Transcript QUOVADIS GRANT - Agreement EIE/031/S07.38597

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
([email protected]; [email protected])
QUOVADIS workshop, October 24, 2007
1
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
QUOVADIS workshop, October 24, 2007
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Ruggedness testing for main factors influencing the procedures for the
determination of chemical parameters
Robustness is the ability of a method to give consistent results under
controlled variations of key analytical parameters/conditions
Criteria for the selection of sample/variable pairs for
the evaluation of ruggedness:
•
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
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Materials used for Ruggedness and Validation
Shredded tyre (QR-A)
Demolition wood (QR-B)
Dried SBS-1® (QR-D)
Paper/plastic Fluff (QR- E)
Combustible fraction of
municipal solid waste.
Industrial non hazardous waste like a
combination of plastic, cardboard and
paper
QUOVADIS workshop, October 24, 2007
Dried sludge (QR-C)
dried waste water sewage
sludge,filtercake and coal or
lignite residues
prCEN/TS 15407 Methods for the determination of carbon (C),
hydrogen (H) and nitrogen (N) content
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))
Activity performed at VTT
Method
Flash
combustion
Key variables
Composition
Grain size
No of levels
Notes
3
QR-A shredded tyre sample
QR-C dried sludge sample
QR-E paper plastic fluff sample
3
Total levels
5
QR-A Shredded tyres sample
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prCEN/TS 15407 Methods for the determination of carbon (C),
hydrogen (H) and nitrogen (N) content
Effect of grain size (QR-A shredded tires - 4 independent replicates)
QR-A 0.5mm
8
QR-A 1mm
7
QR-A 1.5mm
conc %
6
For nitrogen, the average values
at 0.5 mm tend to be higher than
at larger grain sizes suggesting a
higher relative recovery.
5
4
3
2
1
0
C/10
H
N
Carbon concentration is shown divided by 10 in order to better compare values at the same scale
RSD values are generally good, and appear to be higher at 1mm grain size
QUOVADIS workshop, October 24, 2007
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prCEN/TS 15407 Methods for the determination of carbon (C),
hydrogen (H) and nitrogen (N) content
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).
QR-A 1mm
14
QR-A2 1mm
QR-E 1mm
12
QR-C
Shredded tires
Shredded tires
Paper-plastic fluff
Dried sludge
RSD %
10
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%.
8
6
4
2
The RSD values are higher for N due to the
lower concentration level comparing to C and H.
0
C
H
N
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.
QUOVADIS workshop, October 24, 2007
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prCEN/TS 15408 Methods for the determination of sulphur (S),
chlorine (Cl), fluorine (F), bromine (Br)
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
Method
Key variables
composition
No of levels
Notes
3
QR-A shredded tyre sample
QR-C dried sludge sample
QR-E paper plastic fluff sample
Combustion
grain size
3
Total levels
5
QR-E paper plastic fluff sample
Note:
For QR-A (shredded tires): problems in preparation of pellets (breaking during combustion)  modifications
to the method for these matrices
QUOVADIS workshop, October 24, 2007
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prCEN/TS 15408 Methods for the determination of sulphur (S),
chlorine (Cl), fluorine (F), bromine (Br)
QR-E: paper-plastic fluff – effects of grain size
Effect on repeatability
Effect on recovery
QR-E 0.5mm
QR-E 1.0mm
QR-E 1.5mm
600
500
20
RSD (%)
400
mg/kg
QR-E (0,5 mm)
QR-E (1,0 mm)
QR-E (1,5 mm)
25
300
15
10
200
5
100
0
0
F
Br
Cl /10
S/10
F
Br
Cl
S
• 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.
QUOVADIS workshop, October 24, 2007
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prCEN/TS 15408
Methods for the determination of sulphur (S), chlorine (Cl), fluorine
(F) and bromine (Br) content
Paragraph
Type
1
Scope
Te
9.2
Sample
Preparation
Te
9.3
Bomb
combustion
Te
Comment
(justification for change)
Robustness 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.
Repeatability for chlorine
determination is strongly
influenced by particle size
Same as scope.
QUOVADIS workshop, October 24, 2007
Proposed change
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).
After 2nd paragraph add the sentence:
Finer particle size (e.g. 0.5 mm) will make
better repeatability of analysis especially
for chlorine.
After 3rd 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).
prCEN/TS 15408
Methods for the determination of sulphur (S), chlorine (Cl), fluorine (F)
and bromine (Br) content
Paragraph
Type
Annex B
(new)
Te
Comment
(justification for change)
Robustness 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.
