1. QUOVADIS workshop, October 24, 2007 1 QUOVADIS Project Quality Management Organisation, Validation of standards, Developments and Inquiries for SRF Work Package 6 – Deliverable D6.3 “Ruggedness testing on chemical parameters” Roma, 24 October 2007 Dott. Federico Baglivi (federico.baglivi@cesiricerca.it; fbaglivi@hotmail.com)

2. QUOVADIS workshop, October 24, 2007 2 Objectives Evaluation of robustness of Technical Specifications for chemical parameters, as developed by CEN TC 343 WG5, through ruggedness testing on selected reference materials, in particular: prCEN/TS 15407 (WI 343020) Methods for the determination of carbon (C), hydrogen (H) and nitrogen (N) content prCEN/TS 15408 (WI 343022) Methods for the determination of sulphur (S), chlorine (Cl), fluorine (F) and bromine (Br) prCEN/TS 15410 (WI 343024) Method for the determination of the content of major elements (Al, Ca, Fe, K, Mg, Na, P, Si, Ti) prCEN/TS 15411 (WI 343025) Methods for the determination of the content of trace elements (As, Ba, Be, Cd, Co, Cr, Cu, Hg, Mo, Mn, Ni, Pb, Sb, Se, Tl, V and Zn) prCEN/TS 15412 (WI 343026) Methods for the determination of metallic aluminium

3. QUOVADIS workshop, October 24, 2007 3 Ruggedness testing for main factors influencing the procedures for the determination of chemical parameters Key variables must be selected among the main degrees of freedom of each method For each key variable, conservative conditions should be met; i.e. when the methods “passes” the ruggedness testing in those conditions, it will be actually “robust” in most real life cases. The kind of sample to be assigned to each method should emphasize the influence of the key variable under control Criteria for the selection of sample/variable pairs for the evaluation of ruggedness: Robustness is the ability of a method to give consistent results under controlled variations of key analytical parameters/conditions

4. QUOVADIS workshop, October 24, 2007 Shredded tyre (QR-A) Materials used for Ruggedness and Validation Demolition wood (QR-B) Dried sludge (QR-C) dried waste water sewage sludge,filtercake and coal or lignite residues Dried SBS-1 ® (QR-D) Combustible fraction of municipal solid waste. Paper/plastic Fluff (QR- E) Industrial non hazardous waste like a combination of plastic, cardboard and paper

5. QUOVADIS workshop, October 24, 2007 5 prCEN/TS 15407 Methods for the determination of carbon (C), hydrogen (H) and nitrogen (N) content QR-A Shredded tyres sample3Grain size 5 QR-A shredded tyre sample QR-C dried sludge sample QR-E paper plastic fluff sample 3Composition Flash combustion Total levelsNotesNo of levelsKey variablesMethod Activity performed at VTT 1.complete oxidation of sample (“flash combustion”): organic substance  combustion products 2.Reduction and separation on analytes: Combustion gases  reduction furnace  separated in a chromatographic column 3. Detection by instrumental gas analysis procedures (i.e. thermal conductivity detector (TCD))

6. QUOVADIS workshop, October 24, 2007 6 prCEN/TS 15407 Methods for the determination of carbon (C), hydrogen (H) and nitrogen (N) content For nitrogen, the average values at 0.5 mm tend to be higher than at larger grain sizes suggesting a higher relative recovery. RSD values are generally good, and appear to be higher at 1mm grain size Effect of grain size (QR-A shredded tires - 4 independent replicates) Carbon concentration is shown divided by 10 in order to better compare values at the same scale

7. QUOVADIS workshop, October 24, 2007 7 prCEN/TS 15407 Methods for the determination of carbon (C), hydrogen (H) and nitrogen (N) content The results clearly show that for “difficult” samples such shredded tires, the RSD% values are higher while for the other investigated SRFs the RSD values are lower than 5%. The RSD values are higher for N due to the lower concentration level comparing to C and H. Effect of sample type / matrix on repeatability 1 mm grain size (for sample QR-C only a fine grain size was available due the origin of the sample itself). For CHN analysis on 1 mm grain size is adequate for most cases for the analysis of SRF samples of different origin, even if better results can be obtained in terms of precision by using larger amounts or lower grain size. Shredded tires Paper-plastic fluff Dried sludge

