GEOCHEMICAL ROUND 9
PROFICIENCY TESTING PROGRAM
FEBRUARY 2014
REPORT NO. 845
ACKNOWLEDGMENTS
PTA wishes to gratefully acknowledge the technical assistance that was provided for this
program by Ms J Hwende of Bureau Veritas Australia Pty Ltd.
©
COPYRIGHT PROFICIENCY TESTING AUSTRALIA 2014
PO Box 1122, Archerfield BC, QLD, 4108, Australia
CONTENTS
1. Foreword
1
2. Program Features and Design
1
3. Statistical Format
2
4. PTA and Technical Advisor‟s comments
5
5. Outlier Results
7
6. Reference
7
APPENDIX A – Results and Data Analysis
Aluminium
A1.1
Arsenic
A2.1
Calcium
A3.1
Iron
A4.1
Magnesium
A5.1
Manganese
A6.1
Phosphorus
A7.1
Potassium
A8.1
Silicon
A9.1
Sodium
A10.1
Sulphur
A11.1
Titanium
A12.1
Vanadium
A13.1
Loss on Ignition
A14.1
APPENDIX B – Sample Homogeneity
Homogeneity Testing
B1
APPENDIX C – Documentation
Instructions to Participants
C1
Results Sheet
C4
1
1.
Foreword
This report summarises the results of a proficiency testing program on the analysis of
geochemical samples. The exercise was conducted in December 2013 / January
2014 by Proficiency Testing Australia (PTA). The Program Coordinator was Mrs K
Weller and the Technical Advisor was Ms J Hwende, Bureau Veritas Australia Pty
Ltd. This report was authorised by Ms W Fajloun, PTA Quality Coordinator. The main
aim of the program was to assess laboratories‟ abilities to competently perform the
prescribed analyses.
2.
Program Features and Design
2.1
Each laboratory was randomly allocated a unique code number for the program to
ensure confidentiality of results. Reference to each laboratory in this report is by code
number only.
2.2
Participants were provided with one iron ore sample.
2.3
Laboratories were provided with the "Instructions to Participants" and "Results Sheet"
(see Appendix C) and asked to report total analysis of the elements listed below:
Aluminium
Calcium
Iron
Magnesium
Arsenic
2.4
Al2O3
CaO
Fe
MgO
As
Manganese
Phosphorus
Potassium
Silicon
Vanadium
Mn
P
K2O
SiO2
V2O5
Sodium
Sulphur
Titanium
Loss on Ignition
Na2O
S
TiO2
LOI
A total of 10 separate laboratories received samples for the program. All laboratories
returned results by the due date for inclusion in the final report.
Participants included laboratories from Australia, India and Turkey.
2.5
Results (as reported by participants), and where relevant, corresponding summary
statistics (i.e. number of results, median, normalised interquartile range, robust
coefficient of variation, minimum, maximum, range and uncertainty of the median) are
presented in Appendix A.
2.6
A robust statistical approach, using z-scores, was utilised to assess laboratories‟
testing performance (see Section 3). Robust z-scores and z-score charts relevant to
each test are presented in Appendix A.
The document entitled Guide to Proficiency Testing Australia, 2012 (reference [1])
defines the statistical terms and details the statistical procedures referred to in this
report.
2
2.7
Previously, the bulk material was analysed and tested for homogeneity. Based on the
results of this testing it was considered that the samples utilised for this program were
homogeneous. As such, any results later identified as outliers could not be attributed
to any notable sample variability. Please refer to Appendix B.
3.
Statistical Format
For each test the following information is given, where appropriate:
- a table of results and calculated z-scores;
- a list of summary statistics; and
- ordered z-score charts.
3.1
Outlier Results and Z-scores
In order to assess laboratories‟ testing performance, a robust statistical approach,
using z-scores, was utilised. Z-scores give a measure of how far a result is from the
consensus value (i.e. the median), and gives a "score" to each result relative to the
other results in the group.
A z-score close to zero indicates that the result agrees well with those from other
laboratories. Whereas, a z-score with an absolute value greater than or equal to 3.0
is considered to be an outlier and is marked by the symbol “§”.
Where relevant, each determination was examined for outliers with all methods
pooled. Table B on page 7 summarises the outlier results detected.
3
3.2
Results Tables and Summary Statistics
Each of these tables contains the results returned by each laboratory and where
appropriate, the robust z-score calculated for each result.
