Report 938 Waters Chem Round 186 Total Kjeldahl Nitrogen

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PTA wishes to gratefully acknowledge the technical assistance provided for this program by Dr M BuckleyProficiency Ltd (New Zealand) and to Global Proficiency Pty Ltd (Australia) for the supply and distribution of the samples.

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Waters Proficiency Testing

-

PTA wishes to gratefully acknowledge the technical assistance provided for this program by Dr M Buckley-Smith, GlobaProficiency Ltd (New Zealand) and to Global Proficiency Pty Ltd (Australia) for the supply and distribution of the samples.

PO B

Report No


Round

- Total Kjeldahl Nitrogen, Total Phosphorus

November 2015

PTA wishes to gratefully acknowledge the technical assistance provided for this program by Smith, Global Proficiency Ltd (New

Proficiency Ltd (New Zealand) and to Global Proficiency Pty Ltd (Australia) for the supply and distribution of the samples.

© Copyright

PO Box 7507

Report No


Round

Total Kjeldahl Nitrogen, Total Phosphorus

November 2015

Acknowledgments

PTA wishes to gratefully acknowledge the technical assistance provided for this program by l Proficiency Ltd (New

Proficiency Ltd (New Zealand) and to Global Proficiency Pty Ltd (Australia) for the supply and distribution of the samples.

© Copyright Proficiency Testing Australia

ox 7507 SILVERWATER

Report No


Round No.


November 2015

Acknowledgments

PTA wishes to gratefully acknowledge the technical assistance provided for this program by l Proficiency Ltd (New

Proficiency Ltd (New Zealand) and to Global Proficiency Pty Ltd (Australia) for the supply

Proficiency Testing Australia

SILVERWATER NSW

Report No . 938


o. 186


November 2015

Acknowledgments

PTA wishes to gratefully acknowledge the technical assistance provided for this program by l Proficiency Ltd (New Zealand). Also our thanks go to Global


Proficiency Testing Australia

NSW 2128

938


186

Total Kjeldahl Nitrogen, Total Phosphorus -

November 2015

PTA wishes to gratefully acknowledge the technical assistance provided for this program by . Also our thanks go to Global


Proficiency Testing Australia , 2015

2128, Australia


Total Kjeldahl Nitrogen,



2015

, Australia



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CONTENTS

1. Foreword ............................................................................................................................ 1

2. Program Features and Design ........................................................................................... 1

3. Statistical Format ............................................................................................................... 2

4. PTA and Technical Adviser’s Comments .......................................................................... 4

5. Outlier Results ................................................................................................................. 25

6. References ...................................................................................................................... 25

APPENDIX A – Results and Data Analysis

Total Kjeldahl Nitrogen .......................................................................................................... A1

Total Phosphorus .................................................................................................................. A7

APPENDIX B – Sample Homogeneity and Stability

Homogeneity and Stability Testing ........................................................................................ B1

APPENDIX C – Documentation

Instructions to Participants .................................................................................................... C1

Method Codes ....................................................................................................................... C3

Results Sheet ........................................................................................................................ C6

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1. Foreword

This report summarises the results of a proficiency testing program on the determination of Total Kjeldahl Nitrogen and Total Phosphorus in waters. This is round 186 in a planned series of programs involving the analysis of chemical and physical parameters of waters. The exercise was conducted in September 2015 by Proficiency Testing Australia (PTA). The main aim of the program was to assess laboratories’ abilities to competently perform the prescribed analyses. The Program Coordinator was Mrs D Mihaila and the Technical Adviser was Dr M Buckley-Smith, Global Proficiency Ltd (New Zealand). This report was authorised by Mrs F Watton, PTA Quality – Business Development Manager.

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. Please note that a number of laboratories reported more than one set of results and, therefore, their code numbers (with letter) could appear several times in the same data set.

2.2 Laboratories were provided with the "Instructions to Participants" and "Results Sheet"

(see Appendix C). Laboratories were requested to perform the tests according to their routine methods.

2.3 Participants were provided with three plastic vials (labelled PTA 1, PTA 2 and PTA 3)

containing artificial potable water concentrates for testing of Total Kjeldahl Nitrogen and Total Phosphorus.

2.4 A total of 37 laboratories received samples, comprising:

- 30 Australian participants; and

- 7 overseas participants, including:

- China (1), Indonesia (2), Malaysia (1), Namibia (1), New Zealand (1), Romania (1).

Of these 37 laboratories, 4 were unable to submit results by the due date. 2.5 Results (as reported by participants) with corresponding summary statistics (i.e.

number of results, median, normalised interquartile range, uncertainty of the median, robust coefficient of variation, minimum, maximum and range) are presented in Appendix A (for each sample and for each of the analyses performed).

2.6 A robust statistical approach, using z-scores, was utilised to assess laboratories’

testing performance (see Section 3). Robust z-scores and ordered z-score charts relevant to each test are presented in Appendix A.

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The document entitled Guide to Proficiency Testing Australia, 2014 (reference [1]) defines the statistical terms and details the statistical procedures referred to in this report.

2.7 A tabulated listing of laboratories (by code number) identified as having outlier results

can be found on page 25. 2.8 Prior to sample distribution, a number of randomly selected samples were analysed

for homogeneity and stability. Based on the results of this testing (see Appendix B) it was considered that the samples utilised for this program were homogeneous and stable. As such, any results later identified as outliers could not be attributed to any notable sample variability.

3. Statistical Format

For each test the following information is given:

- 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 with an absolute value less than or equal to 2.0 is considered to be satisfactory, 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 “§”. Laboratories are also encouraged to review results which have an absolute z-score value between 2.0 and 3.0 (i.e. 2.0 < |z-score| < 3.0). These are considered to be questionable results.

Each determination was examined for outliers with all methods pooled. The table on

page 25 summarises the outlier results detected. 3.2 Results Tables and Summary Statistics The tables in Appendix A contain the results returned by each laboratory, including

the code number for the method used and 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.

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A list of summary statistics appears at the bottom of each of the results tables and consists of:

- No. of Results: the total number of results for that test/sample;

- Median: the middle value of the results;

- Normalised IQR: the normalised interquartile range of the results;

- Uncertainty of the Median: a robust estimate of the standard deviation of the Median;

- Robust CV: the robust coefficient of variation expressed as a percentage, i.e. 100 x Normalised IQR / Median;

- Minimum: the lowest laboratory result;

- Maximum: the highest laboratory result; and

- Range: the difference between the Maximum and Minimum.

The median is a measure of the centre of the data. The normalised IQR is a measure of the spread of the results. It is calculated by multiplying the interquartile range (IQR) by a correction factor, which converts the IQR to an estimate of the standard deviation. The IQR is the difference between the upper and lower quartiles (i.e. the values above and below which a quarter of the results lie, respectively). For normally distributed data, the uncertainty of the median is approximated by:

��2 ��

√�

� = number of results. Please see reference [1] for further details on these robust summary statistics.

3.3 Ordered Z-score Charts The charts in Appendix A indicate each laboratory's robust z-score, in order of

magnitude, marked with its laboratory code number. From these charts, each laboratory can readily compare its performance relative to the other laboratories.

These charts contain solid lines at +3.0 and -3.0, 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.

