ausreisser/Outlier,0,0,0,0,0 0,0 -,0 -,0 -,0 -,0 -,0 -,0 0 9 z-scores 7 8 Auswertenummer / evaluation number Abb. / Fig. 7: Z-Scores L-Isoleucin / L-Isoleucine Page 7 of 8

38 .0 L-Leucin/L-Leucine in g/00g Vergleichsuntersuchung / Proficiency Test Statistic Data Number of results 0 Number of outliers 0 Mean, Median, Robust Mean (X, Robust standard deviation (S* 0,8 Number with replicates 9 Repeatability SD (S r 0,09 Repeatability (CV r,8% Reproducibility SD (S R 0, Reproducibility (CV R,7% Target range: Target standard deviation σpt 0,8 Target standard deviation (for 0, Information lower limit of target range,08 upper limit of target range,8 Quotient S*/σpt Standard uncertainty U(Xpt Quotient U(Xpt/σpt, 0,098 0, Results in the target range 9 Percent in the target range 90% Ergebnisse / Results,0,,0,,0,,0,,0 0, 0,0 7 8 Auswertenummer / evaluation number 9 0 L-Leucin(e Obergrenze upper limit robuster Mittelwert robust mean Untergrenze lower limit Abb. / Fig. 8: Ergebnisse L-Leucin/ Results L-Leucine Page 8 of 8

39 Ergebnisse der Teilnehmer: Results of Participants: Auswertenummer Evaluation number L-Leucin/ L-Leucine Abweichung Deviation,0-0,0-0,8 -,,7 0,80,,, 0,780,0,, -0,00-0, -0,9,8 0,80,9,,0 0,080 0, 0, 7, -0,08-0, -0, 8,9-0,00-0, -0, 9, -0,0-0,8 -, 0,0-0,00 -, -,7 z-score z-score Hinweis (σpt (Info Remark,0 z-scores,0,0,0,0 0,0 -,0 -,0 -,0 -,0 -, Auswertenummer / evaluation number Abb. / Fig. 9: Z-Scores L-Leucin / L-Leucine Page 9 of 8

40 . L-Lysin/L-Lysine in g/00g Vergleichsuntersuchung / Proficiency Test Statistic Data Number of results 0 Number of outliers 0 Mean,7 Median,7 Robust Mean (X,7 Robust standard deviation (S* 0,8 Number with replicates 9 Repeatability SD (S r 0,0 Repeatability (CV r,7% Reproducibility SD (S R 0, Reproducibility (CV R,79% Target range: Target standard deviation σpt 0,09 Target standard deviation (for 0,9 Information lower limit of target range, upper limit of target range,89 Quotient S*/σpt Standard uncertainty U(Xpt Quotient U(Xpt/σpt,8 0,0 0,7 Results in the target range 9 Percent in the target range 90% Ergebnisse / Results,0,,0,,0,,0 0, 0,0 7 8 Auswertenummer / evaluation number 9 0 L-Lysin(e Obergrenze upper limit robuster Mittelwert robust mean Untergrenze lower limit Abb. / Fig. 0: Ergebnisse L-Lysin/ Results L-Lysine Page 0 of 8

41 Ergebnisse der Teilnehmer: Results of Participants: Auswertenummer Evaluation number L-Lysin / L-Lysine Abweichung Deviation,9-0,70 -, -0,,8 0,0, 0,,8 0,00, 0,,89 0,80,0 0,8,7 0,00 0, 0,,8 0,0, 0, 7,70-0,00 0,0 0,0 8, -0,70 -,7-0,7 9, -0,0990 -, -0, 0, -0,90 -,7 -,0 z-score z-score Hinweis (σpt (Info Remark,0 z-scores,0,0,0,0 0,0 -,0 -,0 -,0 -,0 -, Auswertenummer / evaluation number Abb. / Fig. : Z-Scores L-Lysin / L-Lysine Page of 8

42 . L-Methionin/L-Methionine in g/00g Vergleichsuntersuchung / Proficiency Test Statistic Data Number of results 0 Number of outliers 0 Mean 0, Median 0,70 Robust Mean (X 0,7 Robust standard deviation (S* 0,008 Number with replicates 9 Repeatability SD (S r 0,009 Repeatability (CV r,78% Reproducibility SD (S R 0,08 Reproducibility (CV R,% Target range: Target standard deviation σpt 0,08 Target standard deviation (for 0,09 Information lower limit of target range 0,0 upper limit of target range 0, Quotient S*/σpt Standard uncertainty U(Xpt Quotient U(Xpt/σpt,9 0,00 0, Results in the target range 8 Percent in the target range 80% Ergebnisse / Results 0,8 0,7 0, 0, 0, 0, 0, 0, 0,0 7 8 Auswertenummer / evaluation number 9 0 L-Methionin(e Obergrenze upper limit robuster Mittelw ert robust mean Untergrenze low er limit Abb. / Fig. : Ergebnisse L-Methionin/ Results L-Methionine Page of 8