8. QUOVADIS workshop, October 24, 2007 8 prCEN/TS 15408 Methods for the determination of sulphur (S), chlorine (Cl), fluorine (F), bromine (Br) QR-E paper plastic fluff sample3grain size 5 QR-A shredded tyre sample QR-C dried sludge sample QR-E paper plastic fluff sample 3composition Combustion Total levelsNotesNo of levelsKey variablesMethod 1.Oxidation by combustion in a bomb containing oxygen under pressure: Halogenated and sulphur compounds  fluorine, chlorine, bromine and sulphate 2. Adsorption solution 3.Determination by ion chromatography techniques Activity performed at CESI Note: For QR-A (shredded tires): problems in preparation of pellets (breaking during combustion)  modifications to the method for these matrices

9. QUOVADIS workshop, October 24, 2007 9 prCEN/TS 15408 Methods for the determination of sulphur (S), chlorine (Cl), fluorine (F), bromine (Br) Recovery appear to be influenced only for sulfur, while for chlorine no clear statements can be done, because of repeatability issues due to heterogeneity of sample. Repeatability is worse at larger grain size for Br and Cl, while it is similar for S. In the case of F the situation is more difficult to explain, with RSD value decreasing from 0.5 to 1 mm, and increasing from 1 to 1.5 mm grain size. A better repeatability is observed in the case of dried sludge, all RSD value are lower than 5%. This result could due to a fixed finer grain size, but also to a less complex matrix. Effect on repeatability Effect on recovery QR-E: paper-plastic fluff – effects of grain size

10. QUOVADIS workshop, October 24, 2007 prCEN/TS 15408 Methods for the determination of sulphur (S), chlorine (Cl), fluorine (F) and bromine (Br) content ParagraphType Comment (justification for change) Proposed change 1 Scope TeRobustness study shown that the method is not applicable in its current form to samples containing tyre pieces because the prepared pellet tend to break during combustion. An alternative method is proposed in Annex B (informative), that is currently not validated. Add the sentence: this method is not applicable on samples containing rubber because it is not possible to prepare suitable pellets for the combustion; for these cases a possible alternative method is described in Annex B (informative). 9.2 Sample Preparation TeRepeatability for chlorine determination is strongly influenced by particle size After 2 nd paragraph add the sentence: Finer particle size (e.g. 0.5 mm) will make better repeatability of analysis especially for chlorine. 9.3 Bomb combustion TeSame as scope.After 3 rd paragraph add the note: this method is not applicable on samples containing rubber because it is not possible to prepare suitable pellets for the combustion; for these cases a possible alternative method is described in Annex B (informative).

11. QUOVADIS workshop, October 24, 2007 prCEN/TS 15408 Methods for the determination of sulphur (S), chlorine (Cl), fluorine (F) and bromine (Br) content ParagraphType Comment (justification for change) Proposed change Annex B (new) TeRobustness study shown that the method is not applicable in its current form to samples containing tyre pieces because the prepared pellet tend to break during combustion. An alternative method is proposed in Annex B (informative), that is currently not validated. Annex B (informative) – Alternative method for combustion of samples containing tyre pieces. Samples containing tyre pieces show the tendency to break during the combustion phase, so some fragments of the pellet might fall into the absorbing solution and consequently oxidation is not quantitative. Such samples can be oxidized with a modification of the method, that avoids the use of absorbing solution inside the bomb. Instead of applying the method at point 9.3 “Bomb combustion”, proceed as follows: Insert the pellet then fill the bomb with oxygen and set up the system following the operator instructions. After combustion make a slow scrubbing of the gas into an absorbing alkaline solution. Determinate analyte by using the proper method. This alternative method is currently not validated.

