Results of Proficiency Test Fuel/Bio-ethanol December 2015

Transcription

1 Results of Proficiency Test Fuel/Bio-ethanol December 215 Organised by: Authors: Correctors: Report: Institute for Interlaboratory Studies (iis) Spijkenisse, the Netherlands ing. R.J. Starink dr. R.G. Visser & ing. L. Sweere iis15c14 February 216

2 Institute for Interlaboratory Studies Spijkenisse, February 216 CONTENTS 1 INTRODUCTION SET UP ACCREDITATION PROTOCOL CONFIDENTIALITY STATEMENT SAMPLES STABILITY OF THE SAMPLES ANALYSES RESULTS STATISTICS GRAPHICS Z-SCORES EVALUATION EVALUATION PER TEST PERFORMANCE EVALUATION FOR THE GROUP OF LABORATORIES COMPARISON OF THE PROFICIENCY TEST OF DECEMBER 215 WITH PREVIOUS PTS Appendices: 1. Data and statistical results Number of participants in alphabetical country order Abbreviations and literature Page 2 of 49 Fuel/Bio-Ethanol iis15c14

3 Spijkenisse, February 216 Institute for Interlaboratory Studies 1 INTRODUCTION Since 1995, a proficiency test for Fuel/Bio-Ethanol was organised every year by the Institute for Interlaboratory Studies. During the annual proficiency testing program 215/216, it was decided to continue the round robin for the analysis of Fuel/Bio-ethanol in agreement with EN15376:14 and ASTM D486:15. In this interlaboratory study for Fuel/Bio-ethanol, 71 laboratories in 32 different countries have participated. See appendix 2 for the number of participants per country. In this report, the results of the Fuel/Bio-Ethanol 215 proficiency test are presented and discussed. This report is also electronically available through the iis internet site 2 SET-UP The Institute for Interlaboratory Studies (iis) in Spijkenisse, the Netherlands, was the organiser of this proficiency test. Sample analyses for fit-for-use and homogeneity testing were subcontracted to an accredited laboratory. It was decided to send 2 samples of Ethanol 1 * 1 L bottle of Fuel/Bio-ethanol labelled #1523 and 1*.25 L bottle of Fuel/Bio-ethanol labelled #15231, especially for Gas Chromatography. Participants were requested to report the analytical results using the indicated units and to report rounded and unrounded results. The unrounded results were preferably used for statistical evaluation. 2.1 ACCREDITATION The Institute for Interlaboratory Studies in Spijkenisse, the Netherlands, is accredited in agreement with ISO/IEC 1743:21 (R7), since January 2, by the Dutch Accreditation Council (Raad voor Accreditatie). This PT falls under the accredited scope. This ensures strict adherence to protocols for sample preparation and statistical evaluation and 1% confidentially of participant s data. Feedback from the participants on the reported data is encouraged and customer s satisfaction is measured on regular basis by sending out questionnaires. 2.2 PROTOCOL The protocol followed in the organisation was the one as described for proficiency testing in the report iis Interlaboratory Studies: Protocol for the Organisation, Statistics and Evaluation of April 214 (iis-protocol, version 3.3). This protocol is electronically available through the iis internet site from the FAQ page. 2.3 CONFIDENTIALITY STATEMENT All data presented in this report must be regarded as confidential and for use by the participating companies only. Disclosure of the information in this report is only allowed by means of the entire report. Use of the contents of this report for third parties is only allowed by written permission of the Institute for Interlaboratory Studies. Disclosure of the identity of one or more of the participating companies will be done only after receipt of a written agreement of the companies involved. Fuel/Bio-Ethanol iis15c14 page 3 of 49

4 Institute for Interlaboratory Studies Spijkenisse, February SAMPLES The necessary bulk material for samples #1523 and #15231 was obtained from a local trader. The bulk material was split in two for preparation of the samples. The first batch, approximately 9 litres, was spiked with mg Sodium Chloride in a precleaned drum. After homogenisation, 88 amber glass bottles of 1L were filled and labelled #1523. The homogeneity of the subsamples #1523 was checked by determination of Density in accordance with ASTM D452, Chloride in accordance with In house test method and Water in accordance with ASTM E23 on 8 stratified randomly selected samples. Density at 2ºC in kg/l Chloride in mg/kg Water in %M/M Sample # Sample # Sample # Sample # Sample # Sample # Sample # Sample # Table 1: Homogeneity tests results of subsamples #1523 From the test results of table 1, the repeatabilities were calculated and compared with.3 times the corresponding target reproducibility in agreement with the procedure of ISO 13528, Annex B2 in the next table: Density at 2ºC in kg/l Chloride in mg/kg Water in %M/M r (Observed) reference method ISO12185:96 EN15492:12 EN15489:7.3 * R (ref. Method) Table 2: Repeatability of subsamples #1523 The second batch, approximately 2 litres, was homogenised in a precleaned drum. After homogenisation, 8 amber glass bottles of.25l were filled and labelled # The homogeneity of the subsamples #15231 was checked by determination of Methanol in accordance with EN15721, proc. A on 8 stratified randomly selected samples. Methanol in %M/M Sample # Sample # Sample # Sample # Sample # Sample # Sample # Sample # Table 3: Homogeneity tests results of subsamples #15231 Page 4 of 49 Fuel/Bio-Ethanol iis15c14