43 Ergebnisse der Teilnehmer: Results of Participants: Auswertenummer Evaluation number L-Methionin(e Abweichung Deviation 0,90 0,080 0, 0,7 0,00 0,080 0,7, 0,0 0,0780,0, 0,80 0,0080 0, 0, 0,0-0,00-0, -0, 0,8 0,070,0, 7 0, -0,078 -, -,9 8 0,0-0,0 -, -, 9 0,9-0,00-0, -0, 0 0,8-0,00 -, -,8 z-score z-score Hinweis (σpt (Info Remark,0 z-scores,0,0,0,0 0,0 -,0 -,0 -,0 -,0 -, Auswertenummer / evaluation number Abb. / Fig. : Z-Scores L-Methionin / L-Methionine Page of 8

44 . L-Phenylalanin/L-Phenylalanine in g/00g Vergleichsuntersuchung / Proficiency Test Statistic Data Number of results 0 Number of outliers 0 Mean, Median, Robust Mean (X, Robust standard deviation (S* 0, Number with replicates Repeatability SD (S r Repeatability (CV r Reproducibility SD (S R Reproducibility (CV R 9 0,0,% 0,78 8,8% Target range: Target standard deviation σpt 0,07 lower limit of target range,99 upper limit of target range,0 Quotient S*/σpt Standard uncertainty U(Xpt Quotient U(Xpt/σpt,88 0,09 0,7 Results in the target range 7 Percent in the target range 70% Ergebnisse / Results,0,,0,,0 0, 0,0 7 8 Auswertenummer / evaluation number 9 0 L-Phenylalanin(e Obergrenze upper limit robuster Mittelw ert robust mean Untergrenze low er limit Abb. / Fig. : Ergebnisse L-Phenylalanin/ Results L-Phenylalanine Page of 8

45 Ergebnisse der Teilnehmer: Results of Participants: Auswertenummer Evaluation number L-Phenylalanin(e Abweichung Deviation z-score (σpt,0-0,7 -,, 0,,, -0,07-0,,09-0,07-0,7,9 0,,, 0,0 0,9 7, 0,0099 0, 8, 0,0 0, 9,08-0,07-0,8 0,8-0,87 -,7 Hinweis Remark,0,0,0,0,0,0 0,0 -,0 -,0 -,0 -,0 -,0 0 z-scores Auswertenummer / evaluation number Abb. / Fig. : Z-Scores L-Phenylalanin / L-Phenylalanine Page of 8

46 . L-Prolin/L-Proline in g/00g Vergleichsuntersuchung / Proficiency Test Statistic Data Number of results 0 Number of outliers 0 Mean,0 Median, Robust Mean (X, Robust standard deviation (S* 0, Number with replicates 9 Repeatability SD (S r 0,099 Repeatability (CV r,8% Reproducibility SD (S R 0,9 Reproducibility (CV R 7,9% Target range: Target standard deviation σpt 0,90 Target standard deviation (for 0,087 Information lower limit of target range,0 upper limit of target range,80 Quotient S*/σpt Standard uncertainty U(Xpt Quotient U(Xpt/σpt 0,8 0,07 0, Results in the target range 9 Percent in the target range 90% Ergebnisse / Results,,0,,0,,0 0, 0,0 7 8 Auswertenummer / evaluation number 9 0 L-Prolin(e Obergrenze upper limit robuster Mittelwert robust mean Untergrenze lower limit Abb. / Fig. : Ergebnisse L-Prolin/ Results L-Proline Page of 8

47 Ergebnisse der Teilnehmer: Results of Participants: Auswertenummer Evaluation number L-Prolin / L-Proline Abweichung Deviation, -0,0080 0,0-0,, 0,0,,, -0,780-0,9 -,,8 0,00 0, 0,7,98-0,80 -, -,, 0,00 0,, 7, 0,0 0, 0, 8, -0,0780-0, -0,9 9, 0,00 0,7,7 0,8-0,00-0, -0, z-score z-score Hinweis (σpt (Info Remark,0 z-scores,0,0,0,0 0,0 -,0 -,0 -,0 -,0 -, Auswertenummer / evaluation number 9 Abb. / Fig. 7: Z-Scores L-Prolin / L-Proline Page 7 of 8