12. QUOVADIS workshop, October 24, 2007 12 prCEN/TS 15410 Method for the determination of the content of major elements (Al, Ca, Fe, K, Mg, Na, P, Si, Ti) 5 QR-E paper plastic fluff sample4time of heating Method C (perchloric acid at 190 °C) + ICP-OES/MS QR-E paper plastic fluff sample2grain size 2QR-E paper plastic fluff sample2grain size Method B - Ashing (prCEN/TS 15403) + ASTM D4326 (XRF) 3QR-A shredded tyre sample3grain size Method B - Ashing (prCEN/TS 15403) + EN 13656 + ICP- OES/MS QR-E paper plastic fluff sample3+3grain size QR-E paper plastic fluff sample3+3amount of test portion 8+8 QR-A shredded tyre sample QR-B demolition wood QR-C sample dried sludge sample QR-E paper plastic fluff sample 4+4composition Method A - EN 13656 (aqua regia + HF + boric, microwave) + ICP- OES/MS + Method D - EN 13657 (aqua regia only, microwave) + ICP- OES/MS Total levels Notes No of Levels Key variablesMethod

13. QUOVADIS workshop, October 24, 2007 13 prCEN/TS 15411 Methods for the determination of the content of trace elements (As, Ba, Be, Cd, Co, Cr, Cu, Hg, Mo, Mn, Ni, Pb, Sb, Se, Tl, V and Zn) 5 QR-D MSW sample3amount of test portion Hg direct - AMA QR-D MSW sample3grain size 5 QR-E paper plastic fluff sample4time of heating Method C (perchloric acid at 190 °C) + ICP-OES/MS QR-E paper plastic fluff sample2grain size 3QR-A shredded tyre sample3grain size Method B – Ashing (prCEN/TS 15403) + EN 13656 + ICP-OES/MS QR-E paper plastic fluff sample3+3grain size QR-E paper plastic fluff sample3+3amount of test portion 8+8 QR-A shredded tyre sample QR-B demolition wood QR-C sample dried sludge sample QR-E paper plastic fluff sample 4+4composition Method A - EN 13656 (aqua regia + HF + boric, microwave) + ICP-OES/MS + Method D - EN 13657 (aqua regia only, microwave) + ICP- OES/MS Total levels Notes No of Levels Key variablesMethod

14. QUOVADIS workshop, October 24, 2007 14 prCEN/TS 15410 - prCEN/TS 15411 Method A - EN 13656 (aqua regia-HF-boric, microwave) Activity performed at ENEL No significant influence in recovery. Larger amount of test portion gives generally lower RSD values. Same behavior for minor elements (prTS 15411) Effect of grain size (QR-E – paper-plastic fluff) Effect of amount of test portion (QR-E – Paper plastic fluff) Some influences can be observed for some elements, but they don't appear to be dramatic.

15. QUOVADIS workshop, October 24, 2007 15 prCEN/TS 15410 - prCEN/TS 15411 Method A - EN 13656 (aqua regia-HF-boric, microwave) Method A results to be applicable for each kind of matrix tested; higher values of RSD are explained by intrinsic heterogeneity of samples. Same behavior for minor elements (prTS 15411) Samples: QR-A (shredded tyre), QR-B (demolition wood), QR-C (sludge) and QR-E (paper-plastic fluff) Test portion: 0.2 g Grain size: 1 mm, except QR-C dried sludge (finer).

16. QUOVADIS workshop, October 24, 2007 16 prCEN/TS 15410 - prCEN/TS 15411 Method D - EN 13657 (aqua regia, heating) Activity performed at ENEL Test portion effect is generally not evident in recovery of major and trace elements. RSD values in general are about 4% for QR-E. Same behavior for minor elements (prTS 15411) Higher values of RSD for minor elements (approximately 20%) were explained by their lower concentrations. Effect of grain size (QR-E – paper plastic fluff) Effect of amount of test portion (QR-E – paper plastic fluff) No significant differences are observed in the average values of samples QR-E at different grain size levels, RSD average value is 3 %.

