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Results of Proficiency Test Propylene Oxide
September 2008 Organised by: Institute for Interlaboratory Studies (iis) Spijkenisse, the Netherlands Authors: Ing. W. Leung Correctors: Ing. S. Lagendijk & dr. R.G. Visser Report: iis08C08X November 2008
Spijkenisse, November 2008 Institute for Interlaboratory Studies
Propylene Oxide: iis08C08X page 2 of 27
CONTENTS 1 INTRODUCTION ..................................................................................................................................... 3 2 SET UP .................................................................................................................................................... 3 2.1 QUALITY SYSTEM ................................................................................................................................. 3 2.2 PROTOCOL............................................................................................................................................. 3 2.3 CONFIDENTIALITY STATEMENT ......................................................................................................... 3 2.4 SAMPLES ................................................................................................................................................ 4 2.5 ANALYSES.............................................................................................................................................. 4 3 RESULTS................................................................................................................................................. 5 3.1 STATISTICS ............................................................................................................................................ 5 3.2 GRAPHICS .............................................................................................................................................. 6 3.3 Z-SCORES .............................................................................................................................................. 6 4 EVALUATION .......................................................................................................................................... 6 4.1 EVALUATION PER TEST....................................................................................................................... 7 4.2 PERFORMANCE EVALUATION FOR THE GROUP OF LABORATORIES........................................ 8 4.3 COMPARISON OF THE PROFICIENCY TEST OF SEPTEMBER 2008 WITH THE PREVIOUS PT 9
Appendices: 1. Data and statistical results............................................................................................................. 10 2. Details of gas chromatographic conditions ................................................................................. 25 3. List of number of participants......................................................................................................... 26 4. Abbreviations and literature........................................................................................................... 27
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1 INTRODUCTION
On request of several laboratories, the Institute for Interlaboratory Studies decided to organize again a proficiency test for Propylene Oxide (PO) during the annual proficiency testing program 2008/2009. In this international interlaboratory study 13 laboratories in 8 different countries have participated. See appendix 3 for a list of participants in alphabetical country order. In this report the results of the proficiency test are presented and discussed.
2 SET UP
The Institute for Interlaboratory Studies (iis) in Spijkenisse, The Netherlands, was the organiser of this proficiency test and decided to send two identical samples (2*500 mL 70% filled, labelled #0851) to the participants. The participants were requested to report rounded and unrounded results. The unrounded results were preferably used for statistical evaluation.
2.1 QUALITY SYSTEM
The Institute for Interlaboratory Studies in Spijkenisse, the Netherlands, has implemented a quality system based on ISO guide 43 and ILAC-G13:2000. This ensures 100% confidentially of participant’s data. Also customer’s satisfaction is measured on a regular basis by sending out questionnaires.
2.2 PROTOCOL
The protocol followed in the organisation of this proficiency test was the one as described for proficiency testing in the report ‘iis Interlaboratory Studies: Protocol for the Organisation, Statistics and Evaluation’ of November 2008 (iis-protocol, version 3.1). The participants were asked to report the analytical results using the indicated units on the report form.
2.3 CONFIDENTIALITY STATEMENT All data present 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 of 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.
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2.4 SAMPLES The samples were prepared by a local producer of PO. The samples were obtained in colourless glass bottles of 500 mL filled for 70%. The homogeneity of the subsamples #0851 was checked by determination of Water in accordance with ASTM E203:01 and Density accordance with ASTM D4052:02e1 on 4 stratified random selected samples.
Density @ 20°C in kg/L Water in mg/kg
sample #0851-1 0.82922 26 sample #0851-2 0.82920 25 sample #0851-3 0.82918 23 sample #0851-4 0.82920 20
Table 1: homogeneity tests of subsamples #0851
From the results in table 1 the repeatability was calculated by multiplication of the standard deviations by 2.8:
Density @ 20°C in kg/L Water in mg/kg
r sample #0851 0.00005 7 Reference method ASTM D4052:02e1 ASTM E203:01 r(Reference method) 0.00010 80
Table 2: repeatability of subsamples #0851
The repeatabilities of the homogeneity tests for Water and Density were in agreement with the repeatabilities required by the respective standards. Therefore, homogeneities of the samples were assumed. Two samples of PO (500 mL, 70% filled, labelled #0851) were sent to each of the participating laboratories on September 16, 2008.