QUOVADIS workshop, October 24, 2007
Proposed change
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.
prCEN/TS 15410 Method for the determination of the content of major
elements (Al, Ca, Fe, K, Mg, Na, P, Si, Ti)
Method
Method A - EN 13656 (aqua regia
+ HF + boric, microwave) + ICPOES/MS
+
Method D - EN 13657 (aqua
regia only, microwave) + ICPOES/MS
Key variables
composition
No of
Levels
4+4
Notes
Total
levels
QR-A shredded tyre sample
QR-B demolition wood
QR-C sample dried sludge sample
QR-E paper plastic fluff sample
8+8
amount of test portion
3+3
QR-E paper plastic fluff sample
grain size
3+3
QR-E paper plastic fluff sample
Method B - Ashing (prCEN/TS
15403) + EN 13656 + ICPOES/MS
grain size
3
QR-A shredded tyre sample
3
Method B - Ashing (prCEN/TS
15403) + ASTM D4326 (XRF)
grain size
2
QR-E paper plastic fluff sample
2
time of heating
4
QR-E paper plastic fluff sample
grain size
2
QR-E paper plastic fluff sample
Method C (perchloric acid at 190
°C) + ICP-OES/MS
5
QUOVADIS workshop, October 24, 2007
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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)
Method
Method A - EN 13656 (aqua
regia + HF + boric,
microwave) + ICP-OES/MS
+
Method D - EN 13657 (aqua
regia only, microwave) + ICPOES/MS
Method B – Ashing
(prCEN/TS 15403) + EN
13656 + ICP-OES/MS
Key variables
composition
No of
Levels
Notes
4+4
QR-A shredded tyre sample
QR-B demolition wood
QR-C sample dried sludge sample
QR-E paper plastic fluff sample
amount of test portion
3+3
QR-E paper plastic fluff sample
grain size
3+3
QR-E paper plastic fluff sample
grain size
3
QR-A shredded tyre sample
amount of test portion
3
QR-D MSW sample
grain size
3
QR-D MSW sample
time of heating
4
QR-E paper plastic fluff sample
grain size
2
QR-E paper plastic fluff sample
Total
levels
8+8
3
Hg direct - AMA
Method C (perchloric acid at
190 °C) + ICP-OES/MS
5
5
QUOVADIS workshop, October 24, 2007
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prCEN/TS 15410 - prCEN/TS 15411
Method A - EN 13656 (aqua regia-HF-boric, microwave)
Activity performed at ENEL
QR-E 0.5mm
1
Effect of grain size (QR-E –
paper-plastic fluff)
QR-E 1.5mm
0.8
Conc %
variable:grain size
QR-E 1mm
0.6
Some influences can be observed for some
elements, but they don't appear to be dramatic.
0.4
0.2
0
Al
Ca
Fe
QR-E 0.1g
1
Conc %
0.8
K
Mg
Na
P
Si
Ti
Effect of amount of test portion (QR-E –
Paper plastic fluff)
variable: amount of test portion
QR-E 0.2g
QR-E 0.4g
No significant influence in recovery. Larger amount
of test portion gives generally lower RSD values.
0.6
0.4
0.2
0
Al
Ca
Fe
K
Mg
Na
P
Si
Ti
Same behavior for minor elements (prTS 15411)
QUOVADIS workshop, October 24, 2007
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prCEN/TS 15410 - prCEN/TS 15411
Method A - EN 13656 (aqua regia-HF-boric, microwave)
•
RSD %
•
•
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).
EN 13656
variable: composition
40
35
30
25
20
15
10
5
0
QR-E
QR-A
QR-B
QR-C
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)
Al
Ca
Fe
K
Mg
Na
P
Si
Ti
QUOVADIS workshop, October 24, 2007
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prCEN/TS 15410 - prCEN/TS 15411
Method D - EN 13657 (aqua regia, heating)
Activity performed at ENEL
QR-E (paper- plastic fluff) EN 13657
variable:grain size
1
QR-E 0.5mm
QR-E 1mm
QR-E 1.5mm
Effect of grain size (QR-E –
paper plastic fluff)
0.8
No significant differences are observed in the
average values of samples QR-E at different
grain size levels, RSD average value is 3 %.
%
0.6
0.4
0.2
0
Al
Ca/10
Fe
K
Mg
Na
P
Si
Ti
QR-E 0.1g
QR-E 0.2g
QR-E 0.4g
QR-E (paper- plastic fluff) EN 13657
variable:amount of test portion
Effect of amount of test portion (QR-E –
paper plastic fluff)
1
Test portion effect is generally not evident in recovery
of major and trace elements. RSD values in general
are about 4% for QR-E.
0.8
%
0.6
0.4
Same behavior for minor elements (prTS 15411)
0.2
0
Al
Ca/10
Fe
K
Mg
Na
P
Si
Ti
Higher values of RSD for minor elements
(approximately 20%) were explained by their lower
concentrations.
QUOVADIS workshop, October 24, 2007
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prCEN/TS 15410 - prCEN/TS 15411
Method D - EN 13657 (aqua regia, heating)
•
•
•
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).
EN 13657
variable: composition
QR-E
QR-A
QR-B
QR-C
40
35
30
25
20
15
10
5
0
RSD %
Method D results to be applicable for
each kind of matrix tested; higher values
of RSD are explained by intrinsic
heterogeneity of samples.