Results have been entered exactly as reported by participants. That is, laboratories
which did not report results to the precision (i.e. number of significant figures)
requested on the Results Sheet have not been rounded to the requested precision
before being included in the statistical analysis.
Where relevant, a list of summary statistics appears at the bottom of each of the
tables of results and consists of:
- the number of results for that test/sample (No. of Results);
- the median of these results, i.e. the middle value (Median);
- the normalised interquartile range of the results (Normalised IQR);
- the robust coefficient of variation, expressed as a percentage (Robust CV) - i.e. 100
x Normalised IQR / Median;
- the minimum and maximum laboratory results;
- the range (Maximum - Minimum); and
- the Uncertainty of the Median.
Please see reference [1] for further details on these robust summary statistics.
3.3
Ordered Z-score Charts
On these charts each laboratory's robust z-score is shown, in order of magnitude, and
is marked with its code number. From these charts, each laboratory can readily
compare its performance relative to the other laboratories.
These charts contain solid lines at +3 and -3, so that outliers are clearly identifiable as
those laboratories whose "bar" extends beyond these "cut-off" lines. The y-axis of
these charts has been limited, so very large z-scores appear to extend beyond the
chart boundary.
Further details for the interpretation of these diagrams are given in reference [1].
Please also refer to this document for a glossary of terms.
4
TABLE A: SUMMARY STATISTICS
Analysis
No. of Results
Median (%)
Normalised IQR
Uncertainty
(Median) (%)
Aluminium (oxide)
10
0.1753
0.0186
0.0074
Arsenic
3
Calcium (oxide)
9
0.6930
0.0162
0.0068
Iron
9
65.710
0.170
0.071
Magnesium (oxide)
9
0.2740
0.0297
0.0124
Manganese
8
0.0908
0.0064
0.0028
Phosphorus
8
0.0081
0.0024
0.0011
Potassium (oxide)
6
0.0125
0.0011
0.0005
Silicon (oxide)
10
4.537
0.044
0.018
Sodium (oxide)
4
Sulphur
7
0.0030
0.0024
0.0011
Titanium (oxide)
6
0.0140
0.0055
0.0028
Vanadium (oxide)
4
Not Calculated1
LOI (at 1000ºC)
8
Not Calculated2
1
Not Calculated1
Not Calculated1
Statistical analysis has not been performed due to the small number of results returned.
Statisical analysis has not been performed on these results as they were not normally
distributed.
2
5
4.
PTA and Technical Advisor’s Comments
This program was aimed at laboratories routinely analysing iron ore samples for
major elements. The comments presented in this section are general in nature.
4.1
Overall performance
The general performance was satisfactory. Most laboratories used a Lithium
Tetraborate/Metaborate fusion dissolution/digestion technique with an XRF finish. An
unusually wide variation between laboratories using XRF for Iron (Fe) analysis was
noted in this round.
Loss on Ignition analysis proved to be incomparable amongst the laboratories.
Outliers for Magnesium (MgO) and Aluminium (Al2O3) that need investigation were
noted.
4.2
Outliers
Four out of ten laboratories exhibited outliers. Table B shows outlier results and the
techniques used.
Laboratories are encouraged to investigate and eliminate the cause for the outliers
and anomalies, in particular:
Laboratory 8 outliers for Iron (Fe) and Magnesium (MgO) where method used
should be capable of the analysis, therefore the laboratory needs to review
their process. The same applies for laboratory 1 outlier for Aluminium (Al2O3).
Laboratory 9 outliers for Iron (Fe) and Manganese (Mn) where there may be
incomplete digestion/dissolution in the 4 acid digestion technique, the
laboratory should review their process.
4.3
Measurement Uncertainty (MU)
Most laboratories made a good effort and quantified MU.
4.4
Z-score (Interlaboratory Performance)
Whilst the z-score gives an indication of where each laboratory stands in comparison
to their peers (median), laboratories with z-scores:
greater than 2.0 for any element - the laboratory should review the technique
and calibration for that element.
greater than or equal to 3.0 for any element - the laboratory should seriously
review the method for that element (except in the case of a typographical or
calculation error).
4.5
Duplicates
For the most part, duplicate results for most laboratories were reasonable.
6
4.6
Technique Bias
Based on the z-score analysis, there is no evidence to support technique bias.
4.7
Method Code
All laboratories provided method codes for except laboratories 3 and 7 for Loss on
Ignition.