2.5 ANALYSES The participants were requested to determine on sample #0851. Acidity as Acetic Acid, Aldehydes as Propionaldehyde, Colour Pt/Co, Density @ 20 °C, Specific Gravity 20/20 °C/°C, Nonvolatile Matter, Water, Purity (on dry basis), Acetone, n-Butanol, t-Butanol, Ethylene Oxide, Methanol, Propane and Propene. To get comparable results a detailed report form, on which the units and the standard methods were printed, was sent together with each set of samples. Also a letter of instructions and a MSDS were added to the package.
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3 RESULTS During four weeks after sample despatch, the results of the individual laboratories were received. The original reported results are tabulated per determination in appendix 1 of this report. The laboratories are presented by their code numbers. Directly after deadline, a reminder fax was sent to those laboratories that had not yet reported any results at that moment. 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 results. Additional or corrected results are used for data analysis and original results are placed under 'Remarks' in the result tables in appendix 1.
3.1 STATISTICS Statistical calculations were performed as described in the report ‘iis Interlaboratory Studies: Protocol for the Organisation, Statistics and Evaluation’ of November 2003 (iis-protocol, version 3.0). 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. After removal of outliers this check was repeated. In case a data set does not have a normal distribution, the (results of the) statistical evaluation should be used with due care. In accordance to ISO 5725 (1986 and 1994) the original results per determination were submitted subsequently to Dixon and Grubbs outlier tests. Outliers are marked by D(0.01) for the Dixon test and by G(0.01) or DG(0.01) for the Grubbs test. Stragglers are marked by D(0.05) for the Dixon test and by G(0.05) or DG(0.05) for the Grubbs test. Both outliers and stragglers were not included in the calculations of the averages and the standard deviations. Finally, the reproducibilities were calculated from the standard deviations by multiplying these with a factor of 2.8.
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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 results are plotted. The corresponding laboratory numbers are under the X-axis. A straight line presents the average of the reported data. Two striped lines present the reproducibility limits of the selected standard, calculated as mean ± target reproducibility, parallel to the average line. Outliers and other data, which were excluded from the calculations, are represented as a cross. Accepted data are represented as a triangle. Furthermore, Kernel Density 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; nr.13 and 14)
3.3 Z-SCORES
To evaluate the performance of the participating laboratories the z-scores were calculated. Absolute values for z<2 are very common and absolute values for z>3 are very rare. Therefore the usual interpretation of z-scores is as follows:
| z | < 1 good 1 < | z | < 2 satisfactory 2 < | z | < 3 questionable | z | > 3 unsatisfactory As it was decided to evaluate the performance of the participants against the literature requirements, e.g. ASTM reproducibilities, the z-scores were calculated using a target standard deviation. This target standard deviation was calculated from the literature reproducibility by division with 2.8. 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.
4 EVALUATION
In this proficiency test no problems were encountered with the delivery of the samples to the participants. All participants submitted results. Two participants reported results after the final reporting date. The 13 reporting participants did send in 89 numerical results. Observed were 0 outlying results, which is 0 %. In proficiency studies outlier percentages of 3 % - 7.5 % are quite normal.
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4.1 EVALUATION PER TEST In this section the results are discussed per test. When no literature reproducibility was available, other target values were used. In those cases the Horwitz equation is used to estimate the target reproducibility. Not all data sets proved to have a normal distribution. Not normal distribution was found for Density. For this determination the statistical evaluation should be used with due care. Acidity: No analytical problems were observed. No results were outside the
reproducibility limits and the calculated reproducibility is in good agreement with the requirements of ASTM D1613:06.