5 Spijkenisse, February 216 Institute for Interlaboratory Studies From the test results of table 3, the repeatability was calculated and compared with.3 times the corresponding target reproducibility in agreement with the procedure of ISO 13528, Annex B2 in the next table: Methanol in %M/M r (Observed).3 reference method Horwitz.3 * R (ref. method).4 Table 4: Repeatability of subsamples #15231 The calculated repeatabilities of both samples are in agreement with the.3 times the reproducibility limits of the respective test methods. Therefore the homogeneity of each of the subsamples #1523 and #15231 was assumed. To each of the participating laboratories: 1 * 1 L bottle (labelled #1523) and 1 *.25 L bottle (labelled #15231) were sent on November 11, STABILITY OF THE SAMPLES The stability of Ethanol, packed in the amber glass bottles, was checked. The material was found sufficiently stable for the period of the proficiency test. 2.6 ANALYSES The participants were asked to determine on sample #1523: Acidity, Appearance, Copper, Density at 2 o C, Electrical conductivity at 25ºC, Inorganic Chloride as Cl, Involatile material content, Nitrogen, phe, Phosphorus, Sulphate, Sulphur and Water (coulometric and titrimetric). On sample #15231 was asked to determine: Ethanol, Acetaldehyde, Acetal, Acetone, n- Amylalcohol, sec-amylalcohol, tert-amylalcohol, Benzene, n-butanol, sec-butanol, tert-butanol, n-butyraldehyde, Crotonaldehyde, Cyclohexane, Cyclohexanol, Diacetyl, DEG, Dioxane, Ethylacetate, Ethylbenzene, ETBE, Furfural, n-heptane, n-hexanol, Isobutanol, Isopropanol, Methanol, 2-methyl-1-Butanol, 3-methyl-1-Butanol, sum of 2-methyl-1-Butanol and 3-methyl-1- Butanol, MEK, MTBE, MEG, MiBK, n-propanol, Toluene, m-xylene, o-xylene and p-xylene. To get comparable results a detailed report form, on which the units were prescribed as well as the required standards and a letter of instructions were prepared and made available on the data entry portal A SDS and a form to confirm receipt of the samples were added to the sample package. Fuel/Bio-Ethanol iis15c14 page 5 of 49

6 Institute for Interlaboratory Studies Spijkenisse, February RESULTS During four weeks after sample despatch, the results of the individual laboratories were gathered via the data entry portal The original data are tabulated per determination in appendix 1 of this report. The laboratories are presented by their code numbers. Directly after deadline, a reminder was sent to those laboratories that had not yet reported. Shortly after the deadline, the available results were screened for suspect data. A result was called suspect in case the Huber Elimination Rule (a robust outlier test) found it to be an outlier. The laboratories that produced these suspect data were asked to check the (raw data of the) reported results. Additional or corrected results have been used for data analysis and original results are placed under 'Remarks' in the result tables in appendix STATISTICS Statistical calculations were performed as described in the report iis Interlaboratory Studies: Protocol for the Organisation, Statistics and Evaluation (iis-protocol, April 214 version 3.3). For the statistical evaluation the unrounded (when available) figures were used instead of the rounded results. Results reported as < or > were not used in the statistical evaluation. First, the normality of the distribution of the various data sets per determination was checked by means of the Lilliefors-test a variant of the Kolmogorov-Smirnov test and by the calculation of skewness and kurtosis. Evaluation of the three normality indicators in combination with the visual evaluation of the graphic Kernel density plot, lead to judgement of the normality being either unknown, OK, suspect or not OK. After removal of outliers, this check was repeated. Not all data sets proved to have a normal distribution, in which cases the statistical evaluation of the results should be used with due care. Accordance to ISO 5725 (1986 and 1994) the original results per determination were submitted subsequently to Dixon, Grubbs and Rosner outlier tests. Outliers are marked by D(.1) for the Dixon test, by G(.1) or DG(.1) for the Grubbs test and by R(.1) for the Rosner General ESD test (see appendix 3, no.16). Stragglers are marked by D(.5) for the Dixon test, by G(.5) or DG(.5) for the Grubbs test and by R(.5) for the Rosner s test. Both outliers and stragglers were not included in the calculations of the averages and the standard deviations. For each assigned value, the uncertainty was determined in accordance with ISO Subsequently the calculated uncertainty was evaluated against the respective requirement based on the target reproducibility in accordance with ISO When the uncertainty passed the evaluation, no remarks are made in the report. However, when the uncertainty failed the evaluation it is mentioned in the report and it will have consequences for the evaluation of the test results. Finally, the reproducibilities were calculated from the standard deviations by multiplying them with a factor of 2.8. Page 6 of 49 Fuel/Bio-Ethanol iis15c14