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4. PTA and Technical Adviser’s Comments 4.1 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. Sample preparation was undertaken according to Global Proficiency Ltd’s Standard Operating Procedures to ensure samples were fit-for-purpose, homogeneous and stable. Solutions were stable and homogeneous, and medians obtained from this proficiency round were in consistent agreement with the expected levels (dope concentration), as shown in Table 1. Samples PTA 1 and PTA 2 were prepared from Ammonium Chloride, Sulphanilamide and Potassium Dihydrogen Orthophosphate in distilled water. Sample PTA 3 was prepared from Nicotinic Acid and Tetra Potassium Pyrophosphate in distilled water. All samples were preserved with Sulphuric Acid. The sample format was designed so that two samples had unbound target analyte, with a more challenging third sample which had organically bound analyte, requiring rigorous digestion prior to being analysed. This was intended to provide more realistic and demanding samples for analysis while maintaining homogeneity and stability, continuity with previous rounds, and challenging the ability to troubleshoot any problems. As the assigned value for each analyte in this program is the median of the results submitted by the participants, the uncertainty of the median for each analyte has been calculated and is presented in Table 1 below together with the average analyte recovery data. Table 1. Comparison of expected levels (dope concentration) and proficiency medians. The values of the calculated uncertainty of the median are also presented.

Analyte Sample Dope

Concentration (mg/L)

Median (mg/L)

Analyte Recovery

(%)

Uncertainty of the median

(mg/L)

Total Kjeldahl Nitrogen

PTA 1 7.5 7.070 94.3% 0.117 [1.7%]

PTA 2 35 33.90 96.9% 0.48 [1.4%]

PTA 3 15 14.30 95.3% 0.31 [2.2%]

Total Phosphorus

PTA 1 5 4.990 99.8% 0.039 [0.8%]

PTA 2 1.3 1.240 95.4% 0.018 [1.5%]

PTA 3 7 7.510 107.3% 0.073 [1.0%]

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Average Total Kjeldahl Nitrogen (TKN) recoveries were comparable to those published in APHA 4500 – Norg B (Macro-Kjeldahl Method), which ranged between 87.7-101% recovery of Nicotinic Acid in the concentration range 5-20 mg/L. APHA 4500 – Norg D (Block Digestion and Flow Injection Analysis) predicted Nitrogen recoveries between 81%-134% for spiked natural samples. Total Phosphorus recoveries were also similar to those published in APHA (90.2-108.9%).

4.2 Analysis of Round 186 Results

4.2.1 Total Kjeldahl Nitrogen (TKN) Table 2 compares the TKN medians and robust CVs from this round to those obtained in previous PTA rounds, and in many cases laboratories performed better than previously observed. These CV were however, a little higher than those published in APHA 4500 – Norg B (Macro-Kjeldahl Method), where relative standard deviations (RSD) were between 0.84%-3.46% for concentration ranges of 5-20 mg/L. This published precision data was based on repeatability of various analysts, rather than true reproducibility between different laboratories, where a much larger RSD would be expected. APHA 4500 – Norg D (Block Digestion and Flow Injection Analysis) published RSD of between 3.3%-7.3%, which were closer to CVs observed in this round. Table 2. Comparison of current round variability and proficiency medians of TKN testing with the results of the previous two rounds.

Round Sample Median (mg/L) Robust CV (%) No. of Res ults

This study

PTA 1 7.070 6.2 22

PTA 2 33.90 5.6 24

PTA 3 14.30 8.3 23

Report 815

PTA 1 8.235 5.2 28

PTA 2 25.50 7.8 28

PTA 3 11.40 13.9 27

Report 725

Sample 1 10.60 12.4 35

Sample 2 12.90 5.7 35

Sample 3 12.30 11.8 35

Only a slight increase in CV was observed for the more challenging sample PTA 3 (8.3%) when compared to the more easily digestible samples PTA 1 and PTA 2 (6.2% and 5.6%, respectively). This is a marked improvement over previous rounds. Bias / Accuracy

TKN testing was successfully performed, with satisfactory results (|z-scores| ≤ 2.0) ranging between 6.20 – 7.94 mg/L for sample PTA 1, 30.12 – 37.68 mg/L for sample PTA 2 and 11.93 – 16.67 mg/L for sample PTA 3. Out of 22 participants for sample PTA 1, 24 participants for sample PTA 2 and 23 participants for sample PTA 3, two questionable results (2.0 < |z-scores| < 3.0) were

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obtained for each sample (PTA 1 - laboratories 143 and 185, PTA 2 - laboratories 143 and 633, PTA 3 - laboratories 269 and 556). Four outlier results (|z-scores| ≥ 3.0) were obtained for sample PTA 1 requiring follow-up action by laboratories 150, 269, 480 and 514. Three outlier results were obtained for sample PTA 2, requiring follow-up action by laboratories 150, 514 and 646b. Five outlier results were obtained for sample PTA 3, requiring follow-up action by laboratories 150, 185, 242, 508 and 587.

Laboratory 150 appears to have a systematic error in their TKN method as the reported results for all three samples were consistently below the median, indicating a negative bias.

The TKN dataset formed a normal distribution with no significant bias attributable to any digestion / analysis method (Figures 1 to 3). The most frequently used method to determine TKN was APHA 4500 – Norg B (Macro-Kjeldahl Method), which was used by approximately 36% of participants. Method APHA 4500 – Norg D (Block Digestion and Flow Injection Analysis) was the second most frequently applied digestion / analysis method, used by approximately 22% of participants. Calculation methods were used by approximately 29% of participants.

Figure 1. Spread of results for TKN testing of sample PTA 1, with a median concentration of 7.070 mg/L.

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Results (mg/L)

Total Kjeldahl Nitrogen - Sample PTA 1

APHA 4500 – Norg B.

APHA 4500 – Norg D.

ISO 5663–1984

Discrete Analyser

Calculation

Other

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ISO 5663–1984

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ISO 5663–1984

Discrete Analyser

Calculation

Other

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Catalyst

A large number of participants in this round (approximately 45%) used the Copper catalyst in the digestion of TKN, with a modest number of laboratories reporting Persulphate, Selenium or other catalysts. One participant indicated the use of digestion procedures instead of a catalyst while five participants did not state any catalyst or digestion. Figures 4 to 6 show the distribution of results based on the catalyst used, with no obvious trend in results.

Figure 4. Spread of results for TKN testing of sample PTA 1, based on catalyst.

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Results (mg/L)

Total Kjeldahl Nitrogen Catalyst - Sample PTA 1

Mercury

Copper

Selenium

Persulphate digestion

Other

None Stated

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Mercury

Copper

Selenium


Other

None stated

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Mercury

Copper

Selenium


Other

None stated

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Final Ammonia Method

The most frequently used final Ammonia method in this round was the titrimetric method (APHA 4500 – NH3 C), which was used by approximately 29% of participants. The remaining laboratories used Flow Injection Analysis (APHA 4500 – NH3 H), modified standard methods, discrete analyser and salicylate continuous flow analysis (CFA). A relatively large number of laboratories (approximately 54%) did not report the final Ammonia method. This could be at least in part attributed to the sample analysis procedures being included with the digestion procedures in some methods. Figures 7 to 9 show the distribution of overall TKN results based on the Ammonia analysis method.

Figure 7. Spread of results for TKN testing of sample PTA 1, based on final Ammonia method.

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Results (mg/L)

Total Kjeldahl Nitrogen Final Ammonia Method - Sampl e PTA 1

APHA 4500 – NH₃ C.

APHA 4500 – NH₃ H.

Modified StandardMethod

Discrete Analyser

Salicilate CFA

None stated

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APHA 4500 – NH₃ C.

APHA 4500 – NH₃ H.


Discrete Analyser

Salicilate CFA

None stated

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Results (mg/L)


APHA 4500 – NH₃ C.

APHA 4500 – NH₃ H.