Aldehydes: This determination is problematic. Three results were outside the
estimated reproducibility limits and the calculated reproducibility is not at all in agreement with the estimated reproducibility limits calculated using the Horwitz equation.
Colour Pt/Co: This determination is not problematic. No results were outside the
reproducibility limits and the calculated reproducibility is in good agreement with the requirement of ASTM D1209:05e1.
Density: No analytical problems were observed. No results were outside the
reproducibility limits and the calculated reproducibility is in good agreement with the requirements of ASTM D4052:02e1.
Specific Gravity: No analytical problems were observed. No results were outside the
reproducibility limits and the calculated reproducibility is in good agreement with the requirements of ASTM D4052:02e1.
Nonvolatile Matter: Too few numerical results were reported for meaningful conclusions.
Four laboratories reported a result and the others reported less than "<" results.
Water: This determination is problematic for two laboratories. No results were
outside the reproducibility limits. The calculated reproducibility is, after rejection of the statistical outliers, in full agreement with the requirements of ASTM D1364:07.
Purity (dry basis): Regretfully, no suitable standardized method exists with precision data.
Therefore it is not possible to draw significant conclusions. Acetone: Too few numerical results were reported for meaningful conclusions.
Only two participants reported a numerical value.
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n-Butanol: Too few numerical results were reported for meaningful conclusions. None of the participants reported a numerical value.
t-Butanol: Too few numerical results were reported for meaningful conclusions.
Only one participant reported a numerical value. Ethylene Oxide: Too few numerical results were reported for meaningful conclusions.
Only three participants reported a numerical value. Methanol: The determination is not problematic. No results were outside the
estimated reproducibility limits. The calculated reproducibility is almost in agreement with the strict estimated reproducibility calculated using the Horwitz equation.
Propane: Too few numerical results were reported for meaningful conclusions.
Only two participants reported a numerical value. Propene: Too few numerical results were reported for meaningful conclusions.
Only two participants reported a numerical value. 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 standards) or calculated using the Horwitz equation are compared in the next tables. Parameter unit n average 2.8 * sd R (lit)
Acidity as Acetic Acid %M/M 8 0.00085 0.00111 0.00140 Aldehydes as Propionaldehyde mg/kg 8 17.64 11.63 5.13 Colour Pt/Co 7 2.7 1.3 7.0 Density @20°C kg/L 11 0.82916 0.00029 0.00050 Specific Gravity 20/20 °C/°C kg/L 8 0.83067 0.00030 0.00050 Water mg/kg 9 36.30 16.97 36.15 Purity on dry basis %M/M 10 99.990 0.005 Unknown Methanol mg/kg 11 13.60 5.21 4.11
Table 3: reproducibilities of sample #0851
Without further statistical calculations it can be concluded that for most tests there is a good compliance of the group of participating laboratories with the relevant standards. The tests that are problematic have been discussed in paragraph 4.1.