7 Spijkenisse, February 216 Institute for Interlaboratory Studies 3.2 GRAPHICS In order to visualise the data against the reproducibilities from literature, Gauss plots were made, using the sorted data for each determination (see appendix 1). On the Y-axis the reported analysis results are plotted. The corresponding laboratory numbers are under the X- axis. The straight horizontal line presents the consensus value (a trimmed mean). The four striped lines, parallel to the consensus value line, are the +3s, +2s, -2s and -3s target reproducibility limits of the selected standard. Outliers and other data, which were excluded from the calculations, are represented as a cross. Accepted data are represented as a triangle. Furthermore, Graphs were made. This is a method for producing a smooth density approximation to a set of data that avoids some problems associated with histograms (see appendix 3; nos.14 and 15). Also a normal Gauss curve was projected over the Kernel Density Graph for reference. 3.3 Z-SCORES To evaluate the performance of the participating laboratories the z-scores were calculated. As it was decided to evaluate the performance of the participants in this proficiency test (PT) against the literature requirements, e.g. ASTM reproducibilities, the z-scores were calculated using a target standard deviation. This results in an evaluation independent of the spread of this interlaboratory study. The target standard deviation was calculated from the literature reproducibility by division with 2.8. When a laboratory did use a test method with a reproducibility that is significantly different from the reproducibility of the reference test method used in this report, it is strongly advised to recalculate the z-score, while using the reproducibility of the actual test method used, this in order to evaluate whether the reported test result is fit-for-use. The z-scores were calculated in accordance with: z (target) = (result - average of PT) / target standard deviation The z (target) scores are listed in the result tables in appendix 1. Absolute values for z<2 are very common and absolute values for z>3 are very rare. Therefore the usual interpretation of z-scores maybe as follows: z < 1 good 1 < z < 2 satisfactory 2 < z < 3 questionable 3 < z unsatisfactory Fuel/Bio-Ethanol iis15c14 page 7 of 49

8 Institute for Interlaboratory Studies Spijkenisse, February EVALUATION In this interlaboratory study, some problems with sample despatch were encountered due to several reasons. Five participants reported after the deadline and three participants did not report any result at all. Not all participants were able to report all requested parameters. Not all laboratories were able to perform all analyses requested. The 68 reporting laboratories did report 899 results. Observed were 39 outlying results, which is 4.3%. In proficiency studies, outlier percentages of 3% - 7.5% are normal. 4.1 EVALUATION PER TEST In this section, the results are discussed per sample and per test. The specified test methods and requirements were taken into account for explaining the observed differences when possible and applicable. These methods are also in the tables together with the reported data. The abbreviations, used in these tables, are listed in appendix 3. In the iis PT reports, ASTM methods are referred to with a number (e.g. D1613) and an added designation for the year that the method was adopted or revised (e.g. D1613-2). If applicable, a designation in parentheses is added to designate the year of reapproval (e.g. D (212)). In the results tables of Appendix 1 only the method number and year of adoption or revision will be used. For the components measured by Gas Chromatography the observed spreads were compared against EN15271 and/or the (strict) reproducibility limit estimated from the Horwitz equation. Not all original data sets proved to have a normal Gaussian distribution. These are referred to as not OK or suspect. The statistical evaluation of these data sets should be used with due care. Acidity: Appearance: This determination was problematic for a number of laboratories. Two statistical outliers were observed. However, the calculated reproducibility after rejection of the statistical outliers is in full agreement with the requirements of EN15491:7 and ASTM D1613:2(212). This determination was not problematic. All participants agreed about the appearance of sample #1523 as clear and free of suspended matter. Chloride, Inorganic: The determination of this component may be problematic, depending on the test method used by the laboratory. A known concentration of Chloride was added to the samples (see 2.4) and therefore the minimum chloride concentration able to be determined was known (4.48 mg/kg=5.45 mg/kg-.97 mg/kg (R EN15492) ). However, 17 of the 33 laboratories reported a concentration lower than 4.48 mg/kg and these test results were rejected prior to statistical analysis. Also one statistical outlier was observed. The calculated reproducibility after rejection of the suspect data is not in agreement with the requirements of EN15492:12, but it is in agreement with the requirements of ASTM D7319. The average recovery of Inorganic Chloride Page 8 of 49 Fuel/Bio-Ethanol iis15c14