4.8
Metrological Traceability and Measurement Uncertainty of Assigned Values
Consensus values (median) derived from participants‟ results are used in this
program. These values are not metrologically traceable to an external reference.
The sample chosen for this program was provided by Brammer Standard Company,
Inc. (Houston, USA). The bulk samples were crushed and divided into small plastic
bottles and sent to NATA/PTA (Sydney) via Graham B. Jackson Pty Ltd.
As the assigned value for this program is the median of the results submitted by the
participants, the uncertainty of the median has been calculated for each analysis
(where relevant) and is tabulated in Table A on page 4, and also in the summary
statistics tables in Appendix A.
4.9
Analysis of Results by Method Groups
In order for methods to be grouped for analysis, PTA requires more than 10 sets of
results from the same method group. As there were less than 10 results submitted for
each method, reliable conclusions cannot be drawn from analysing grouped methods
on this occasion. Therefore, results from all method groups have been pooled for
analysis.
7
5.
Outlier Results
Laboratories reporting outlier results are listed in the following table:
TABLE B: OUTLIER RESULTS
Element
Lab Code
Bias
Method Code
Dissolution/Digestion
Technique
Aluminium
1
+ve
6 - XRF
Borate Flux
Calcium
No outliers reported
8
-ve
6 - XRF
fusion
9
-ve
1 - ICPOES
4AD
Magnesium
8
+ve
6 - XRF
fusion
Manganese
9
-ve
1 - ICPOES
4AD
Iron
Phosphorus
No outliers reported
Potassium
No outliers reported
Silicon
10
+ve
11 - UV
Spectrophotometric
sodium tetraborate fusion +
nitric acid
Sulphur
8
+ve
6 - XRF
fusion
Titanium
No outliers reported
Note: Z-scores could not be determined for Arsenic, Sodium and Vanadium due to the
small number of results returned or for Loss on Ignition due to the results not being
normally distributed.
6.
Reference
[1]
Guide to Proficiency Testing Australia, 2012. (This document can be found on
the PTA website, www.pta.asn.au)
APPENDIX A
Results and Data Analysis
Aluminium
Arsenic
Calcium
Iron
Magnesium
Manganese
Phosphorus
Potassium
Silicon
Sodium
Sulphur
Titanium
Vanadium
Loss on Ignition
A1.1
A2.1
A3.1
A4.1
A5.1
A6.1
A7.1
A8.1
A9.1
A10.1
A11.1
A12.1
A13.1
A14.1
A1.1
Aluminium (%)
(as Al2O3)
Lab Result 1 Result 2 Average Absolute
Code
(%)
(%)
(%)
Difference
MU
Detection Method
Limit
Code
Dissolution/Digestion
Technique
Robust
z-score
3.41 §
1
0.234
0.243
0.239
0.004
0.059
0.005
6
Borate Flux
2
0.176
0.175
0.176
0.001
0.018
0.01%
6
Borate Fusion
0.01
3
0.163
0.166
0.165
0.003
#
0.01
6
#
-0.58
4
0.120
0.130
0.125
0.010
±0.0833 at
0.13
#
7
EDTA-titrmetric
method (HCl acid)
-2.71
5
0.17
0.18
0.175
0.01
0.01%
0.05
6
Fused Bead (12:22
Li2B4O7: LiBO2 +12.8%
Na2NO3)
-0.01
6
0.173
0.173
0.173
0.000
2%
0.01
6
XRF-Fusion / Lithium
Meta-Tetraborate
-0.12
7
0.18
0.20
0.190
0.02
#
0.01
6
#
0.79
8
0.183
0.184
0.184
0.001
0.009
#
6
fusion
0.44
9
0.194
0.192
0.193
0.002
0.01
0.02
1
0.96
10
0.128
0.128
0.128
0.000
0.02
0.019
3
Peroxide fusion
digestion with HCl and
HNO3
Notes:
§ denotes an outlier.
# indicates no result returned.
Summary Statistics
No. results
Median
Norm IQR
Robust CV
Min
Max
Range
Uncertainty (Median)
10
0.1753
0.0186
10.6%
0.125
0.239
0.114
0.0074
-2.55
A1.2
A2.1
Arsenic (%)
Lab Result 1 Result 2 Average Absolute
Code
(%)
(%)
(%)
Difference
MU
Detection Method
Limit
Code
Dissolution/Digestion
Technique
2
0.001
0.002
0.0015
0.001
0.0001
0.005%
6
6
0.0006
0.0009
0.0008
0.0003
10%
0.001
6
7
nd
nd
N/A
N/A
#
0.005
6
Borate fusion
XRF-Fusion / Lithium
Meta-Tetraborate
#
9
0.0011
0.0017
0.0014
0.0006
0.0010
0.0005
1
4AD
Due to the small number of numerical results returned (3) for this test, results have been
tabulated for information purposes only. No statistical analysis has been conducted.