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4.3 COMPARISON OF THE PROFICIENCY TEST OF SEPTEMBER 2008 WITH PREVIOUS PT’S
September 2008
May 2007
Number of reporting labs 13 13 Number of results reported 89 78
Statistical outliers 0 4 Percentage outliers 0.0 % 5.1 %
Table 4: 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: Parameter September
2008 May 2007
Acidity as Acetic Acid ++ ++ Aldehydes as Propionaldehyde -- -- Colour Pt/Co ++ ++ Density @20°C ++ + Specific Gravity 20/20 °C ++ n.d. Water ++ +/- Purity on dry basis n.e. n.e. Methanol -- ++
Table 5: comparison determinations against the standard requirements
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.d.: not determined n.e.: not evaluated
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APPENDIX 1 Determination of Acidity as Acetic Acid on sample #0851; results in %M/M
lab method value mark z(targ) remarks 311 D1613 0.0006 -0.49 323 D1613 0.0014 1.11 329 D1613 0.0008 -0.09 446 ----- ----- 613 ----- ----- 886 D1613 0.0006 -0.49
1117 D1613 0.00098 0.27 1305 ISO3682 0.00143 1.17 1509 D1613 0.00059 -0.51 1603 in house <0.001 ----- 1820 ----- ----- 1823 D1613 0.00036 -0.97 1828 ----- -----
normality OK n 8 outliers 0 mean (n) 0.00085 st.dev. (n) 0.000395 R(calc.) 0.00111 R(D1613:06) 0.00140
Kernel Density
0
200
400
600
800
1000
1200
-0.001 0 0.001 0.002 0.003
-0.001
-0.0005
0
0.0005
0.001
0.0015
0.002
0.0025
1823
1509
886
311
329
1117
323
1305
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Determination of Aldehydes as Propionaldehyde on sample #0851; results in mg/kg
lab method value mark z(targ) remarks 311 inh-294 17 -0.35 323 ----- ----- 329 ----- ----- 446 ----- ----- 613 ----- ----- 886 ----- -----
1117 in house 23.32 3.10 1305 in house 15.2 -1.33 1509 in house 19.6 1.07 1603 in house 11 -3.62 1820 16 U -0.90 Reported 0.0016 1823 in house 23 2.93 1828 16 U -0.90 Reported 0.0016
normality OK n 8 outliers 0 mean (n) 17.64 st.dev. (n) 4.152 R(calc.) 11.63 R(Horwitz) 5.13
Kernel Density
0
0.01
0.02
0.03
0.04
0.05
0.06
0.07
0.08
0.09
0.1
0 10 20 30 40
5
7
9
11
13
15
17
19
21
23
25
1603
1305
1820
1828
311
1509
1823
1117
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Determination of Colour Pt/Co on sample #0851;
lab method value mark z(targ) remarks 311 D1209 <5 ----- 323 D1209 <5 ----- 329 D1209 <5 ----- 446 D1209 <5 ----- 613 D1209 3 0.13 886 D1209 2 -0.27
1117 D1209 2 C -0.27 First reported 21 1305 in house 0 ex -1.07 Not a real result 1509 D1209 <5 ----- 1603 in house 3 0.13 1820 3 0.13 1823 D1209 2.7 0.01 1828 3 0.13
normality not OK n 7 outliers 0 mean (n) 2.7 st.dev. (n) 0.47 R(calc.) 1.3 R(D1209:05e1) 7.0
Kernel Density
0
0.1
0.2
0.3
0.4
0.5
0.6
-2 0 2 4 6
0
2
4
6
8
10
12
1305
1117
886
1823
1828
1820
613
1603
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Determination of Density @ 20 °C on sample #0851; results in kg/L
lab method value mark z(targ) remarks 311 D4052 0.8293 0.78 323 D4052 0.8291 -0.34 329 D4052 0.8291 -0.34 446 D4052 0.8293 0.78 613 D4052 0.82922 0.33 886 D4052 0.82915 -0.06
1117 D4052 0.8291 -0.34 1305 D4052 0.8291 -0.34 1509 D4052 0.8290 -0.90 1603 in house 0.8291 -0.34 1820 ----- ----- 1823 D4052 0.8293 0.78 1828 ----- -----
normality not OK n 11 outliers 0 mean (n) 0.82916 st.dev. (n) 0.000103 R(calc.) 0.00029 R(D4052:02e1) 0.00050