17. QUOVADIS workshop, October 24, 2007 17 prCEN/TS 15410 - prCEN/TS 15411 Method D - EN 13657 (aqua regia, heating) Method D results to be applicable for each kind of matrix tested; higher values of RSD are explained by intrinsic heterogeneity of samples. Same behavior for minor elements (prTS 15411) Samples: QR-A (shredded tyre), QR-B (demolition wood), QR-C (dried sludge) and QR-E (paper-plastic fluff) Test portion: 0.2 g Grain size: 1 mm, except QR-C sludge (finer).

18. QUOVADIS workshop, October 24, 2007 18 prCEN/TS 15410 - prCEN/TS 15411 Method A - EN 13656 (aqua regia-HF-boric, microwave) Method D - EN 13657 (aqua regia,heating) Activity performed at ENEL Ratio of recovery between EN 13657 and EN 13656 (aqua regia vs “total” HF) Recovery rate isn’t significantly different between the two digestion procedures for almost all elements, except for Si, Ti and Sb (and Al in sewage sludge QR-C only). Note: recovery of Si with EN 13656 is not guaranteed because of volatility of SiF 4.

19. QUOVADIS workshop, October 24, 2007 19 prCEN/TS 15410 - prCEN/TS 15411 Method B - Ashing (prCEN/TS 15403) + EN 13656 (HF, HNO3, HCl) Significant, not dramatic, influence of grain size for many elements (Fe, Ca, Al, K, Mg, P and minor elements). This behaviour was expected for this kind of matrix (oxides, refractory). Note: recovery of Si with EN 13656 is not guaranteed because of volatility of SiF 4 Effect of grain size (QR-A – shredded tires) Activity performed at ENEL

20. QUOVADIS workshop, October 24, 2007 20 prCEN/TS 15410 Method B - Ashing (prCEN/TS 15403) + ASTM D4326 (XRF) Activity performed at CESI – APAT – ENEL Grinded ash shows generally lower RSD%. The average concentration values for the major and minor elements are similar for grinded and non grinded ash, thus showing that the ash is sufficiently fine to be analysed as such by XRF. Differences are observed between XRF results from the three labs even if calibrants and samples were prepared in same lab; this might be due to the different technologies of the instruments used. Furthermore, it appears that there is no “best” XRF technology for this kind of application. ED-XRFLab 3 EDP-XRFLab 2 WD-XRFLab 1

21. QUOVADIS workshop, October 24, 2007 21 prCEN/TS 15410 - prCEN/TS 15411 Method C (perchloric acid at 190 °C) The results obtained in this work show that: 10 hours heating time is generally sufficient for major and minor element recovery from paper/plastic SRF sample; but for some elements (Ti, Ba, Ca, Mg, K, Al) this is not true, a longer digestion time is required; Mg, Ba, Ca, Ti and P show also a significant interbottle difference It seems that generally RSD values are better at 0.5 mm in comparison to 1 mm grain size, but this is not so evident Differences are observed for the average values at 0.5 and 1 mm grain size: these differences are larger at 10 hours heating time, while the results are more similar at 20 hours time of heating This method requires the use of suitable closed bombs in order to stand the high pressure during digestion due to CO2 generation and to liquid vapour pressure of the acid mixture upon heating up to 190 °C. Not all the types of teflon bombs can be used, as clearly demonstrated in this work: stainless steel bombs are seldom used in the laboratories, because of the replacement with microwave digestion systems. Activity performed at VTT/ CESI

22. QUOVADIS workshop, October 24, 2007 22 prCEN/TS 15411 Hg by direct method (AMA – thermal decomposition, spectrometric determination of Hg vapors) Influence of test portion: 50, 75, 100 mg (QR-B – demolition wood, QR-E – paper-plastic fluff) Influence of grain size: 0.5, 1, 1.5 mm (QR-E – paper plastic fluff). No significant difference are observed in the average values of paper plastic samples at different test portion and grain size levels too; the RSD values are good (between 4 and 11%). Demolition woos samples (QR-B) showed RSD values between 13 and 34%; higher RSD values were related to heterogeneity of the sample itself; no influence by amount of test portion in this case as well. Tests performed at APAT