Note:
# indicates no result returned.
A3.1
Calcium (%)
(as CaO)
Lab Result 1 Result 2 Average Absolute
Code
(%)
(%)
(%)
Difference
MU
Detection Method
Limit
Code
Dissolution/Digestion
Technique
Robust
z-score
1
0.687
0.686
0.687
0.001
0.037
0.005
6
Borate Flux
-0.40
2
0.692
0.694
0.693
0.002
0.0692
0.01%
6
Borate Fusion
0.00
3
0.690
0.690
0.690
0.000
#
0.01
6
#
-0.19
5
0.66
0.64
0.650
0.02
0.01%
0.05
6
Fused Bead (12:22
Li2B4O7: LiBO2 +12.8%
Na2NO3)
-2.66
6
0.699
0.700
0.700
0.001
2%
0.01
6
XRF-Fusion / Lithium
Meta-Tetraborate
0.40
7
0.71
0.70
0.705
0.01
#
0.01
6
#
0.74
8
0.73
0.74
0.735
0.01
0.04
#
6
fusion
2.60
9
0.722
0.724
0.723
0.002
0.02
0.005
1
1.86
10
0.656
0.658
0.657
0.002
0.03
0.020
3
4AD
digestion with HCl and
HNO3
Note:
# indicates no result returned.
Summary Statistics
No. results
Median
Norm IQR
Robust CV
Min
Max
Range
Uncertainty (Median)
9
0.6930
0.0162
2.3%
0.650
0.735
0.085
0.0068
-2.23
A3.2
A4.1
Iron (%)
Lab Result 1 Result 2 Average Absolute
Code
(%)
(%)
(%)
Difference
MU
Detection Method
Limit
Code
Dissolution/Digestion
Technique
Robust
z-score
1
66.01
66.06
66.04
0.05
0.01
0.005
6
Borate Flux
1.91
2
65.79
65.73
65.76
0.06
0.6579
0.01%
6
Borate Fusion
0.29
3
65.69
65.73
65.71
0.04
#
0.1
6
#
0.00
4
65.97
65.95
65.96
0.02
±0.2473 at
69.44
#
7
SnCl2 - HgCl2 K2Cr2O7 titrametric
method (HCl acid)
1.47
5
>30
>30
*
*
0.1%
0.05
6
Fused Bead (12:22
Li2B4O7 : LiBO2
+12.8% Na2NO3)
*
6
65.73
65.73
65.73
0.00
1%
0.01
6
XRF-Fusion / Lithium
Meta-Tetraborate
0.12
7
65.7
65.7
65.70
0.0
#
0.01
6
#
-0.06
8
63.1
63.0
63.05
0.1
3.1
#
6
fusion
-15.61 §
9
48.59
48.58
48.59
0.01
1.17
0.01
1
10
65.58
65.55
65.57
0.03
0.12
#
7
Notes:
* statistics could not be performed for this result (Laboratory 5).
§ denotes an outlier.
# indicates no result returned.
Summary Statistics
No. results
Median
Norm IQR
Robust CV
Min
Max
Range
Uncertainty (Median)
9
65.710
0.170
0.3%
48.59
66.04
17.45
0.071
4AD
-100.47 §
sodium peroxide fusion
-0.85
+ HCl
A4.2
A5.1
Magnesium (%)
(as MgO)
Lab Result 1 Result 2 Average Absolute
Code
(%)
(%)
(%)
Difference
MU
Detection Method
Limit
Code
Dissolution/Digestion
Technique
Robust
z-score
1
0.260
0.250
0.255
0.01
0.032
0.005
6
Borate Flux
-0.64
2
0.275
0.273
0.274
0.002
0.0275
0.01%
6
Borate Fusion
0.00
3
0.306
0.303
0.305
0.003
#
0.01
6
#
1.03
5
0.23
0.24
0.235
0.01
0.03%
0.10
6
Fused Bead (12:22
Li2B4O7 : LiBO2
+12.8% Na2NO3)
-1.31
6
0.288
0.290
0.289
0.002
2%
0.01
6
XRF-Fusion / Lithium
Meta-Tetraborate
0.50
7
0.26
0.27
0.265
0.01
#
0.01
6
#
-0.30
8
1.11
1.12
1.115
0.01
#
0.05
6
fusion
9
0.242
0.247
0.245
0.005
0.007
0.002
1
10
0.282
0.284
0.283
0.002
0.03
0.009
3
4AD
digestion with HCl +
HNO3
Notes:
§ denotes an outlier.