9 Spijkenisse, February 216 Institute for Interlaboratory Studies (theoretical increment of 5.45 mg Cl/kg) may be good: less than 95% (the actual blank chloride content is unknown). Copper: Almost all laboratories reported a less than test result. Therefore no statistical conclusions were drawn. Density at 2 o C: This determination was problematic for a number of laboratories. Three statistical outliers were observed. However, the calculated reproducibility after rejection of the statistical outliers is in good agreement with the requirements of ISO12185:96. Electrical Conductivity: This determination was problematic. One statistical outlier was observed. The calculated reproducibility after rejection of the statistical outlier is not in agreement with the requirements of EN15938:1. Involatile matter: All test results were below the application range of the method EN15691:9 (1 25 mg/1ml). Therefore no significant conclusions were drawn. Nitrogen: This determination was problematic. One statistical outlier was observed. The calculated reproducibility after rejection of the statistical outlier is not at all in agreement with the requirements of D4629:12. Four laboratories reported a false negative test result. phe: It is known (see ref. 17) that in general in a phe determination with a LiCl electrode, the observed values are lower than in the case other types of electrodes are used. In last year PT on REN/Food Ethanol (iis14c11) a bimodal distribution was observed. Therefore, in this PT, besides the phe also the type of electrode used in the determination was requested to be reported by the participants. A bimodal distribution was also visible for the phe values on sample #1523. Therefore, it was decided to evaluate the reported test results per type of electrolyte used. phe (KCl): This determination was not problematic. No statistical outliers were observed. The calculated reproducibility is in full agreement with the requirements of D4629:14. phe (LiCl): This determination was problematic for a number of laboratories. Three statistical outliers according the Huber (robust) outlier test were observed. The calculated reproducibility after rejection of the statistical outliers is in agreement with the requirements of EN1549:7. Phosphorous: Sulphate: All test results were near or below the application range of method EN15487:7 ( mg/kg). Therefore no statistical conclusions were drawn. The consensus value of the group was below application range of the methods EN15492:12 (1 2 mg/l) and ASTM D7319:9 (1 5 mg/l). Therefore no statistical conclusions were drawn. Two laboratories reported a false positive test result. Fuel/Bio-Ethanol iis15c14 page 9 of 49

10 Institute for Interlaboratory Studies Spijkenisse, February 216 Total Sulphur: Water: GC general: Although the sulphur concentration was below the application ranges of the test methods EN15485:7 (7 2 mg/kg) and EN15486:7 (5 2 mg/kg), this determination may not be problematic. No statistical outliers were observed and the calculated reproducibility is in good agreement with the estimated requirements of EN15485:7 and EN15486:7, but not in agreement with the requirements of ASTM D5453:9. The coulometric or the titrimetric Karl Fisher method can be used for this determination. In total four statistical outliers were observed. The calculated reproducibility for the coulometric method after rejection of the statistical outliers is in full agreement with the requirements of EN15489:7 and ASTM E164:12. For the titrimetric Karl Fisher method the calculated reproducibility is in good agreement with the requirements of ASTM E23:8. In previous round robins it became clear that the test result reported for the Ethanol content is depending on the test method used by the laboratory. The test method EN15721 used a different definition for Ethanol, than ASTM D551 does. Therefore, it was decided in this proficiency test to request the ethanol content for both definitions. Ethanol (EN15721): After exploring the effect of the purity calculation as reported by the participants, it was decided to determine a consensus value for Ethanol, based on the test results of the participants that reported to have used EN15721 only. In EN15721 the purity (the ethanol content) is defined as: Ethanol (incl. higher alcohols) = 1% - impurity% - methanol %, where the higher alcohols consequently are not included in impurity%. This determination was very problematic. Two statistical outliers were observed. The calculated reproducibility after rejection of the statistical outliers is not at all in agreement with the requirements of EN15721:13. Higher Alcohols (EN15721): After exploring the effect of the purity calculation as reported by the participants, it was decided to use a consensus value for Higher Alcohols, based on the test results of the participants that reported to have used EN15721 only. In EN15721 the higher alcohol content is defined as: the sum of n-propanol%, n-butanol%, sec-butanol%, isopropanol%, 2-methyl- 1-butanol% and 3-methyl-1-butanol%. This determination was not problematic. No statistical outliers were observed. The calculated reproducibility is in agreement with the requirements of EN15721:13. Impurities (EN15721): This determination was very problematic. The group appears to be bimodally divided. After investigation it turned out that one group of laboratories did include the higher alcohols in the impurity result. This is not in accordance with EN15721 (chapters 1 and 8.3). In EN15721 the impurity content is defined as: content of all components except for Methanol% and the higher alcohols %. Page 1 of 49 Fuel/Bio-Ethanol iis15c14