Kernel Density
0
500
1000
1500
2000
2500
3000
3500
0.8286 0.8288 0.829 0.8292 0.8294 0.8296
0.8284
0.8286
0.8288
0.829
0.8292
0.8294
0.8296
0.8298
1509
1305
1117
1603
323
329
886
613
1823
311
446
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Determination of Specific Gravity 20/20 °C/°C on sample #0851; results in kg/L
lab method value mark z(targ) remarks 311 D4052 0.8307 0.19 323 ----- ----- 329 ----- ----- 446 D4052 0.8308 0.75 613 ----- ----- 886 D4052 0.83064 -0.15
1117 ----- ----- 1305 D4052 0.8306 -0.37 1509 D4052 0.83049 -0.99 1603 in house 0.8306 -0.37 1820 ----- ----- 1823 D4052 0.8308 0.75 1828 0.8307 0.19
normality OK n 8 outliers 0 mean (n) 0.83067 st.dev. (n) 0.000106 R(calc.) 0.00030 R(D4052:02e1) 0.00050
Kernel Density
0
500
1000
1500
2000
2500
3000
3500
0.8302 0.8304 0.8306 0.8308 0.831 0.8312
0.83
0.8302
0.8304
0.8306
0.8308
0.831
0.8312
0.8314
1509
1305
1603
886
1828
311
446
1823
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Determination of Nonvolatile Matter on sample #0851; results in mg/100mL
lab method value mark z(targ) remarks 311 D1353 <1 ----- 323 D1353 <1 ----- 329 D1353 <1 ----- 446 D1353 <10 ----- 613 ----- ----- 886 D1353 0.1 -----
1117 D1353 <1 ----- 1305 in house 0 ----- 1509 D1353 0.4 ----- 1603 in house 1.0 ----- 1820 ----- ----- 1823 D1353 <0.5 ----- 1828 ----- -----
normality n.a. n 4 outliers 0 mean (n) n.a. st.dev. (n) n.a. R(calc.) n.a. R(D1353:03) n.a.
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Determination of Water on sample #0851; results in mg/kg
lab method value mark z(targ) remarks 311 D1364 30 -0.49 323 E1064 13 DG(0.05) -1.80 329 E203 15 DG(0.05) -1.65 446 E203 43 0.52 613 ----- ----- 886 ----- ----- 1117 E1064 38.3 0.15 1305 D1364 33.5 -0.22 1509 E1064 34.9 -0.11 1603 in house 37 0.05 1820 32 -0.33 1823 E1064 30 -0.49 1828 48 U 0.91 Reported 0.0048 normality OK n 9 outliers 2 mean (n) 36.30 st.dev. (n) 6.062 R(calc.) 16.97 R(D1364:07) 36.15
Kernel Density
0
0.01
0.02
0.03
0.04
0.05
0.06
0 20 40 60 80
0
10
20
30
40
50
60
70
80
323
329
1823
311
1820
1305
1509
1603
1117
446
1828
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Determination of Purity on dry basis on sampl #0851; results in %M/M
lab method value mark z(targ) remarks 311 inh-294 99.99 ----- 323 99.99 ----- 329 99.99 ----- 446 ----- ----- 613 ----- ----- 886 ----- -----
1117 in house 99.993 ----- 1305 99.987 ----- 1509 in house 99.992 ----- 1603 in house 99.99 ----- 1820 99.9891 ----- 1823 in house 99.992 ----- 1828 99.9892 -----
normality OK n 10 outliers 0 mean (n) 99.990 st.dev. (n) 0.0017 R(calc.) 0.005 R(lit) Unknown
Kernel Density
0
50
100
150
200
250
99.98 99.985 99.99 99.995 100
99.985
99.986
99.987
99.988
99.989
99.99
99.991
99.992
99.993
99.994
1305
1820
1828
1603
311
323
329
1823
1509
1117
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Determination of Acetone on sample #0851; results in mg/kg
lab method value mark z(targ) remarks 311 inh-294 <1 ----- 323 <5 ----- 329 <5 ----- 446 ----- ----- 613 ----- ----- 886 ----- -----
1117 in house <1 ----- 1305 4 ----- 1509 in house <5 ----- 1603 in house 11 ----- False positive result? 1820 ----- ----- 1823 in house <5 ----- 1828 <1 U ----- Reported <0.0001
normality n.a. n 2 outliers 0 mean (n) n.a. st.dev. (n) n.a. R(calc.) n.a. R(lit) Unknown