Discrete Analyser

Salicilate CFA

None stated

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Measurement Uncertainty (MU) The MU reported by participants can be seen in Figures 10 to 12. On average, approximately 80% of participants submitted MU information. Most of the stated MUs accurately reflect the difference between the median and the participant’s result for these proficiency samples. Nine laboratories submitted MU results that did not encompass the assigned true value (median) at least for one of the samples tested. A t-test of all the results (outliers removed), indicated that the overall reproducibility for TKN testing in this round was 7.070 ± 0.932 mg/L (13.2%) for sample PTA 1, 33.90 ± 3.67 mg/L (10.8%) for sample PTA 2 and 14.30 ± 2.51 mg/L (17.6%) for sample PTA 3.

Figure 10. MU for TKN testing of sample PTA 1, as reported by participants, compared with 95% confidence interval for overall reproducibility, ± 0.932 mg/L in this round, shown as a dashed line.

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Measurement Uncertainty (mg/L)

Total Kjeldahl Nitrogen ± MU - Sample PTA 1



ISO 5663–1984

Discrete Analyser

Calculation

Other

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Discrete Analyser

Calculation

Other

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Figures 13 to 15 below present the results of TKN testing and the reported MU, compared to the median. The uncertainty of the median was also presented as the dotted line either side of the median.

Figure 13. TKN - Results of sample PTA 1, including MU, compared to the median.

Figure 14. TKN - Results of sample PTA 2, including MU, compared to the median.

4.00

5.00

6.00

7.00

8.00

9.00

10.00

135

143

185

269

322

350

422

480

514

556

567

587

633

646a

646b 648

660

676

Res

ults

(mg/

L)

Laboratory Code


Result ± MU Median Uncertainty of the Median

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(mg/

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Laboratory Code



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Figure 15. TKN - Results of sample PTA 3, including MU, compared to the median. As shown in Figures 13 to 15, laboratories 185, 269, 322, 480, 514, 556, 587, 633 and 646b were further from the assigned value than was encompassed by their MU for at least one of their results, and are recommended to re-examine their quality control procedures (APHA 1020 and 4020 B), MU calculations, or both. Based on the most difficult to analyse samples (PTA 3), laboratory MU would be expected to be somewhere between 4.3% and 24.9% for TKN testing. Of lesser concern, laboratory 135 submitted a MU for sample PTA 3 that was smaller than the uncertainty of the assigned value. If they find that their results are further from the median than their MU encompasses, on successive proficiency rounds, they may wish to re-examine their measurement uncertainty. On the whole, laboratories have a very good understanding of their TKN measurement uncertainty, and are submitting realistic MU values.

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Res

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(mg/

L)

Laboratory Code



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4.2.2 Total Phosphorus Table 3 compares the Total Phosphorus medians and robust CVs from this round to those obtained in previous PTA rounds. Table 3. Comparison of current round variability and proficiency medians of Total Phosphorus testing with the results of the previous two rounds.

Round Sample Median (mg/L) Robust CV (%) No. of Res ults

This study

PTA 1 4.990 3.5 32

PTA 2 1.240 6.9 34

PTA 3 7.510 4.4 32

Report 815

PTA 1 4.250 5.4 33

PTA 2 1.110 6.3 34

PTA 3 2.305 9.5 34

Report 725

Sample 1 1.490 9.0 42

Sample 2 1.200 6.8 42

Sample 3 1.950 8.3 42

Bias / Accuracy Total Phosphorus testing was successfully performed, with satisfactory results (|z-scores| ≤ 2.0) ranging between 4.64 – 5.34 mg/L for sample PTA 1, 1.07 – 1.41 mg/L for sample PTA 2 and 6.85 – 8.17 for sample PTA 3. Out of 32 participants for sample PTA 1, four questionable results (2.0 < |z-scores| < 3.0) were obtained (laboratories 143, 408, 508 and 646b). Out of 34 participants for sample PTA 2, three questionable results were obtained (laboratories 143, 263 and 325). Out of 32 participants for sample PTA 3, four questionable results were obtained (laboratories 143, 160, 408 and 508). Six outlier results (|z-scores| ≥ 3.0) were obtained for sample PTA 1 requiring follow-up action by laboratories 150, 215, 263, 269, 322 and 376. Four outlier results were obtained for sample PTA 2, requiring follow-up action by laboratories 150, 213, 376 and 646b. Three outlier results were obtained for sample PTA 3, requiring follow-up action by laboratories 150, 215 and 269. Laboratory 150 may have made a dilution error when preparing their samples as their results are consistently below the median. The Total Phosphorus dataset formed a normal distribution with no significant bias attributable to any one analysis method (Figures 16 to 18). There was a large variety of methods used for Total Phosphorus analysis in this round, including: Vanado-molybdophosphoric Acid Colorimetric, Stannous Chloride, Ascorbic Acid, FIA, Persulfate, Ammonium Molybdate, Discrete Analyser, HACH test kits, etc.

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Figure 16. Spread of results for Total Phosphorus testing of sample PTA 1, with a median concentration of 4.990 mg/L.


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Total Phosphorus - Sample PTA 1

APHA 4500 – P C.

APHA 4500 – P D.

APHA 4500 – P E.

APHA 4500 – P F.

APHA 4500 – P G.

APHA 4500 – P H.

APHA 4500 – P J.

EN ISO 6878–2004

Modified Standard Method

Discrete Analyser

Test Kit, Colorimeter

Other

Not specified

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Results (mg/L)


APHA 4500 – P C.

APHA 4500 – P D.

APHA 4500 – P E.

APHA 4500 – P F.

APHA 4500 – P G.

APHA 4500 – P H.

APHA 4500 – P J.

EN ISO 6878–2004


Discrete Analyser


Other

Not specified

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Results (mg/L)


APHA 4500 – P C.

APHA 4500 – P D.

APHA 4500 – P E.

APHA 4500 – P F.

APHA 4500 – P G.

APHA 4500 – P H.

APHA 4500 – P J.

EN ISO 6878–2004


Discrete Analyser


Other

Not specified

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Digestion Method

The most frequently used digestion method to determine Total Phosphorus was the APHA 4500 – P B5 (Persulfate Method), which was used by approximately 41% of participants. Figures 19 to 21 show the distribution of results based on the digestion method used, with no obvious trend in results.

Figure 19. Spread of results for Total Phosphorus testing of sample PTA 1, based on digestion method.

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Results (mg/L)

Total Phosphorus Digestion Method - Sample PTA 1

APHA 4500 – P B3.

APHA 4500 – P B4.

APHA 4500 – P B5.

US EPA 200.2

In-house method

Other

Copper

None stated

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Results (mg/L)


APHA 4500 – P B3.

APHA 4500 – P B4.

APHA 4500 – P B5.

US EPA 200.2

In-house method

Other

Copper

None stated

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Results (mg/L)


APHA 4500 – P B3.

APHA 4500 – P B4.

APHA 4500 – P B5.

US EPA 200.2

In-house method

Other

Copper

None stated

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SD 9.17.10

Measurement Uncertainty (MU) The MU reported by participants can be seen in Figures 22 to 24. On average, approximately 80% of participants submitted MU information. Most of the stated MUs accurately reflect the difference between the median and the participant’s result for these proficiency samples. Nine laboratories submitted MU results that did not encompass the assigned true value (median) for at least one of the samples tested. A t-test of all the results (outliers removed), indicated that the overall reproducibility for Total Phosphorus testing in this round was 4.990 ± 0.450 mg/L (9.0%) for sample PTA 1, sample PTA 2 was 1.240 ± 0.200 mg/L (16.1%) and 7.510 ± 0.825 mg/L (11.0%) for sample PTA 3.