11 Spijkenisse, February 216 Institute for Interlaboratory Studies When the two groups of test results are evaluated separately, no statistical outliers were observed and both calculated reproducibilities are not in agreement with the estimated reproducibility limits using the Horwitz equation. Methanol: This determination was problematic. Four statistical outliers were observed. The calculated reproducibility after rejection of the statistical outliers is not in agreement with the estimated requirements calculated using the Horwitz equation. When using standard EN15721:13 a negative value for the reproducibility is found at this concentration level. Ethanol (D551): This determination was not problematic. One statistical outlier was observed. The calculated reproducibility after rejection of the statistical outlier is in agreement with the requirements of D551:12e1. Acetaldehyde: Acetal: n-butanol: Ethylacetate: Isobutanol: This determination may be problematic. Two statistical outliers were observed. The calculated reproducibility after rejection of the statistical outliers is not at all in agreement with the estimated reproducibility using the Horwitz equation. This determination may be problematic. One statistical outlier was observed. The calculated reproducibility after rejection of the statistical outlier is not in agreement with the estimated reproducibility using the Horwitz equation. The consensus value found was near or below the detection limit of the test methods used, therefore no significant conclusions were drawn. Two statistical outliers were observed. This determination may be problematic. Two statistical outliers were observed. The calculated reproducibility after rejection of the statistical outliers is not in agreement with the estimated reproducibility using the Horwitz equation. This determination may be problematic. No statistical outliers were observed. The calculated reproducibility is not in agreement with the estimated reproducibility using the Horwitz equation. 2-Me-1-Butanol: This determination may be problematic. No statistical outliers were observed. The calculated reproducibility is not in agreement with the estimated reproducibility using the Horwitz equation. 3-Me-1-Butanol: This determination may be very problematic. One statistical outlier was observed. The calculated reproducibility after rejection of the statistical outlier is not at all in agreement with the estimated reproducibility using the Horwitz equation. Sum of This determination may be not problematic. Two statistical outliers were 2-Me-1-Butanol observed. Eight laboratories reported the sum but did not report the test results and for the individual components. The calculated reproducibility after rejection of 3-Me-1-Butanol the statistical outliers is in full agreement with the estimated reproducibility using the Horwitz equation. Fuel/Bio-Ethanol iis15c14 page 11 of 49

12 Institute for Interlaboratory Studies Spijkenisse, February 216 n-propanol: Toluene: o-xylene: This determination may be problematic. No statistical outliers were observed. The calculated reproducibility is not in agreement with the estimated reproducibility using the Horwitz equation. This determination may be problematic. One statistical outlier was observed. The calculated reproducibility after rejection of the statistical outlier is not in agreement with the estimated reproducibility using the Horwitz equation. This determination may be problematic. Two statistical outliers were as observed. The calculated reproducibility after rejection of the statistical outlier is not in agreement with the estimated reproducibility using the Horwitz equation. Other GC components: The concentrations of the components Acetone, n-amylalcohol, sec- Amylalcohol, tert-amylalcohol, Benzene, sec-butanol, tert-butanol, n-butyraldehyde, Crotonaldehyde, Cyclohexane, Cyclohexanol, Diacetyl, DEG, Dioxane, Ethylbenzene, ETBE, Furfural, n-heptane, n-hexanol, Isopropanol, MEK, MTBE, MEG, MiBK, m-xylene and p-xylene, were all near or below the detection limit. Therefore no significant conclusions were drawn for these components. 4.2 PERFORMANCE EVALUATION FOR THE GROUP OF LABORATORIES A comparison has been made between the reproducibility as declared by the relevant standard and the reproducibility as found for the group of participating laboratories. The average results per sample, calculated reproducibilities and reproducibilities derived from literature standards (in casu ASTM or EN standards) or the Horwitz equation are compared in the next table. Parameter unit n average 2.8 *sd R R (lit) Acidity as Acetic acid mg/kg Appearance 52 Clear n.a. n.a. Chloride as Cl, Inorganic mg/kg Copper mg/kg 28 <.7 n.a. n.a. Density at 2 o C kg/l Electrical conductivity μs/cm Involatile material content mg/1 ml (.2) Nitrogen mg/kg phe (KCl) phe (LiCl) Phosphorus mg/l 23 <.2 n.a. n.a. Sulphate mg/kg (.3) Total Sulphur mg/kg Water coulometric mg/kg Water titrimetric %M/M Table 5: Reproducibilities of sample #1523 Results between brackets should used with care, because the average was near or below the application range. Page 12 of 49 Fuel/Bio-Ethanol iis15c14