# indicates no result returned.
Summary Statistics
No. results
Median
Norm IQR
Robust CV
Min
Max
Range
Uncertainty (Median)
9
0.2740
0.0297
10.8%
0.235
1.115
0.880
0.0124
28.30 §
-0.99
0.30
A5.2
A6.1
Manganese (%)
Lab Result 1 Result 2 Average Absolute
Code
(%)
(%)
(%)
Difference
MU
Detection Method
Limit
Code
Dissolution/Digestion
Technique
Robust
z-score
1
0.091
0.091
0.091
0.000
0.012
0.002
6
Borate Flux
0.04
2
0.090
0.091
0.091
0.001
0.009
0.01%
6
Borate Fusion
-0.04
3
0.096
0.096
0.096
0.000
#
0.01
6
#
0.82
4
0.110
0.100
0.105
0.010
±0.049 at
0.11
0.1%
7
Mn is oxidised in presence of
AgNO3 & Ammonium
persulphate-HMnO4-NaArsentie titrimetic Method
2.23
5
0.10
0.10
0.100
0.00
0.02%
0.07
6
Fused Bead (12:22
Li2B4O7 : LiBO2
+12.8% Na2NO3)
1.45
6
0.090
0.090
0.090
0.000
5%
0.001
6
XRF-Fusion / Lithium
Meta-Tetraborate
-0.12
7
0.089
0.089
0.089
0.000
#
0.002
6
#
-0.27
9
0.056
0.061
0.059
0.005
0.006
0.001
1
4AD
Notes:
§ denotes an outlier.
# indicates no result returned.
Summary Statistics
No. results
Median
Norm IQR
Robust CV
Min
Max
Range
Uncertainty (Median)
8
0.0908
0.0064
7.0%
0.059
0.105
0.047
0.0028
-5.05 §
A6.2
A7.1
Phosphorus (%)
Lab Result 1 Result 2 Average Absolute
Code
(%)
(%)
(%)
Difference
MU
Detection
Limit
Method
Code
Dissolution/Digestion
Technique
Robust
z-score
1
0.0083
0.0079
0.008
0.0004
0.0061
0.002
6
Borate Flux
0.02
2
0.010
0.010
0.010
0.010
0.001
0.002%
6
Borate Fusion
0.80
3
0.005
0.005
0.005
0.005
#
0.002
6
#
-1.25
0.002%
7
Ammonium
Phosphomolybdate
titrimetric method
(HCl acid)
1.21
*
4
0.010
0.012
0.011
0.002
±0.007
at 0.01
5
<0.02
<0.02
*
*
0.01%
<0.02
6
Fused Bead (12:22
Li2B4O7 : LiBO2
+12.8% Na2NO3)
6
0.008
0.008
0.008
0.000
5%
0.002
6
XRF-Fusion / Lithium
Meta-Tetraborate
-0.02
7
0.007
0.009
0.008
0.002
#
0.001
6
#
-0.02
9
0.010
0.012
0.011
0.002
0.01
0.005
1
11 (UV
4AD
1.21
10
0.0060
0.0059
0.006
0.0001
0.001
0.0012
spectrophotometric
determination)
sodium tetraborate
fusion + HCl
-0.86
Notes:
* statistics could not be performed for this result (Laboratory 5).