Figure 22. MU for Total Phosphorus testing of sample PTA 1, as reported by participants, compared with 95% confidence interval for overall reproducibility, ± 0.450 mg/L in this round, shown as a dashed line.

0

1

2

3

4

5

6

7

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 1.1 1.2 1.3

Fre

quen

cy


Total Phosphorus ± MU - Sample PTA 1

APHA 4500 – P C.

APHA 4500 – P D.

APHA 4500 – P E.

APHA 4500 – P F.

APHA 4500 – P G.

APHA 4500 – P H.

APHA 4500 – P J.

EN ISO 6878–2004


Discrete Analyser


Other

22

SD 9.17.10



0

1

2

3

4

5

6

7

8

9

0 0.03 0.06 0.09 0.12 0.15 0.18 0.21 0.24 0.27 0.3 0.33 0.36 0.39

Fre

quen

cy



APHA 4500 – P C.

APHA 4500 – P D.

APHA 4500 – P E.

APHA 4500 – P F.

APHA 4500 – P G.

APHA 4500 – P H.

APHA 4500 – P J.

EN ISO 6878–2004


Discrete Analyser


Other

0

1

2

3

4

5

6

7

0 0.15 0.3 0.45 0.6 0.75 0.9 1.05 1.2 1.35 1.5 1.65 1.8 1.95

Fre

quen

cy



APHA 4500 – P C.

APHA 4500 – P D.

APHA 4500 – P E.

APHA 4500 – P F.

APHA 4500 – P G.

APHA 4500 – P H.

APHA 4500 – P J.

EN ISO 6878–2004


Discrete Analyser


Other

23

SD 9.17.10

Figures 25 to 27 below present the results of Total Phosphorus testing and the reported MU, compared to the median. The uncertainty of the median was also presented as the dotted line either side of the median.

Figure 25. Total Phosphorus - Results of sample PTA 1, including MU, compared to the median. The outlier result of laboratory 269 is not shown.

Figure 26. Total Phosphorus - Results of sample PTA 2, including MU, compared to the median.

3.5

4

4.5

5

5.5

6

6.5

135

143

185

209

213

322

350

408

422

449

456

480

508

514

556

567

587

598

622

633

646a

646b 648

660

676

Res

ults

(mg/

L)

Laboratory Code



0.8

1

1.2

1.4

1.6

1.8

135

143

185

209

213

242

269

322

350

408

422

449

456

480

508

514

556

567

587

598

622

633

646a

646b 648

660

676

Res

ults

(mg/

L)

Laboratory Code



24

SD 9.17.10

Figure 27. Total Phosphorus - Results of sample PTA 3, including MU, compared to the median. The outlier result of laboratory 269 is not shown. As shown in Figures 25 to 27, laboratories 143, 213, 242, 322, 449, 508, 646b and 676 were further from the assigned value than was encompassed by their measurement uncertainty for at least one of their results and are recommended to re-examine their MU calculations. Based on the sample with the largest CV (PTA 2), laboratory MU would be expected to be somewhere between 3.0% and 20.6% for Total Phosphorus testing. On the whole, the remainder of laboratories have a very good understanding of their Total Phosphorus measurement uncertainty and are submitting realistic MU values.

4.3 Analysis of Results by Method Groups

In order for methods to be grouped for analysis, PTA requires at least 11 sets of results from the same method group. As there were less than 11 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.

5.5

6

6.5

7

7.5

8

8.5

9

9.5

135

143

185

209

213

322

350

408

422

449

456

480

508

514

556

567

587

598

633

646a

646b 648

660

676

Res

ults

(mg/

L)

Laboratory Code



25

SD 9.17.10

5. Outlier Results Laboratories reporting results that have been identified as outliers are listed in Table 4 below.

Table 4. Laboratory results identified as outliers for each analysis performed.

Lab Code

Analysis

Total Kjeldahl Nitrogen Total Phosphorus

PTA 1 PTA 2 PTA 3 PTA 1 PTA 2 PTA 3

150 § § § § § §

185 §

213 §

215 § §

242 §

263 §

269 § § §

322 §

376 § §

480 §

508 §

514 § §

587 §

646b § §

Note: 1. A “§” indicates the occurrence of a z-score outlier result (i.e. those results for which

|z-score| ≥ 3.0).

6. References

[1] Guide to Proficiency Testing Australia, 2014 (This document can be found on the PTA website, www.pta.asn.au)

[2] APHA Standard Methods For the Examination of Water and Wastewater, 2012. 22nd Edition by APHA, AWWA, WEF. American Public Health Association, Washington DC, USA.

SD 9.17.10

APPENDIX A

Results and Data Analysis Total Kjeldahl Nitrogen .......................................................................................................... A1

Total Phosphorus .................................................................................................................. A7

SD 9.17.10

Total Kjeldahl Nitrogen Results

Samples PTA 1, PTA 2 and PTA 3

A1

SD 9.17.10

Total Kjeldahl Nitrogen (TKN)

Results by Laboratory Code

Sample PTA 1

Lab Code Result ± MU1

(mg/L) Robust z-score2

Method Code3

Catalyst Code3

Final Ammonia Method Code3

135 6.90 ± 0.7 -0.39 26 40 # 143 8.1 ± 1.3 2.35 38 40 56 150 3.08 # -9.08 § 26 40 # 160 7.22 # 0.34 24 40 45 185 8.02 ± 0.9 2.16 24 40 45 263 7.30 # 0.52 24 41 45 269 5.558 ± 0.555 -3.44 § 30 41 # 322 7.18 ± 0.1 0.25 37 # # 350 7.38 ± 1.62 0.71 37 # # 422 6.83 ± 0.68 -0.55 37 44 # 480 8.43 ± 1.01 3.10 § 26 39 # 508 6.96 # -0.25 26 39 53 514 5.38 ± 0.382 -3.85 § 34 40 # 556 7.05 ± 0.3 -0.05 24 40 45 567 7.52 ± 0.52 1.02 24 40 52 587 7.48 ± 0.82 0.93 37 44 # 633 7.46 ± 0.37 0.89 24 44 45 646a 7.07 ± 1.2 0.00 24 40 45 646b 6.58 ± 0.66 -1.12 37 # # 648 7.03 ± 1.76 -0.09 26 # 50 660 6.31 ± 0.97 -1.73 24 40 45 676 7.07 ± 1.0 0.00 37 # # No of Results: 22

Median: 7.070

Normalised IQR: 0.439

Uncertainty of the Median:

0.117

Robust CV: 6.2%

Minimum: 3.08

Maximum: 8.43

Range: 5.35

1 Where reported, results are shown with their corresponding measurement uncertainty (MU). 2 "§" denotes an outlier (i.e. those results for which |z-score| ≥ 3.0). Robust z-scores are

calculated as: z = (A - median) ÷ normalised IQR, where A is the participant laboratory's result.