13 Spijkenisse, February 216 Institute for Interlaboratory Studies Parameter Unit n average 2.8 *sd R R (lit) Ethanol (EN15721) %M/M Higher Alcohols (EN15721) %M/M Impurities - group 1 %M/M Impurities - group 2 %M/M Methanol %M/M Ethanol (D551) %M/M Acetaldehyde %M/M Acetal %M/M n-butanol %M/M (.2) Ethylacetate %M/M Isobutanol %M/M Me-1-Butanol %M/M Me-1-Butanol %M/M Sum 2-Me-1-BuOH+3-Me-1-BuOH %M/M n-propanol %M/M Toluene %M/M o-xylene %M/M Table 6: Reproducibilities of sample #15231 Results between brackets should used with care, because the average was near or below the application range. Without further statistical calculations, it can be concluded that for most of the tests there is not a good compliance of the group of participating laboratories with the relative standards. The tests, that are problematic, have been discussed in paragraph COMPARISON OF THE PROFICIENCY TEST OF DECEMBER 215 WITH PREVIOUS PTS December 215 November 214 November 213 November 212 Number of reporting labs Number of results reported Statistical outliers Percentage outliers 4.3% 5.1% 4.7% 6.2% Table 7: Comparison with previous proficiency tests. In proficiency tests, outlier percentages of 3% - 7.5% are quite normal. The performance of the determinations of the proficiency tests was compared against the requirements of the respective standards. The conclusions are given the following table: Fuel/Bio-Ethanol iis15c14 page 13 of 49

14 Institute for Interlaboratory Studies Spijkenisse, February 216 Determination December 215 November 214 November 213 November 212 Acidity as Acetic Acid +/- +/- + +/- Chloride as Cl, Inorganic (+) Density at 2 o C Electric conductivity Involatile Matter (--) (--) (--) (--) Nitrogen Phosphorus as P n.e. (+/-) (--) (-) Sulphate (--) (--) (--) ++ Total Sulphur Water coulometric +/- +/ Water titrimetric Ethanol (EN15721) -- n.e. n.e. n.e. Higher Alcohols (EN15721) - n.e. n.e. n.e. Impuritites (EN15721) -- n.e. n.e. n.e. Methanol Ethanol (D551) n.e. Acetaldehyde n.e. n.e. Acetal Acetone n.e. n.e. n.e. n.e, n-amylalcohol n.e. n.e. n.e. n.e. sec-amylalcohol n.e. n.e. n.e. n.e. tert-amylalcohol n.e. n.e. n.e. n.e. Benzene n.e. n.e. +/- n.e. n-butanol (--) sec-butanol n.e. n.e. n.e. n.e. tert-butanol n.e. n.e. n.e. n.e. n-butyraldehyde n.e. n.e. n.e. n.e. Crotonaldehyde n.e. n.e. n.e. n.e. Cyclohexane n.e. n.e. n.e. n.e. Cyclohexanol n.e. n.e. n.e. n.e. Diacetyl n.e. n.e. n.e. n.e. Diethylene glycol (DEG) n.e. n.e. n.e. n.e. Dioxane n.e. n.e. n.e. n.e. Ethylacetate Ethylbenzene n.e. n.e. n.e. n.e. ETBE n.e. n.e. n.e. n.e. Furfural n.e. n.e. n.e. n.e. n-heptane n.e. n.e. n.e. n.e. n-hexanol n.e. n.e. n.e. n.e. Isobutanol Isopropanol n.e. n.e. n.e. n.e. 2-Methyl-1-butanol Methyl-1-butanol Sum 3-Me- + 2-Me-1-BuOH n.e. Methyl-ethyl Ketone (MEK) n.e. n.e. n.e. n.e. MTBE n.e. n.e. n.e. n.e. Monoethylene glycol (MEG) n.e. n.e. n.e. n.e. MiBK n.e. n.e. n.e. n.e. Page 14 of 49 Fuel/Bio-Ethanol iis15c14

15 Spijkenisse, February 216 Institute for Interlaboratory Studies n-propanol -- +/- +/- + Toluene -- n.e. n.e. n.e. m-xylene n.e. n.e. n.e. n.e. o-xylene -- n.e. n.e. n.e. p-xylene n.e. n.e. n.e. n.e. Table 8: comparison determinations against the standard Results between brackets are compared with the spread of the previous round robin The performance of the determinations against the requirements of the respective standards is listed in the above table. The following performance categories were used: ++: group performed much better than the standard + : group performed better than the standard +/-: group performance equals the standard - : group performed worse than the standard -- : group performed much worse than the standard n.e.: not evaluated Fuel/Bio-Ethanol iis15c14 page 15 of 49