48 . L-Serin/L-Serine in g/00g Vergleichsuntersuchung / Proficiency Test Statistic Data Number of results 0 Number of outliers 0 Mean, Median, Robust Mean (X, Robust standard deviation (S* 0,0 Number with replicates 9 Repeatability SD (S r 0,0 Repeatability (CV r,% Reproducibility SD (S R 0, Reproducibility (CV R,% Target range: Target standard deviation σpt 0,079 Target standard deviation (for 0,099 Information lower limit of target range,07 upper limit of target range,9 Quotient S*/σpt Standard uncertainty U(Xpt Quotient U(Xpt/σpt,9 0,0 0, Results in the target range 8 Percent in the target range 80% Ergebnisse / Results,0,7,,,8,, 0,9 0, 0, 0,0 7 8 Auswertenummer / evaluation number 9 0 L-Serin(e Obergrenze upper limit robuster Mittelwert robust mean Untergrenze lower limit Abb. / Fig. 8: Ergebnisse L-Serin/ Results L-Serine Page 8 of 8

49 Ergebnisse der Teilnehmer: Results of Participants: Auswertenummer Evaluation number L-Serin / L-Serine Abweichung Deviation, -0,00-0, -0,, 0,79,,8, 0,09 0, 0,, 0,99,,0, -0,00-0, -0,, -0,090 -, -0,9 7,7-0,0-0,8-0,7 8,0-0,00-0, -0, 9, 0,00 0, 0, 0,0-0, -,7 -, z-score z-score Hinweis (σpt (Info Remark,0 z-scores,0,0,0,0 0,0 -,0 -,0 -,0 -,0 -, Auswertenummer / evaluation number Abb. / Fig. 9: Z-Scores L-Serin/ L-Serine Page 9 of 8

50 . L-Threonin/L-Threonine in g/00g Vergleichsuntersuchung / Proficiency Test Statistic Data Number of results 0 Number of outliers 0 Mean,9 Median, Robust Mean (X,0 Robust standard deviation (S* 0,09 Number with replicates 9 Repeatability SD (S r 0,0 Repeatability (CV r,% Reproducibility SD (S R 0,0 Reproducibility (CV R,7% Target range: Target standard deviation σpt 0,0900 Target standard deviation (for 0,09 Information lower limit of target range, upper limit of target range,78 Quotient S*/σpt Standard uncertainty U(Xpt Quotient U(Xpt/σpt,0 0,0 0,0 Results in the target range 9 Percent in the target range 90% Ergebnisse / Results,,,0,8,,,0 0,8 0, 0, 0,0 7 8 Auswertenummer / evaluation number 9 0 L-Threonin / L-Threonine Obergrenze upper limit robuster Mittelwert robust mean Abb. / Fig. 0: Ergebnisse L-Threonin/ Results L-Threonine Page 0 of 8

51 Ergebnisse der Teilnehmer: Results of Participants: Auswertenummer Evaluation number L-Threonin / L-Threonine Abweichung Deviation z-score z-score Hinweis (σpt (Info,8-0,07-0, -0,,7 0,,,, 0,0 0, 0,,9 0,09,0,, 0,0 0, 0,,0 0,00 0,0 0,0 7, 0,0 0, 0, 8,8-0,7 -, -,0 9,8-0,07-0, -0, 0,8-0,9 -, -,7 Remark,0 z-scores,0,0,0,0 0,0 -,0 -,0 -,0 -,0 -, Auswertenummer / evaluation number Abb. / Fig. : Z-Scores L-Threonin / L-Threonine Page of 8

52 .7 L-Tryptophan in g/00g Vergleichsuntersuchung / Proficiency Test Statistic Data Number of results 7 Number of outliers 0 Mean 0,70 Median 0,70 Robust Mean (X 0, Robust standard deviation (S* 0,090 Number with replicates Repeatability SD (S r 0,0 Repeatability (CV r,% Reproducibility SD (S R 0,07 Reproducibility (CV R,% Target range: Target standard deviation σpt 0,09 Target standard deviation (for 0,0 Information lower limit of target range 0,8 upper limit of target range 0, Quotient S*/σpt Standard uncertainty U(Xpt Quotient U(Xpt/σpt,9 0,079 0,7 Results in the target range Percent in the target range 8% Ergebnisse / Results 0,8 0,7 0, 0, 0, 0, 0, 0, 0,0 7 8 Auswertenummer / evaluation number 9 0 L-Tryptophan Obergrenze upper limit robuster Mittelw ert robust mean Untergrenze low er limit Abb. / Fig. : Ergebnisse L-Tryptophan / Results L-Tryptophan Page of 8