3 Please refer to Appendix C (pages C3-C5) for method, catalyst and final Ammonia method code descriptions.

SD 9.17.10

Total Kjeldahl Nitrogen (TKN)- Sample PTA 1 - Robus t Z-Scores

Ordered R

obust Z-S

core Chart

Total K

jeldahl Nitrogen (T

KN

)- Sam

ple PT

A 1

A2

150

514 26

9

660 64

6b 422

135

508

648

556

646a

676

322

160

263

350

633

587

567

185

143 48

0

-5

-4

-3

-2

-1

0

1

2

3

4

5

z-sc

ore

lab code

A3

SD 9.17.10



Sample PTA 2



Method Code3

Catalyst Code3


135 32.4 ± 3.5 -0.79 26 40 # 143 38 ± 6.5 2.17 38 40 56 150 15.6 # -9.68 § 26 40 # 160 33.1 # -0.42 24 40 45 185 34.4 ± 3.7 0.26 24 40 45 242 34.0 # 0.05 24 40 # 263 35.0 # 0.58 24 41 45 269 33.65 ± 3.365 -0.13 30 41 # 322 35.5 ± 0.1 0.85 37 # # 350 34.5 ± 7.60 0.32 37 # # 422 33.8 ± 3.4 -0.05 37 44 # 480 35.7 ± 4.3 0.95 26 39 # 508 33.3 # -0.32 26 39 53 514 27.6 ± 1.960 -3.33 § 34 40 # 556 34.2 ± 1.4 0.16 24 40 45 567 35.1 ± 2.5 0.63 24 40 52 587 36.5 ± 4.01 1.38 37 44 # 622 31.0 ± 5.2 -1.53 37 # # 633 37.9 ± 1.9 2.12 24 44 45 646a 32.5 ± 5.5 -0.74 24 40 45 646b 24.7 ± 2.5 -4.87 § 37 # # 648 34.8 ± 8.70 0.48 26 # 50 660 32.2 ± 4.96 -0.90 24 40 45 676 33.7 ± 2.0 -0.11 37 # # No of Results: 24

Median: 33.90



0.48

Robust CV: 5.6%

Minimum: 15.6

Maximum: 38

Range: 22.4




SD 9.17.10


Ordered R

obust Z-S

core Chart

Total K

jeldahl Nitrogen (T

KN

)- Sam

ple PT

A 2

A4

150

646b

514

622 66

0

135

646a 16

0

508

269

676

422

242

556

185

350

648

263

567

322

480 58

7 633

143

-5

-4

-3

-2

-1

0

1

2

3

4

5

z-sc

ore

lab code

A5

SD 9.17.10



Sample PTA 3



Method Code3

Catalyst Code3


135 14.2 ± 0.2 -0.08 26 40 # 143 16 ± 2.7 1.43 38 40 56 150 0.5 # -11.63 § 26 40 # 160 14.1 # -0.17 24 40 45 185 6.09 ± 0.9 -6.92 § 24 40 45 242 19.4 # 4.30 § 24 40 # 263 12.8 # -1.26 24 41 45 269 11.567 ± 1.156 -2.30 30 41 # 322 15.6 ± 0.1 1.10 37 # # 350 15.2 ± 3.35 0.76 37 # # 422 14.9 ± 1.5 0.51 37 44 # 480 15.1 ± 1.8 0.67 26 39 # 508 5.88 # -7.10 § 26 39 53 514 13.5 ± 0.959 -0.67 34 40 # 556 16.8 ± 0.7 2.11 24 40 45 567 14.6 ± 1.1 0.25 24 40 52 587 19.5 ± 2.14 4.38 § 37 44 # 622 14.3 ± 2.8 0.00 37 # # 646a 14.1 ± 2.4 -0.17 24 40 45 646b 14.2 ± 1.4 -0.08 37 # # 648 14.8 ± 3.70 0.42 26 # 50 660 13.7 ± 2.1 -0.51 24 40 45 676 15.2 ± 1.0 0.76 37 # # No of Results: 23

Median: 14.30



0.31

Robust CV: 8.3%

Minimum: 0.5

Maximum: 19.5

Range: 19.0




SD 9.17.10


Ordered R

obust Z-S

core Chart

Total K

jeldahl Nitrogen (T

KN

)- Sam

ple PT

A 3

A6

150

508

185

269

263 51

4

660 16

0

646a 13

5

646b

622

567

648

422

480

350

676 32

2 143 55

6

242

587

-5

-4

-3

-2

-1

0

1

2

3

4

5

z-sc

ore

lab code

SD 9.17.10

Total Phosphorus

Samples PTA 1, PTA 2 and PTA 3

A7

SD 9.17.10

Total Phosphorus

Results by Laboratory Code Sample PTA 1



Method Code3

Digestion Code3

135 4.98 ± 0.5 -0.06 5 17

143 4.6 ± 0.27 -2.22 4 19

150 2.13 # -16.24 § 6 40

160 4.94 # -0.28 # #

185 5.13 ± 0.49 0.80 1 19

209 5.01 ± 0.50 0.11 3 19

213 5.11 ± 0.2 0.68 15 19

215 5.54 # 3.12 § 16 #

263 4.20 # -4.49 § 4 18

269 7.873 ± 0.787 16.38 § 11 23

322 5.55 ± 0.01 3.18 § 12 21

350 5.16 ± 0.96 0.97 8 19

376 5.74 # 4.26 § 1 18

408 5.49 ± 0.52 2.84 2 #

422 5.11 ± 0.51 0.68 8 19

449 4.93 ± 0.02 -0.34 16 #

456 4.92 ± 0.18 -0.40 12 21

480 4.91 ± 0.60 -0.45 4 20

508 4.57 ± 0.50 -2.39 6 19

514 4.71 ± 0.391 -1.59 13 19

548 5.0 # 0.06 15 23

556 5.10 ± 0.48 0.62 3 18 1 Where reported, results are shown with their corresponding measurement

uncertainty (MU). 2 "§" denotes an outlier (i.e. those results for which |z-score| ≥ 3.0). Robust z-

scores are calculated as: z = (A - median) ÷ normalised IQR, where A is the participant laboratory's result.

3 Please refer to Appendix C (pages C3-C5) for method and digestion code descriptions.

A8

SD 9.17.10

Total Phosphorus - cont. Results by Laboratory Code

Sample PTA 1



Method Code3

Digestion Code3

567 5.13 ± 0.18 0.80 4 21

587 5.14 ± 1.05 0.85 16 21

598 5.28 ± 0.54 1.65 16 21

622 5.10 ± 0.67 0.62 6 19

633 4.92 ± 0.25 -0.40 16 21

646a 4.85 ± 0.23 -0.80 3 19

646b 4.49 ± 0.45 -2.84 13 19

648 4.96 ± 0.992 -0.17 16 21

660 4.85 ± 0.36 -0.80 2 19

676 4.98 ± 0.10 -0.06 6 19 No of Results: 32

Median: 4.990



0.039

Robust CV: 3.5%

Minimum: 2.13

Maximum: 7.873

Range: 5.743

1 Where reported, results are shown with their corresponding measurement




SD 9.17.10

Total Phosphorus- Sample PTA 1 - Robust Z-Scores

Ordered R

obust Z-S

core Charts

Total P

hosphorus- Sam

ple PT

A 1

A9

Robust Z-Scores

150 26

3

646b 50

8

143 51

4 646a 66

0 480

456

633

449

160

648

135

676

-5

-4

-3

-2

-1

0

1

2

3

4

5z-

scor

e

lab code

-5

-4

-3

-2

-1

0

1

2

3

4

5

z-sc

ore

lab code

A10

SD 9.17.10

Total Phosphorus




Method Code3

Digestion Code3

135 1.25 ± 0.2 0.12 5 17

143 1.0 ± 0.05 -2.82 4 19

150 0.46 # -9.15 § 6 40

160 1.18 # -0.70 # #

185 1.26 ± 0.20 0.23 1 19

209 1.22 ± 0.12 -0.23 3 19

213 1.56 ± 0.1 3.75 § 15 19

215 1.37 # 1.52 16 #

242 1.15 ± 0.05 -1.06 16 19

263 1.04 # -2.35 4 18

269 1.374 ± 0.137 1.57 11 23

322 1.28 ± 0.01 0.47 12 21

325 1.006 # -2.74 16 #

350 1.28 ± 0.24 0.47 8 19

376 2.56 # 15.48 § 1 18

408 1.19 ± 0.11 -0.59 2 #

422 1.31 ± 0.13 0.82 8 19

449 1.22 ± 0.03 -0.23 16 #

456 1.22 ± 0.05 -0.23 12 21

480 1.38 ± 0.17 1.64 4 20

508 1.11 ± 0.12 -1.52 6 19

514 1.24 ± 0.103 0.00 13 19 1 Where reported, results are shown with their corresponding measurement