16 Institute for Interlaboratory Studies Spijkenisse, February 216 APPENDIX 1 Determination of Acidity as Acetic Acid on sample #1523; results in mg/kg EN D D D C D D D D EN D D D D D D D D D D D D D EN C,R(.1) D EN15491 < EN EN15491 < D EN EN EN EN15491 <3 C EN EN C EN C EN D EN15491 < EN EN15491 < EN EN ISO1388/ EN EN C EN EN C EN EN C,R(.5) EN EN EN C EN C EN C EN15491 < EN C D D EN C normality OK n 52 outliers 2 mean (n) 21.2 st.dev. (n) R(calc.) R(EN15491:7) 13.7 Application range: 3.15 mg/kg Compare R(D1613:2) 14. Lab 12: reported.24 mg/kg Lab 333: reported <.3 mg/kg Lab 334: reported.17 mg/kg Lab 444: reported.4 mg/kg Lab 496: reported.23 mg/kg Lab 511: reported.194 mg/kg Lab 14: reported.185 mg/kg Lab 1563: reported.2 mg/kg Lab 1656: reported.1 mg/kg Lab 1727: reported.17 mg/kg Lab 1835: reported.23 mg/kg Lab 1276: first reported.16 Lab 1996: first reported Page 16 of 49 Fuel/Bio-Ethanol iis15c14

17 Spijkenisse, February 216 Institute for Interlaboratory Studies Determination of Appearance on sample #1523; 52 D4176 Pass D4176 Pass Visual Clear & Bright Visual C&B E268 PASS D4176 Clear and Bright Visual Clear and Bright D4176 Clear & Bright E268 Pass E268 Pass E268 Pass D4176 Clear and Bright E268 Pass EN15769 PASS EN15769 Pass D268 Pass E268 PASS Visual CLEAR LIQUID Visual Clear and bright E268 Pass D4176 Clear and Bright Visual Clear and bright EN15769 clear&colourless Visual Clear & colorless E268 clear & bright Visual clear Visual clear and bright EN15769 Clear and colourless Visual Br&Cl Visual clear and colourless D4176 Bright and clear EN15769 Clear and Colourless Visual Clear Visual Clear and Bright Visual clear Visual Clear & Bright E268 pass EN15769 Clear and Colourless EN15769 Clear and colourless EN15769 Clear and colourless EN15769 Pass EN15769 Clear and Bright EN15769 Pass EN15769 Clear & coloured EN15769 C&C Visual Clean&colourless EN15769 clear. colourless EN15769 C&B Visual C&B EN15769 CCL EN15769 C&B D4176 C&B normality n.a. n 52 outliers n.a. mean (n) Clear and Colourless Fuel/Bio-Ethanol iis15c14 page 17 of 49

18 Institute for Interlaboratory Studies Spijkenisse, February 216 Determination of Chlorides, Inorganic as Cl on sample #1523; results in mg/kg D D INH-55 <.5 ex, see 4.1 < D D EN ex, see EN ex, see D ex, see EN C D ex, see EN D512 < EN EN15492 <.1 ex, see 4.1 < EN EN ex, see EN EN ex, see EN EN ex, see EN C, ex, see EN ex, see EN15484 < EN EN R(.1) EN D ex, see EN C, ex, see EN EN ex, see EN C, ex, see EN EN D ex, see EN EN C, ex, see normality OK n 17 outliers 1 (+17 excl) Spike: mean (n) Recovery = <95% st.dev. (n).428 R(calc.) R(EN15492:12).891 Compare R(D7319:13) Lab 36: first reported 8.56 Lab 468: first reported 1.13 Lab 922: first reported <3. Lab 1276: first reported 4.12 Lab 1996: first reported 8.53 Lab 663: reported a false negative test result Lab 179: reported a false negative test result Page 18 of 49 Fuel/Bio-Ethanol iis15c14

19 Spijkenisse, February 216 Institute for Interlaboratory Studies Determination of Copper on sample #1523; results in mg/kg 52 D D1688 < D1688 < D1688 < D1688 < UOP389 < D EN15488 < D1688 < D1688 < D1688 < EN15488 < EN EN15488 < EN15488 < EN EN15488 < EN15837 < EN EN EN EN15488 < EN15837 < EN EN15488 < EN15488 < D1688 < EN15488 < normality n.a. n 28 outliers n.a. mean (n) <.7 st.dev. (n) n.a. R(calc.) n.a. R(EN15488:7) n.a. Fuel/Bio-Ethanol iis15c14 page 19 of 49