23. QUOVADIS workshop, October 24, 2007 prCEN/TS 15410 Methods for the determination of the content of major elements (Al, Ca, Fe, K, Mg, Na, P, Si, Ti) ParagraphType Comment (justification for change) Proposed change 1 Scope TeIn addition to the digestion procedure already included in the TS, one more validated standard for waste samples is available (EN 13657). This standard implies the use of aqua regia only and for most elements has quite comparable performance to EN 13656 (hydrofluoric acid + aqua regia). Let the user the possibility to avoid the use of HF will make the procedure a bit safer and less problematic for instrumentation and devices. In the first paragraph change “three methods” into “four methods”. Add point d): d) microwave assisted digestion with nitric and hydrochloric acid mixture (aqua regia) In the fifth paragraph change the first sentence from “Method a) is recommended…” into “Methods a) and d) are recommended…” At the end of fifth paragraph add: “method d) is not suitable for determination of Si and Ti because of poor recovery”. Last sentence should be modified as follows: All the listed methods but d) are suitable for the determination of Si, provided that closed containers are used for sample dissolution. XRF is highly recommended for Si, P and Ti analysis. 2 Normative References TeSame as aboveAdd: EN 13657 "Characterization of waste – Digestion for subsequent determination of aqua regia soluble portion of elements"

24. QUOVADIS workshop, October 24, 2007 prCEN/TS 15410 Methods for the determination of the content of major elements (Al, Ca, Fe, K, Mg, Na, P, Si, Ti) ParagraphType Comment (justification for change) Proposed change 9.1 Method A TeDissolution with HF might produce SiF4 (volatile) so a warning must be issued At the end of 9.1 add a note like: Digestion with HF might produce SiF4 that is a volatile compound, so if determination of Si is needed, special care has to be taken in this sense. 9.4 Method D (new) TeIn addition to the digestion procedure already included in the TS, one more validated standard for waste samples is available (EN 13657). This standard implies the use of aqua regia only and for most elements has quite comparable performance to EN 13656 (hydrofluoric acid + aqua regia). Let the user the possibility to avoid the use of HF will make the procedure a bit safer and less problematic for instrumentation and devices. Add: Weigh between 0,2 g to 0,5 g of the sample, to the nearest 0,1 mg, prepared according to Clause 8 and transfer it into the vessel. If necessary the sample may be moistened with a minimum amount of water. Proceed according to the general principle of EN 13657. After cooling the solutions are transferred to volumetric flasks of suitable volume (e.g. 50ml). Any residue shall be separated by filtration or centrifugation and the composition is controlled by XRF: if a significant amount of the elements of interest is detected, an alternative digestion method for the dissolution of the residual material is necessary. 10.3 Note 3 TeInfluence by particle size is not dramatic Delete word “strongly”

25. QUOVADIS workshop, October 24, 2007 prCEN/TS 15411 Methods for the determination of the content of trace elements (As, Ba, Be, Cd, Co, Cr, Cu, Hg, Mo, Mn, Ni, Pb, Sb, Se, Tl, V and Zn) ParagraphType Comment (justification for change) Proposed change 1 Scope TeIn addition to the digestion procedure already included in the TS, one more validated standard for waste samples is available (EN 13657). This standard implies the use of aqua regia only and for most elements has quite comparable performance to EN 13656 (hydrofluoric acid + aqua regia). Let the user the possibility to avoid the use of HF will make the procedure a bit safer and less problematic for instrumentation and devices. In the first paragraph change “three methods” into “four methods”. Add point d): d) microwave assisted digestion with nitric and hydrochloric acid mixture (aqua regia) In the fourth paragraph change the first sentence from “Method a) is recommended…” into “Methods a) and d) are recommended…” At the end of fifth paragraph add: “method d) is not suitable for determination of Sb because of poor recovery”. 2 Normative References TeSame as aboveAdd: EN 13657 "Characterization of waste – Digestion for subsequent determination of aqua regia soluble portion of elements" 5 Principle TeA reference to the direct determination of Hg is missing Add at the end of sentence: “or, when available, dedicated specific methods (Hg)”.