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Determination of n-Butanol on sample #0851; results in mg/kg
lab method value mark z(targ) remarks 311 inh-294 <1 ----- 323 <5 ----- 329 <5 ----- 446 ----- ----- 613 ----- ----- 886 ----- -----
1117 in house <1 ----- 1305 ----- ----- 1509 in house <5 ----- 1603 in house <3 ----- 1820 ----- ----- 1823 in house <5 ----- 1828 ----- -----
normality n.a. n n.a. outliers n.a. mean (n) n.a. st.dev. (n) n.a. R(calc.) n.a. R(lit) Unknown
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Determination of t-Butanol on sample #0851; results in mg/kg
lab method value mark z(targ) remarks 311 inh-294 <1 ----- 323 <5 ----- 329 <5 ----- 446 ----- ----- 613 ----- ----- 886 ----- -----
1117 in house <1 ----- 1305 0 ----- 1509 in house <5 ----- 1603 in house <3 ----- 1820 ----- ----- 1823 in house <5 ----- 1828 ----- -----
normality n.a. n 1 outliers 0 mean (n) n.a. st.dev. (n) n.a. R(calc.) n.a. R(lit) Unknown
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Determination of Ethylene Oxide on sample #0851; results in mg/kg
lab method value mark z(targ) remarks 311 inh-294 <1 ----- 323 <5 ----- 329 <5 ----- 446 ----- ----- 613 ----- ----- 886 ----- -----
1117 in house 2.4 ----- 1305 0 ----- 1509 in house <5 ----- 1603 in house <3 ----- 1820 ----- ----- 1823 in house 5 ----- 1828 ----- -----
normality n.a. n 3 outliers 0 mean (n) n.a. st.dev. (n) n.a. R(calc.) n.a. R(lit) Unknown
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Determination of Methanol on sample #0851; results in mg/kg
lab method value mark z(targ) remarks 311 inh-294 13 -0.41 323 10 -2.45 329 12 -1.09 446 ----- ----- 613 in house 14.2 0.41 886 ----- -----
1117 in house 13.1 -0.34 1305 14 0.27 1509 in house 13.3 -0.20 1603 in house 17 2.31 1820 14 U 0.27 Reported 0.0014 1823 in house 16 1.63 1828 13 U -0.41 Reported 0.0013
normality OK n 11 outliers 0 mean (n) 13.60 st.dev. (n) 1.860 R(calc.) 5.21 R(Horwitz) 4.11
Kernel Density
0
0.05
0.1
0.15
0.2
0.25
0.3
0 5 10 15 20 25
5
7
9
11
13
15
17
19
323
329
1828
311
1117
1509
1820
1305
613
1823
1603
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Determination of Propane on sample #0851; results in mg/kg
lab method value mark Z(targ) remarks 311 inh-294 <1 ----- 323 ----- ----- 329 ----- ----- 446 ----- ----- 613 ----- ----- 886 ----- -----
1117 in house <1 ----- 1305 0 ----- 1509 in house <5 ----- 1603 in house 9 ----- reported the sum of Propane + Propene 1820 ----- ----- 1823 in house <5 ----- 1828 ----- -----
normality n.a. n 2 outliers 0 mean (n) n.a. st.dev. (n) n.a. R(calc.) n.a. R(lit) Unknown
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Determination of Propene on sample #0851; results in mg/kg
lab method value mark Z(targ) remarks 311 inh-294 <1 ----- 323 ----- ----- 329 ----- ----- 446 ----- ----- 613 ----- ----- 886 ----- -----
1117 in house <1 ----- 1305 1 ----- 1509 in house <5 ----- 1603 in house 9 ----- reported the sum of Propane + Propene 1820 ----- ----- 1823 in house <5 ----- 1828 ----- -----
normality n.a. n 2 outliers 0 mean (n) n.a. st.dev. (n) n.a. R(calc.) n.a. R(lit) Unknown
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APPENDIX 2 Gas chromatographic conditions Lab
Column used Temp. program Cal. used Resp. fact. Rec.