20 Institute for Interlaboratory Studies Spijkenisse, February 216 Determination of Density at 2 o C on sample #1523; results in kg/l 52 D ISO D D D D R(.1) D D D D D D D D D D D D D D ISO D ISO C D C D ISO D ISO D ISO C,R(.1) ISO ISO ISO ISO ISO ISO ISO ISO ISO ISO D ISO ISO D D ISO INH ISO D ISO D D R(.1) ISO ISO D D D ISO D D C ISO D D D ISO C.22 normality OK n 63 outliers 3 mean (n) st.dev. (n).63 R(calc.).18 R(ISO12185:96).5 Lab 23: first reported Lab 511: reported 79.7 kg/l Lab 14: reported 79. kg/l Lab 1161: reported kg/l Lab 1996: first reported Page 2 of 49 Fuel/Bio-Ethanol iis15c14

21 Spijkenisse, February 216 Institute for Interlaboratory Studies Determination of Electrical conductivity at 25 C on sample #1523; results in µs/cm EN EN D EN EN EN15938 > EN EN EN EN EN EN EN EN D EN EN EN EN C,R(.1) EN EN EN EN NBR EN EN normality OK n 24 outliers 1 mean (n) st.dev. (n).3469 R(calc.).971 R(EN15938:1).698 Lab 1656: first reported Fuel/Bio-Ethanol iis15c14 page 21 of 49

22 Institute for Interlaboratory Studies Spijkenisse, February 216 Determination of Involatile material content on sample #1523; results in mg/1ml EN15691 < EN D D D D D EN EN D D EN15691 < EN EN15691 < EN EN15691 < EN15691 < EN EN D EN EN15691 < EN EN15691 < EN EN15691 < EN EN D1353 < EN15691 < EN EN EN EN EN EN15691 < EN15691 < D D R(.1) normality OK n 26 outliers 1 mean (n) st.dev. (n).8247 R(calc.) 2.39 R(EN15691:9) (.234) Application range : 1 25 mg/1ml Page 22 of 49 Fuel/Bio-Ethanol iis15c14

23 Spijkenisse, February 216 Institute for Interlaboratory Studies Determination of Nitrogen on sample #1523; results in mg/kg 52 D D D D G(.1) D D4629 <.3 < D4629 <1. < D D D D D4629 <.3 < D in house D4629 <.3 < D D D D D D D4629 <.1 <-3.5 normality OK n 16 outliers 1 mean (n) st.dev. (n).5291 R(calc.) R(D4629:12).896 Application range:.3 1 mg/kg Lab, 333, 142 and 1996 reported a false negative test result? Fuel/Bio-Ethanol iis15c14 page 23 of 49

24 Institute for Interlaboratory Studies Spijkenisse, February 216 Determination of phe (KCl) on sample #1523; lab method Elect. value mark z(targ) lab method Elect. value mark z(targ) D6423 KCl D6423 KCl D6423 KCl D6423 ORION D6423 KCl D6423 KCl D6423 KCl D6423 KCl D6423 KCl D6423 KCl D6423 KCl D6423 KCl D6423 KCl D6423 KCl EN1549 KCl In house KCl D6423 KCl D6423 KCl D6423 KCl normality OK n 19 outliers mean (n) st.dev. (n).4169 R(calc.) R(D6423:14) Page 24 of 49 Fuel/Bio-Ethanol iis15c14

25 Spijkenisse, February 216 Institute for Interlaboratory Studies Determination of phe (LiCl) on sample #1523; lab method Elect. value mark z(targ) lab method Elect. value mark z(targ) EN1549 LiCl EN1549 EtOH- Trode EN1549 LiCl 6.7 H EN1549 LiCl 7.23 H EN1549 LiCl 7.31 H EN1549 LiCl EN1549 LiCl EN1549 LiCl EN normality OK n 6 outliers 3 mean (n) st.dev. (n).1165 R(calc.).326 R(EN1549:7) Fuel/Bio-Ethanol iis15c14 page 25 of 49

26 Institute for Interlaboratory Studies Spijkenisse, February 216 Determination of Phosphorus on sample #1523; results in mg/l D3231 < D3231 < UOP389 < EN15487 < EN15487 < EN15487 < EN EN15487 < EN15487 < EN C EN EN15487 < EN EN15837 < EN EN15487 < EN EN EN15487 < EN15487 < EN EN15487 < EN15487 < normality unknown n 23 outliers n.a. mean (n) <.2 st.dev. (n) n.a. R(calc.) n.a. R(EN15487:7) n.a. Application range: mg/l Lab 1276: first reported.55 Page 26 of 49 Fuel/Bio-Ethanol iis15c14