26. QUOVADIS workshop, October 24, 2007 prCEN/TS 15411 Methods for the determination of the content of trace elements (As, Ba, Be, Cd, Co, Cr, Cu, Hg, Mo, Mn, Ni, Pb, Sb, Se, Tl, V and Zn) ParagraphType Comment (justification for change) Proposed change 9.2 Method B TeAshing can lead to loss of volatile elements Add at the end of 9.2 a note like: “high temperature (550 °C) reached during ashing can lead to loss of volatile elements”. 9.4 Method D (new) TeSame as comment for point 1 (Scope) Add: Weigh between 0,2 g to 0,5 g of the sample, to the nearest 0,1 mg, prepared according to Clause 8 and transfer it into the vessel. If necessary the sample may be moistened with a minimum amount of water. Proceed according to the general principle of EN 13657. After cooling the solutions are transferred to volumetric flasks of suitable volume (e.g. 50 ml). Any residue shall be separated by filtration or centrifugation and the composition is controlled by XRF: if a significant amount of the elements of interested is detected, an alternative digestion method for the dissolution of the residual material is necessary.

27. QUOVADIS workshop, October 24, 2007 27 Activity performed at VTT 33grain sizeMethod B - ashing + DTA 3grain size 3amount of test portion 73boiling timeMethod A – Leaching with HNO3, filtering, alkaline digestion of residue, determination of Al by ICP-OES or FAAS. Total levelsNotesNo of levels Key variablesMethod prCEN/TS 15412 Methods for the determination of metallic aluminium

28. QUOVADIS workshop, October 24, 2007 prCEN/TS 15412 Methods for the determination of metallic aluminium (method A) Leaching with HNO3, filtering, alkaline digestion of residue, determination of Al by ICP-OES or FAAS. Metallic particles are heterogeneously distributed in the sample  large test portions are to be used (i.e. up to 5 g test portion if metallic aluminium is not visible in the sample). Due to high particle density variation in samples and test portions attention should be paid on possible segregation of particle during transportation, handling and even when removing a test portion from laboratory sample. Recovery rate can be checked by spiking with metallic aluminium.

29. QUOVADIS workshop, October 24, 2007 prCEN/TS 15412 Method for the determination of metallic aluminium (method B – ashing + DTA) The main interference in the measurement was found to be is calcite in the samples. If calcite content and aluminium content on the sample are high or low, the determination of metallic aluminium goes without problems. If the concentration of another component is high and the concentration of the other component is low, it seems better to make ashes at 815 ºC and aluminium content is determined immediately. Ashing of samples was made at 550  C and 800  C, because calcium carbonate doesn’t degrade at 550°C. Sample: paper plastic fluff (QR-E)

30. QUOVADIS workshop, October 24, 2007 prCEN/TS 15412 Methods for the determination of metallic aluminium ParagraphType Comment (justification for change) Proposed change 9.2 Sample preparation TeHomogeneity for this parameter is critical Add: “It is recommended that laboratory samples are homogenised properly before extracting of test portion. This may be done using so called long pile technique.” 11 Quality control TeFor this parameter a recovery control is possible Add: “Recovery rate of the test method is checked using spiked samples, e.g. virgin woody material mixed with known amount of metallic aluminium (of different film thicknesses).”

31. QUOVADIS workshop, October 24, 2007 Some of main results that led to proposals of amendments for methods are listed below: Robustness study shows that the method prCEN/TS 15408 (determination of S, Fl, Cl and Br) is not applicable in its current form to some samples (e.g. containing tyre pieces) because the prepared pellet tend to break during combustion. To overcome this limitation, some amendments to the method have been proposed to CEN TC 343. Method D (digestion with only aqua regia) proposed in addition to the digestion procedure already included in the TS 15410 and 15411, has quite comparable performance to Method A (EN 13656: hydrofluoric acid + aqua regia) for most elements (except for Si, Ti, Sb). All amendments have been discussed and approved by WG5 of TC/343