# indicates no result returned.
Summary Statistics
No. results
Median
Norm IQR
Robust CV
Min
Max
Range
Uncertainty (Median)
8
0.0081
0.0024
30.2%
0.005
0.011
0.006
0.0011
A7.2
A8.1
Potassium (%)
(as K2O)
Lab Result 1 Result 2 Average Absolute
Code
(%)
(%)
(%)
Difference
MU
Detection Method
Limit
Code
Dissolution/Digestion
Technique
Robust
z-score
1
0.011
0.012
0.012
0.001
0.035
0.005
6
Borate Flux
-0.95
2
0.013
0.014
0.014
0.001
0.0013
0.01%
6
Borate Fusion
0.95
3
0.012
0.013
0.013
0.001
#
0.002
6
0.00
5
<0.01
<0.01
*
*
0.005%
<0.01
6
6
0.012
0.012
0.012
0.000
5%
0.001
6
7
0.012
0.013
0.013
0.001
#
0.002
6
#
Fused Bead (12:22
Li2B4O7 : LiBO2
+12.8% Na2NO3)
XRF-Fusion / Lithium
Meta-Tetraborate
#
9
0.0141
0.0143
0.014
0.0002
0.002
0.002
1
4AD
Notes:
* statistics could not be performed for this result (Laboratory 5).
# indicates no result returned.
Summary Statistics
No. results
Median
Norm IQR
Robust CV
Min
Max
Range
Uncertainty (Median)
6
0.0125
0.0011
8.5%
0.012
0.014
0.003
0.0005
*
-0.47
0.00
1.61
A8.2
A9.1
Silicon (%)
(as SiO2)
Lab Result 1 Result 2 Average Absolute
Code
(%)
(%)
(%)
Difference
MU
Detection
Limit
Method
Code
Dissolution/Digestion
Technique
Robust
z-score
1
4.52
4.52
4.52
0.00
0.196
0.005
6
Borate Flux
-0.37
2
4.569
4.586
4.58
0.017
0.4569
0.01%
6
Borate Fusion
0.93
3
4.526
4.540
4.53
0.014
#
0.01
6
#
-0.08
4
4.41
4.45
4.43
0.04
±0.2023
at 4.45
#
7
Gravimetric Method
(HCl acid)
-2.41
5
4.54
4.51
4.53
0.03
0.2%
0.05
6
Fused Bead (12:22
Li2B4O7 : LiBO2
+12.8% Na2NO3)
-0.26
6
4.56
4.56
4.56
0.00
2%
0.01
6
XRF-Fusion / Lithium
Meta-Tetraborate
0.53
7
4.58
4.59
4.59
0.01
#
0.01
6
#
1.10
8
4.50
4.52
4.51
0.02
#
0.22
6
fusion
-0.60
9
4.510
4.570
4.54
0.060
0.14
0.01
1
11 (UV
Peroxide fusion
0.08
10
4.68
4.70
4.69
0.02
0.10
0.0010
spectrophotometric
determination)
Notes:
§ denotes an outlier.
# indicates no result returned.
Summary Statistics
No. results
Median
Norm IQR
Robust CV
Min
Max
Range
Uncertainty (Median)
10
4.537
0.044
1.0%
4.43
4.69
0.26
0.018
sodium tetraborate
fusion + Nitric Acid
3.47 §
A9.2
A10.1
Sodium (%)
(as Na2O)
Lab Result 1 Result 2 Average Absolute
Code
(%)
(%)
(%)
Difference
MU
Detection Method
Limit
Code
Dissolution/Digestion
Technique
2
0.023
0.024
0.024
0.001
0.0023
0.01%
6
Borate Fusion
3
0.085
0.092
0.089
0.007
#
0.02
6
6
0.028
0.029
0.029
0.001
10%
0.005
6
7
nd
nd
N/A
N/A
#
0.01
6
#
XRF-Fusion / Lithium
Meta-Tetraborate
#
9
0.0179
0.0284
0.023
0.0105
0.02
0.005
1
4AD
Due to the small number of numerical results returned (4) for this test, results have been
tabulated for information purposes only. No statistical analysis has been conducted.
Note:
# indicates no result returned.
A11.1
Sulphur (%)
Lab Result 1 Result 2 Average Absolute
Code
(%)
(%)
(%)
Difference
MU
Detection Method
Limit
Code
Dissolution/Digestion
Technique
Robust
z-score
1
0.0012
0.0016
0.001
0.0004
0.0240
0.002
6
Borate Flux
-0.68
2
0.000
0.001
0.001
0.001
0
0.002%
6
Borate Fusion
-1.06
3
0.003
0.003
0.003
0.000
#
0.002
6
#
0.00
4
0.004
0.003
0.004
0.001
±0.0025 at
0.004
0.0004%
10
High Heat combustionInfrared Absorption
method
0.21
5
<0.01
<0.01
*
*
0.005%
<0.01
6
Fused Bead (12:22
Li2B4O7 : LiBO2
+12.8% Na2NO3)
6
0.0009
0.0008
0.001
0.0001
5%
0.001
6
XRF-Fusion / Lithium
Meta-Tetraborate
7
nd
nd
*
*
#
0.001
6
#
8
0.011
0.012
0.012
0.001
#
0.0006
6
fusion
9
0.003
0.005
0.004
0.002
0.005
0.002
1
4AD
Notes:
* statistics could not be performed for these results (Laboratories 5 and 7).