A11

SD 9.17.10


Sample PTA 2



Method Code3

Digestion Code3

548 1.24 # 0.00 15 23

556 1.31 ± 0.12 0.82 3 18

567 1.23 ± 0.04 -0.12 4 21

587 1.36 ± 0.28 1.41 16 21

598 1.27 ± 0.14 0.35 16 21

622 1.30 ± 0.23 0.70 6 19

633 1.29 ± 0.06 0.59 16 21

646a 1.20 ± 0.06 -0.47 3 19

646b 0.96 ± 0.10 -3.28 § 13 19

648 1.18 ± 0.236 -0.70 16 21

660 1.27 ± 0.12 0.35 2 19

676 1.23 ± 0.05 -0.12 6 19 No of Results: 34

Median: 1.240



0.018

Robust CV: 6.9%

Minimum: 0.46

Maximum: 2.56

Range: 2.10





SD 9.17.10


Ordered R

obust Z-S

core Charts

Total P

hosphorus- Sam

ple PT

A 2

A12

Robust Z-Scores

150

646b 14

3

325 26

3 508 24

2 160

648

408

646a 20

9

449

456

567

676

514

-5

-4

-3

-2

-1

0

1

2

3

4

5z-

scor

e

lab code

-5

-4

-3

-2

-1

0

1

2

3

4

5

z-sc

ore

lab code

A13

SD 9.17.10

Total Phosphorus




Method Code3

Digestion Code3

135 7.51 ± 0.8 0.00 5 17

143 6.6 ± 0.39 -2.74 4 19

150 3.12 # -13.23 § 6 40

160 6.57 # -2.83 # #

185 7.68 ± 1.04 0.51 1 19

209 7.49 ± 0.75 -0.06 3 19

213 7.84 ± 0.3 0.99 15 19

215 8.51 # 3.01 § 16 #

242 7.4 # -0.33 16 19

263 7.50 # -0.03 4 18

269 3.698 ± 0.369 -11.49 § 11 23

322 8.07 ± 0.01 1.69 12 21

350 7.61 ± 1.41 0.30 8 19

376 7.87 # 1.09 1 18

408 8.24 ± 0.79 2.20 2 #

422 7.88 ± 0.79 1.12 8 19

449 7.48 ± 0.11 -0.09 16 #

456 7.60 ± 0.29 0.27 12 21

480 7.20 ± 0.8 -0.93 4 20

508 6.66 ± 0.73 -2.56 6 19

514 7.32 ± 0.608 -0.57 13 19

548 7.30 # -0.63 15 23 1 Where reported, results are shown with their corresponding measurement




A14

SD 9.17.10


Sample PTA 3



Method Code3

Digestion Code3

556 7.62 ± 0.72 0.33 3 18

567 7.74 ± 0.27 0.69 4 21

587 7.80 ± 1.59 0.87 16 21

598 7.95 ± 0.80 1.33 16 21

633 7.51 ± 0.38 0.00 16 21

646a 7.37 ± 0.35 -0.42 3 19

646b 7.05 ± 0.71 -1.39 13 19

648 7.58 ± 1.52 0.21 16 21

660 7.41 ± 0.61 -0.30 2 19

676 7.75 ± 0.10 0.72 6 19 No of Results: 32

Median: 7.510



0.073

Robust CV: 4.4%

Minimum: 3.12

Maximum: 8.51

Range: 5.39





SD 9.17.10


Ordered R

obust Z-S

core Charts

Total P

hosphorus- Sam

ple PT

A 3

A15

Robust Z-Scores

150

269

160

143

508 64

6b 480 54

8

514

646a 24

2

660

449

209

263

135

-5

-4

-3

-2

-1

0

1

2

3

4

5z-

scor

e

lab code

-5

-4

-3

-2

-1

0

1

2

3

4

5

z-sc

ore

lab code

SD 9.17.10

APPENDIX B

Sample Homogeneity and Stability

Homogeneity and Stability Testing ........................................................................................ B1

B1

SD 9.17.10

Homogeneity and Stability Testing Samples for this program were obtained from Global Proficiency Ltd, New Zealand. As such, all samples are subjected to rigorous quality control and homogeneity / stability testing. A random selection of ten samples was chosen from sample sets PTA 1 and PTA 3 for homogeneity and stability testing. Seven of each set were stored frozen, the remaining three were subjected to 35ºC for three days for an accelerated ageing stability trial. The samples were then analysed in duplicate by Hill Laboratories, New Zealand. For sample set PTA 2, two samples were randomly selected, stored frozen in the same conditions as the homogeneity samples and subjected to a verification testing (one replicate per sample) by Hill Laboratories, New Zealand. Homogeneity and stability characteristics were assumed to be similar to samples PTA 1 and PTA 3, based on identical manufacturing procedure and sample handling. All stability samples showed no notable differences when compared to homogeneity samples. Based on the assumption that the rate of ageing doubles with every 7ºC elevated temperature, these samples were assumed stable for more than 96 days (3 days*2(35/7)) from the date of manufacture, for all analytes. From statistical analyses based on the results of this testing and rigorous quality control, it was considered that all samples were sufficiently homogeneous and stable, so that any results later identified as outliers should not be attributed to any notable sample variability. The results of homogeneity and stability testing are presented in Tables B1 to B3 below. Please note that the mean results for these tests are not intended to be used as reference values. Table B1. Homogeneity and stability testing of PTA 1 samples.

Round PTA 186

Samples PTA 1

Sample ID Total Kjeldahl Nitrogen (g/m3) Dissolved Reactive

Phosphorus (g/m3) Duplicate 1 Duplicate 2 Duplicate 1 Duplicate 2

Homogeneity H1 745.7 746.2 500.6 499.2 H2 747.7 745.7 506.2 503.4 H3 763.7 730.9 504.6 506.0 H4 761.7 770.9 502.4 504.2 H5 778.7 759.7 500.0 505.8 H6 781.7 763.7 501.6 506.4 H7 738.2 751.7 505.8 500.0

Stability S1 780.7 759.7 500.2 504.4 S2 745.7 756.7 493.8 503.4 S3 769.2 744.2 502.6 503.4

RSD 2.13% 1.54% 0.71% 0.48%

B2

SD 9.17.10

Table B2. Homogeneity testing of PTA 2 samples.

Round PTA 186

Samples PTA 2



Homogeneity H1 3462.7 128.199 H2 3447.7 128.599

RSD 0.31% 0.22% Table B3. Homogeneity and stability testing of PTA 3 samples.

Round PTA 186

Samples PTA 3



Homogeneity H1 1583.2 1490.9 772.5 767.2 H2 1558.2 1575.4 768.6 762.3 H3 1560.2 1602.9 764.4 746.6 H4 1535.2 1594.4 755.3 753.2 H5 1521.2 1486.4 752.9 753.9 H6 1573.7 1487.9 759.9 750.1 H7 1608.7 1582.9 755.0 745.9

Stability S1 1631.7 1680.4 749.0 750.4 S2 1551.2 1599.9 758.1 760.9 S3 1567.2 1626.9 761.3 769.3

RSD 2.09% 4.14% 0.95% 1.11%

SD 9.17.10

APPENDIX C

Documentation

Instructions to Participants .................................................................................................... C1

Method Codes ....................................................................................................................... C3

Results Sheet ........................................................................................................................ C6

SD 9.17.10

CHEMICAL ANALYSIS ROUND 186 Total Kjeldahl

Please note the following before commencing the analysis of the samples. 1. Samples

i)

ii)

iii)

Please Note:laboratory sample.