311
CP-SIL 5 CB (60mx0.32mmx5.0µm) 30°C(6min)→(10°C/min)→100°C (1min) →(15°C/min)→225°C(1min)
Instd. 1 No
323
DBWAX (30mx0.32mmx0.5 µm) + CP-SIL 5 CB (50mX0.32mmX5µm)
35°C(5min)→80°C (5°C/min)→50°C isotherm
Exstd. 1.00 Yes
329
DB 1 & DB WAX 50°C isotherm & 35°C (5min)→80°C (5°C/min)
Exstd. 1 Yes
446
CP-PROPOX 30°C(10min)→70°C (10°C/min)→hold 1min Instd. 1 No
613
CP-SIL 5 CB (50mx0.32mmx5µm) 30°C(6min)→(10°C/min)→100°C (1min) →(15°C/min)→225°C(5min)
Exstd. --- ---
886
--- --- --- --- ---
1117 TCEP (50mx0.25mmx0.38µm) + CP-SIL 13 CB (50mx0.53mmx2.0µm)
30-8-10-100-40 Instd. 1000000(Kaiserfact. for C6,C7,C8)
No
1305
PORAPLOT 12@105°C→10°C/min→20@185°C Normalization with RF
1 ---
1509
CP TCEP (50mx0.25mmx0.4µm)
Int(40°C,5min),ramp(10°C/min,120°C,5min),tot.run(18 min)
Instd. 1.00 Yes
1603
(Propane,Propene,EthyleneOx.) 2x50m TCEP + others Petrocol 150m
(Propane,Propene,EthyleneOx.)35°C isotherm & others; 0°C/15min→2°C/min→ 140°C →10°C/min →190°C
Instd.
---
No
1820
--- --- --- --- ---
1823
TCEP (60MX0.25MMX0.4µm)
30°C(10min)→(5°C/min)→50°C (0min) →(10°C/min)→100°C(21min)
Instd.
1.3
Yes
1828
--- --- --- --- ---
Spijkenisse, November 2008 Institute for Interlaboratory Studies
Propylene Oxide: iis08C08X page 26 of 27
APPENDIX 3 List of participants per country
Number of laboratories Country
1 laboratory in AUSTRALIA
3 laboratories in BELGIUM
1 laboratory in GERMANY
1 laboratory in P.R. of CHINA
1 laboratory in SINGAPORE
1 laboratory in TAIWAN R.O.C.
4 laboratories in THE NETHERLANDS
1 laboratory in UNITED KINGDOM
Spijkenisse, November 2008 Institute for Interlaboratory Studies
Propylene Oxide: iis08C08X page 27 of 27
APPENDIX 4 Abbreviations: C = final result after checking of first reported suspect result D(0.01) = outlier in Dixon’s outlier test D(0.05) = straggler in Dixon’s outlier test G(0.01) = outlier in Grubbs’ outlier test G(0.05) = straggler in Grubbs’ outlier test DG(0.01) = outlier in Double Grubbs’ outlier test DG(0.05) = straggler in Double Grubbs’ outlier test E = error in calculations ex = excluded from calculations U = reported in different unit n.a. = not applicable W = result withdrawn on request of participant Literature: 1 iis Interlaboratory Studies, Protocol for the Organisation, Statistics & Evaluation, November 2008 2 ASTM E178-02 3 ASTM E1301-03 4 ISO 5725-86 5 ISO 5725, parts 1-6, 1994 6 M. Thompson and R. Wood, J. AOAC Int, 76, 926, (1993) 7 W.J. Youden and E.H. Steiner, Statistical Manual of the AOAC, (1975) 8 IP 367/96 9 DIN 38402 T41/42 10 P.L. Davies, Fr. Z. Anal. Chem, 331, 513, (1988) 11 J.N. Miller, Analyst, 118, 455, (1993) 12 IMPCA Methanol Reference Specifications, IMPCA, Brussels, January 2008. 13 ASTM E346-03e1 14 Analytical Methods Committee Technical brief, No4 January 2001. 15 The Royal Society of Chemistry 2002, Analyst 2002, 127 page 1359-1364, P.J. Lowthian and M. Thompson (see http://www.rsc.org/suppdata/an/b2/b205600n/).
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