§ denotes an outlier.
# indicates no result returned.
Summary Statistics
No. results
Median
Norm IQR
Robust CV
Min
Max
Range
Uncertainty (Median)
7
0.0030
0.0024
78.8%
0.001
0.012
0.011
0.0011
*
-0.91
*
3.59 §
0.42
A11.2
A12.1
Titanium (%)
(as TiO2)
Lab Result 1 Result 2 Average Absolute
Code
(%)
(%)
(%)
Difference
MU
Detection Method
Limit
Code
Dissolution/Digestion
Technique
Robust
z-score
1
0.0140
0.0120
0.013
0.0020
0.005
0.005
6
Borate Flux
-0.18
2
0.012
0.011
0.012
0.001
0.0012
0.01%
6
Borate Fusion
-0.45
3
0.019
0.020
0.020
0.001
#
0.005
6
1.00
5
<0.05
<0.05
*
*
0.002%
<0.01
6
6
0.012
0.011
0.012
0.001
5%
0.01
6
7
0.02
0.01
0.015
0.01
#
0.01
6
#
Fused Bead (12:22
Li2B4O7 : LiBO2
+12.8% Na2NO3)
XRF-Fusion / Lithium
Meta-Tetraborate
#
9
0.0185
0.0188
0.019
0.0003
0.007
0.001
1
Peroxide fusion
Notes:
* statistics could not be performed for this result (Laboratory 5).
# indicates no result returned.
Summary Statistics
No. results
Median
Norm IQR
Robust CV
Min
Max
Range
Uncertainty (Median)
6
0.0140
0.0055
39.4%
0.012
0.020
0.008
0.0028
*
-0.45
0.18
0.84
A12.2
A13.1
Vanadium (%)
(as V2O5)
Lab Result 1 Result 2 Average Absolute
Code
(%)
(%)
(%)
Difference
MU
Detection Method
Limit
Code
Dissolution/Digestion
Technique
2
0.003
0.004
0.0035
0.001
0.0003
0.005%
6
6
0.0029
0.0027
0.0028
0.0002
10%
0.002
6
7
0.007
0.003
0.0050
0.004
#
0.002
6
Borate Fusion
XRF-Fusion / Lithium
Meta-Tetraborate
#
9
0.0021
0.0025
0.0023
0.0004
0.0005
0.00005
1
4AD
Due to the small number of results returned (4) for this test, results have been tabulated for
information purposes only. No statistical analysis has been conducted.
Note:
# indicates no result returned.
A14.1
Loss on Ignition (%)
(at 1000ºC)
Lab Result 1 Result 2 Average Absolute
Code
(%)
(%)
(%)
Difference
MU
Detection
Limit
Method
Code
Dissolution/Digestion
Technique
1
0.13
0.11
0.120
0.01
0.02
0.005
7
N/A
2
0.080
0.080
0.080
0.08
0.008
0.01%
10
Borate Fusion
3
0.11
0.10
0.105
0.02
#
#
#
#
#
7
Ignition Method
4
0.21
0.23
0.220
0.07
±0.0138 at
0.23
6
0.07
0.07
0.070
0.03
5%
0.01
10
TGA
7
0.01
0.01
0.010
0.03
#
-100
#
11 (in house
#
8
0.012
0.019
0.016
0.00
ND
#
method based
on classical
methods)
ignition at 1000ºC
9
0.1991
0.1980
0.199
0.06
0.05
0.01
7
Muffle Furnace
No statistical analysis has been conducted due to the results not being normally distributed.
Results have been tabulated for information purposes only.
Note:
# indicates no result returned.
APPENDIX B
Sample Homogeneity
Homogeneity Testing
B1
B1
Homogeneity Testing
The ATSM Dichromate Titrimetry method E1028 - 93 was used for all the total iron analysis. Six
individual lots were prepared after the entire batch was pulverised and mixed and 10 repeat
analysis were performed by Brammer Standard Company, Inc. from the composite lots. Due to the
nature of the samples they are considered to remain homogeneous provided they were well
shaken before analysis (as outlined in the instructions).