2. Sample Preparation

Caution:

i)

ii)

iii)

iv)

v)

vi)

vii)

viii)

Please report results for the diluted sample.

SD 9.17.10

CHEMICAL ANALYSIS ROUND 186


**Please record (on the Results Sheet) the approximate tempe rature

Please note the following before commencing the analysis of the samples.

Samples

Three plastic The bottles contain approximately 22 mL of artificial potable water concentrate for analysis of Total Kjeldahl Nitrogen and Total Phosphorus. The concentrate samples are stabiliseH2SO4, samples PTA 1 and PTA 2 to pH ~2, and sample PTA 3 to pH ~3.

The samples must be thoroughly mixed prior to analysis.

The samples will require dilution in reagent grade waterPreparation

Please Note: laboratory sample.

Sample Preparation

Caution: Analysis must begin immediately after bottle is opened.

Adjust bottle temperature to 20ºC and mix thoroughly to ensure any redissolved prior to dilution step.

Add approximately 900 mL reagent grade water to a one

Record bottle ID number. Open bottle.

Using a volumetric pipette transfer 10.00 mL from the bottle into the flask.

Bring to volume with reagent grade water.

Close with stopper and mix by inversion.

Test according to your normal procedures.

viii) Repeat steps


PROFICIENCY TESTING AUSTRALIA

WATERS PROFICIENCY TESTING PROGRAM


Nitrogen, Total Phosphorus

INSTRUCTIONS TO PARTICIPANTS



Three plastic bottles labelled PTA 1, PTA 2 and PTA 3The bottles contain approximately 22 mL of artificial potable water concentrate for analysis of Total Kjeldahl Nitrogen and Total Phosphorus. The concentrate samples are stabilise

, samples PTA 1 and PTA 2 to pH ~2, and sample PTA 3 to pH ~3.


The samples will require dilution in reagent grade waterPreparation steps below)

Where possible, proficiency testing samples should be treated as a routine laboratory sample.

Sample Preparation

Analysis must begin immediately after bottle is opened.





to volume with reagent grade water.



Repeat steps i) to vii) for the second and third sample.







**Please record (on the Results Sheet) the approximate tempe rature of the samples upon receipt**


bottles labelled PTA 1, PTA 2 and PTA 3The bottles contain approximately 22 mL of artificial potable water concentrate for analysis of Total Kjeldahl Nitrogen and Total Phosphorus. The concentrate samples are stabilise



The samples will require dilution in reagent grade waterbelow).

ere possible, proficiency testing samples should be treated as a routine









for the second and third sample.


C1







bottles labelled PTA 1, PTA 2 and PTA 3The bottles contain approximately 22 mL of artificial potable water concentrate for analysis of Total Kjeldahl Nitrogen and Total Phosphorus. The concentrate samples are stabilise



The samples will require dilution in reagent grade water



Adjust bottle temperature to 20ºC and mix thoroughly to ensure any














bottles labelled PTA 1, PTA 2 and PTA 3, supplied by Global Proficiency Ltd. The bottles contain approximately 22 mL of artificial potable water concentrate for analysis of Total Kjeldahl Nitrogen and Total Phosphorus. The concentrate samples are stabilise



The samples will require dilution in reagent grade water




Add approximately 900 mL reagent grade water to a one-litre volumetric flask.








, supplied by Global Proficiency Ltd. The bottles contain approximately 22 mL of artificial potable water concentrate for analysis of Total Kjeldahl Nitrogen and Total Phosphorus. The concentrate samples are stabilise


The samples will require dilution in reagent grade water (please follow the




litre volumetric flask.


SEPTEMBER, 2015


, supplied by Global Proficiency Ltd. The bottles contain approximately 22 mL of artificial potable water concentrate for analysis of Total Kjeldahl Nitrogen and Total Phosphorus. The concentrate samples are stabilise


(please follow the


Adjust bottle temperature to 20ºC and mix thoroughly to ensure any precipitate has fully

litre volumetric flask.


SEPTEMBER, 2015

, supplied by Global Proficiency Ltd. The bottles contain approximately 22 mL of artificial potable water concentrate for analysis of Total Kjeldahl Nitrogen and Total Phosphorus. The concentrate samples are stabilised with

(please follow the Sample


precipitate has fully

C2

SD 9.17.10

3. Tests Requested

For each of the samples prepared from the three bottles:

i) Total Kjeldahl Nitrogen (TKN)

ii) Total Phosphorus (TP)

(It is recommended that a reagent water blank is analysed by the same method used to analyse the samples.)

If unable to perform the above please note this on your Results Sheet.

4. Safety

i) Samples are for laboratory use only.

ii) Participants should have sufficient experience and training to take the necessary precautions when handling the samples and reagent chemicals and during disposal.

iii) Use of personal protective equipment such as safety glasses, gloves, laboratory coats and fume hoods, where appropriate during the determinations, is recommended

5. Reporting

i) Report results using three significant figures (e.g.: 0.0123, 0.123, 1.23, 12.3).

ii) Report results in milligrams per litre (mg/L).

iii) Do not correct results for recovery.

iv) Select the appropriate method code for each test from the Method Code Table and record it on the Results Sheet.

v) Calculate the measurement uncertainty (MU) for each reported result. All estimates of MU must be given as a 95% confidence interval (coverage factor k ≈ 2) and reported in mg/L. Report MU using the same number of decimal places as for the result.

6. Testing should commence as soon as possible after receiving the samples and results reported

NO LATER THAN 2 OCTOBER 2015 to:

Delfina Mihaila Proficiency Testing Australia PO Box 7507 SILVERWATER NSW 2128 AUSTRALIA Phone: +612 9736 8397 Fax: +612 9743 6664 Email: [email protected]

7. For this program your laboratory has been allocated the code number shown on the attached

Results Sheet. All reference to your laboratory in reports associated with the program will be through this code number, thus ensuring the confidentiality of your results.

8. As a guide, ranges for the samples can be expected to be:

Analyte Range (mg/L) Total Kjeldahl Nitrigen (TKN) 5 - 50 Total Phosphorus (TP) 0.5 - 10

C3

SD 9.17.10

Method Codes to be used for the Results Sheet

ANALYSIS METHOD REFERENCE METHOD DESCRIPTION CODE

Total Phosphorus (TP)

APHA APHA 4500 – P C. Vanadomolybdophosphoric Acid Colorimetric Method 1

APHA 4500 – P D. Stannous Chloride Method 2

APHA 4500 – P E. Ascorbic Acid Method 3

APHA 4500 – P F. Automated Ascorbic Acid Reduction Method 4

APHA 4500 – P G. Flow Injection Analysis for Orthophosphate 5

APHA 4500 – P H. Manual Digestion and Flow Injection Analysis for Total Phosphorus 6

APHA 4500 – P I. In-line UV/Persulfate Digestion and Flow Injection Analysis for Total Phosphorus

7

APHA 4500 – P J. Persulfate Method for Simultaneous Determination of Total Nitrogen and Total Phosphorus

8

USEPA US EPA 0365.1 – 0.365.4 0365.1 Orthophosphate (as P) - Automated Colorimetry 0365.1 Phosphorus, All Forms - Colorimetric/Automated 0365.2 Phosphorus - manual colorimetric/1 reagent 0365.3 Phosphorus - colorimetric/ 2 reagents 0365.4 Phosphorus, Total -Colorimetric/Automated

9

ESS Method 230.1: Total Phosphorus and Total Kjeldahl Nitrogen, Semi-Automated Method

10

ISO / CEN EN ISO 6878:2004 Water Quality - Determination Of Phosphorus - Ammonium Molybdate Spectrometric Method

11

Other Modified Standard Method 12

Discrete Analyser 13

AA / FIA 14

Test Kit, Colorimeter (HACH, Fluka… specify). 15

Other (please specify) 16

Digestion Procedure for TP

APHA APHA 4500 – P B3. Perchloric Acid 17

APHA 4500 – P B4. Sulfuric-Nitric 18

APHA 4500 – P B5. Persulfate 19

USEPA US EPA 0200.2 Phosphorus - Sample Preparation 20

Other In-house method 21

Modified Standard Method 22


C4

SD 9.17.10

Method Codes to be used for the Results Sheet (cont .)