The bulk material was randomly sampled and tested for iron content. The material was found to be
homogeneous for iron content.
APPENDIX C
Documentation
Instructions to Participants
C1
Results Sheet
C4
C1
PROFICIENCY TESTING AUSTRALIA
Proficiency Testing Program
Geochemical Testing – Round 9
INSTRUCTIONS TO PARTICIPANTS
Please read instructions carefully BEFORE commencing testing.
To ensure that the results of this program can be analysed properly, participants are asked to
carefully note the following:
1. Samples
One iron ore sample with approximately 50g in a glass bottle has been provided for each
laboratory.
Please shake sample prior to analysis.
2. Testing
The testing should commence as soon as possible after receipt of the sample.
Report total analysis of major and trace elements listed below on a „dry‟ basis by the technique
that gives the best detection limit for each element.
Aluminium
Arsenic
Calcium
Iron
Magnesium
Al2O3
As
CaO
Fe
MgO
Manganese
Phosphorus
Potassium
Silicon
Sodium
Mn
P
K2O
SiO2
Na2O
Test and report Loss on Ignition result (at 1000ºC)
3. Safety
The samples are for laboratory use only.
All required safety procedures should be followed.
Page 1 of 3
Sulphur
Titanium
Vanadium
S
TiO2
V2O5
Loss on Ignition LOI
C2
4. Reporting
Please submit results on the Results Sheet provided.
Duplicate results are requested.
In addition to reporting the results, specify the dissolution/digestion technique used. Also record the
method of analysis using the attached codes (refer to page 3). Details should be provided of any
method techniques that are used that are not specified in the table on page 3.
Results should be quoted in elemental or oxide form as in listed in 2 (on previous page) and on the
results sheet.
Please report each element to the units (%) along with your laboratory‟s detection limit for that
analysis.
Laboratories are also requested to calculate and report an estimate of uncertainty of
measurement for each reported measurement result.
All estimates of uncertainty of measurement must be given as a 95% confidence interval
(coverage factor k 2). Please note that MU will not be used to evaluate participant
performance in this program.
The following significant figures are recommended for reporting :
XX.XX%, X.XX%, 0.XXX%, 0.00XX%.
5. Please return results no later than FRIDAY 10 JANUARY 2014 to:
Kathy Weller
Proficiency Testing Australia
PO Box 1122
Archerfield BC QLD 4108
phone: +61 7 3721 7373
fax: +61 7 3217 1844
email: [email protected]
6. For this program your laboratory has been allocated the code number shown on the results
sheet. All reference to your laboratory in reports associated with this program will be by this
code number, thus ensuring confidentiality of results.
Page 2 of 3
C3
Analysis Method Codes to be used for the Results Sheets
Method Technique
Inductively coupled plasma atomic emission spectrometry
Inductively coupled plasma mass spectrometry
Atomic absorption spectrometry
Flame
Graphite furnace
Hydride generation
X-ray fluorescence spectrometry
Classical wet chemical analysis
Colorimetric
Neutron activation analysis
Leco combustion analysis
Other – please specify
Please use a Method Code for each element tested.
Page 3 of 3
Method Code
1
2
3
4
5
6
7
8
9
10
11
C4
PROFICIENCY TESTING AUSTRALIA
Geochemical – Round 9 - Proficiency Testing Program
Results Sheet
Lab Code:
Analysis
Aluminium,
Al2O3
Arsenic,
As
Calcium,
CaO
Iron,
Fe
Magnesium,
MgO
Manganese,
Mn
Phosphorus,
P
Potassium,
K2O
Silicon,
SiO2
Sodium,
Na2O
Sulphur,
S
Titanium,
TiO2
Vanadium,
V2O5
Loss on
Ignition (at
1000ºC)
Result 1
Result 2
Units
Detection
Limit
Dissolution/
Digestion Technique
(Please Specify)
Method
Code
%
%
%
%
%
%
%
%
%
%
%
%
%
%
MU* Laboratories’ Uncertainty of Measurement. Please report in the same units as the
results for each element.
Return no later than FRIDAY 10 JANUARY 2014, to:
Kathy Weller, Proficiency Testing Australia.
PO Box 1122, Archerfield BC QLD 4108. Australia.
phone: +61 7 3721 7373, fax: +61 7 3217 1844, email: [email protected]
Page 1 of 1
MU*
- End of Report -