APHA APHA Part 4500 - Norg B. Macro-Kjeldahl Method 24

APHA Part 4500 - Norg C. Semi-Micro Kjeldahl Method 25

APHA Part 4500 - Norg D. Block Digestion and Flow Injection Analysis 26

USEPA USEPA 0351.1 – 0351.4 0351.1 Colorimetric/ Automated 0351.2 Colorimetric 0351.2 Semi-Automated Colorimetric 0351.3 Colorimetric/ Titrimetric 0351.4 Potentiometric

27

ESS Method 230.1: Total Phosphorus and Total Kjeldahl Nitrogen, Semi-Automated Method

28

ASTM ASTM D3590 - 11 Standard Test Methods for Total Kjeldahl Nitrogen in Water 29

ISO / CEN ISO 5663:1984 (EN 25663:1993) Water quality - Determination of Kjeldahl nitrogen - Method after mineralization with selenium

30

ISO 11905-1:1997 Water quality - Determination of nitrogen - Part 1: Method using oxidative digestion with peroxodisulfate

31

EN 12260:2003 Water quality - Determination of nitrogen -Determination of bound nitrogen (TNb), following oxidation to nitrogen oxides

32



AA / FIA 35

Test Kit, Colorimeter (HACH… specify). 36

Calculation (TN-NOx =TKN) 37


TKN Catalyst Mercury 39

Copper 40

Selenium 41

Sodium nitroferricyanide 42

Titanium 43


Continued on next page for Ammonia analysis methods.

C5

SD 9.17.10

Method Codes to be used for the Results Sheet (cont .)


Ammonia Measurement for TKN

APHA APHA 4500 – NH3 C. Titrimetric Method 45

APHA 4500 – NH3 D. Ammonia-Selective Electrode Method 46

APHA 4500 – NH3 E. Ammonia-Selective Electrode Method Using Known Addition 47

APHA 4500 – NH3 F. Phenate Method 48

APHA 4500 – NH3 G. Automated Phenate Method 49

APHA 4500 – NH3 H. Flow Injection Analysis 50

USEPA US EPA 0351.1 – 0351.4 0351.1 Colorimetric/ Automated 0351.2 Colorimetric 0351.2 Semi-Automated Colorimetric 0351.3 Colorimetric/ Titrimetric 0351.4 Potentiometric

51



AA / FIA 54

Test Kit, Colorimeter (e.g. HACH… specify). 55


Method Reference Key i) APHA SM APHA “Standard Methods for the Examination of Water and Wastewater” (18, 19 20,

21, 22 Edition). (http://www.standardmethods.org/) ii) ASTM Annual Book of ASTM Standards, Vol. 11.01(2004). (http://www.astm.org) iii) CEN European Committee for Standardization. (http://www.cen.eu/cen). iv) ISO International Organization for Standardization. (http://www.iso.org). v) US EPA U.S Environmental Protection Agency.

(http://www.epa.gov/osa/fem/methcollectns.htm), (http://www.epa.gov/greatlakes/lmmb/methods).

SD 9.17.10

Please note:Where possible, proficiency testing samples should be treated as a routine

*Approximate temperature of samples upon receipt:

ANALYSIS

Sample PTA 1 Total Kjeldahl Nitrogen (TKN)Total Phosphorus (TP)



i) For

ii) Report results for the diluted sample.

iii) Report results using three significant figures.iv) Report results in

v) Do not correct results for recovery.

vi) MU* Laboratories Measurement Uncertainty (MU) if known for the result. Please report in mg/L

DATE:

INSTRUCT WATERS PROF TEST PROG 186

SD 9.17.10

Please note: Where possible, proficiency testing samples should be treated as a routine


ANALYSIS

Sample PTA 1 (Bottle diluted x100)

Kjeldahl Nitrogen (TKN)

Phosphorus (TP)



Phosphorus (TP)



Phosphorus (TP)

For each prepared sample only a single result is requested.

Report results for the diluted sample.

Report results using three significant figures.Report results in

Do not correct results for recovery.

MU* Laboratories Measurement Uncertainty (MU) if known for the result. Please report in mg/L, using the same number of decimal places as for the result.

DATE: ______________________

Return results Delfina MihailaProficiency Testing AustraliaPO Box 7507 SILVERWATER NSW 2128 AUSTRALIA


PROFICIENCY



Where possible, proficiency testing samples should be treated as a routine


Result (mg/L)

(Bottle diluted x100)



prepared sample only a single result is requested.


Report results using three significant figures.Report results in milligrams per litre (mg/L).


MU* Laboratories Measurement Uncertainty (MU) if known for the result. Please report in , using the same number of decimal places as for the result.

______________________

Return results NO LATEDelfina Mihaila Proficiency Testing AustraliaPO Box 7507 SILVERWATER NSW 2128 AUSTRALIA


PROFICIENCY



Total Kjeldahl Nitrogen, Total PhosphorusSEPTEMBER, 2015

RESULTS SHEET



Result

±MU*(mg/L)






Report results using three significant figures.milligrams per litre (mg/L).



______________________

NO LATER THAN 2 OCTOBER 2015

Proficiency Testing Australia PO Box 7507 SILVERWATER NSW 2128


C6





RESULTS SHEET(mg/L)



±MU* (mg/L)

METHOD



Report results using three significant figures. milligrams per litre (mg/L).


SIGNATURE:

R THAN 2 OCTOBER 2015

PO Box 7507 Phone:SILVERWATER NSW 2128 Fax:

Email:

TESTING AUSTRALIA




RESULTS SHEET


METHOD CODE



SIGNATURE: _______________________________

R THAN 2 OCTOBER 2015 to:

Phone: +61 2 9736 8397 +61 2 9743 6664

Email: [email protected]

TESTING AUSTRALIA




Where possible, proficiency testing samples should be treated as a routine laboratory sample.

Laboratory Code

DIGESTION

or CATALYST

CODE


_______________________________

+61 2 9736 8397 +61 2 9743 6664 [email protected]

laboratory sample.

Laboratory Code

DIGESTION

CATALYST CODE

FINAL AMMONIA METHOD

CODE

MU* Laboratories Measurement Uncertainty (MU) if known for the result. Please report in

_______________________________

[email protected]

laboratory sample.

FINAL AMMONIA METHOD

CODE

MU* Laboratories Measurement Uncertainty (MU) if known for the result. Please report in

_______________________________

SD 9.17.10

- End of Report -

Documents

Report 938 Waters Chem Round 186 Total Kjeldahl Nitrogen