Al
Ca
Fe
K
Mg
Na
P
Si
Ti
QUOVADIS workshop, October 24, 2007
Same behavior for minor elements
(prTS 15411)
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prCEN/TS 15410 - prCEN/TS 15411
Method A - EN 13656 (aqua regia-HF-boric, microwave)
Method D - EN 13657 (aqua regia,heating)
QR-A
Ratio mean conc- EN 13657 / EN 13656
Activity performed at ENEL
QR-B
1.8
1.6
1.4
1.2
1
0.8
0.6
0.4
0.2
0
QR-C
QR-E
Al
Ca
Fe
K
Mg
Na
P
Si
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).
Ti
QR-A
QR-B
ratio mean conc EN13657 / EN 13656
1.8
1.6
1.4
1.2
1
0.8
0.6
0.4
0.2
0
QR-C
QR-E
Note: recovery of Si with EN 13656
is not guaranteed because of
volatility of SiF4.
Cr
As
Sb
Pb
Ba
Co
Cu
Mn
Mo
Ni
V
QUOVADIS workshop, October 24, 2007
Zn
18
prCEN/TS 15410 - prCEN/TS 15411
Method B - Ashing (prCEN/TS 15403) + EN 13656 (HF, HNO3, HCl)
Effect of grain size (QR-A – shredded tires)
Activity performed at ENEL
QR-A 0.5mm
0.5
25
QR-A 1mm
QR-A 05
100
QR-A 15
20
80
0.3
15
60
mg/kg
0.2
10
1000
800
mg/kg
0.4
conc %
conc %
1200
QR-A 1
QR-A 1.5mm
600
40
400
5
0.1
20
0
0
Al
Ca
K
Mg
Na
P
Ti
200
0
Si
Fe
0
Cr
As
Cd
Sb
Pb
Ba
Ni
Zn
Co
Cu
Mn
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 SiF4
QUOVADIS workshop, October 24, 2007
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prCEN/TS 15410
Method B - Ashing (prCEN/TS 15403) + ASTM D4326 (XRF)
Activity performed at CESI – APAT – ENEL
Sample E - ash plastic-paper fluff bott 1
35
30
Lab 1
Lab 2
Lab 3
lab 1
lab 2
lab 3
Grinded ash shows generally lower RSD%.
RSD (%)
25
20
15
10
5
0
Na Mg Al Si S
K
C a Ti C r Mn Fe C o Ni C u Zn As Se Sr Ba Pb V
Sample E - grinded ash plastic-paper fluff bott 1
35
Sb Sn Tl P
lab 1
lab 2
lab 3
30
25
RSD (%)
WD-XRF
EDP-XRF
ED-XRF
20
15
10
5
0
Na Mg Al Si S
K
C a Ti C r Mn Fe C o Ni C u Zn As Se Sr Ba Pb V
Sb Sn Tl
P
QUOVADIS workshop, October 24, 2007
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.
20
prCEN/TS 15410 - prCEN/TS 15411
Method C (perchloric acid at 190 °C)
Activity performed at VTT/ CESI
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.
QUOVADIS workshop, October 24, 2007
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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)
.
Tests performed at APAT
QR-E - effect of grain size
70
60
60
50
50
40
40
µg/kg
µg/kg
QR-E - effect of am ount of test portion
70
30
30
20
20
10
10
0
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%).
0
50 mg
75 mg
100 mg
0.5mm
1mm
1.5mm
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.
QUOVADIS workshop, October 24, 2007
22
prCEN/TS 15410
Methods for the determination of the content of major elements
(Al, Ca, Fe, K, Mg, Na, P, Si, Ti)
Paragraph
Type
1
Scope
Te
2
Normative
References
Te
Comment
(justification for change)
In 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.
Same as above
QUOVADIS workshop, October 24, 2007
Proposed change
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.
Add:
EN 13657 "Characterization of waste –
Digestion for subsequent determination of aqua
regia soluble portion of elements"
prCEN/TS 15410
Methods for the determination of the content of major elements
(Al, Ca, Fe, K, Mg, Na, P, Si, Ti)
Paragraph
Type
9.1
Method A
Te
9.4
Method D
(new)
Te
10.3
Note 3
Te
Comment
(justification for change)
Dissolution with HF might
produce SiF4 (volatile) so a
warning must be issued
In 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.
Influence by particle size is
not dramatic
QUOVADIS workshop, October 24, 2007
Proposed change
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.
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.
Delete word “strongly”
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)
Paragraph
Type
1
Scope
Te
2
Normative
References
Te
5
Principle
Te
Comment
(justification for change)
In 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.
Same as above
A reference to the direct
determination of Hg is missing
QUOVADIS workshop, October 24, 2007
Proposed change
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”.
Add:
EN 13657 "Characterization of waste – Digestion
for subsequent determination of aqua regia
soluble portion of elements"
Add at the end of sentence: “or, when available,
dedicated specific methods (Hg)”.
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)
Paragraph
Type
9.2
Method B
Te
9.4
Method D
(new)
Te
Comment
(justification for change)
Ashing can lead to loss of
volatile elements
Same as comment for point 1
(Scope)
QUOVADIS workshop, October 24, 2007
Proposed change
Add at the end of 9.2 a note like: “high
temperature (550 °C) reached during ashing can
lead to loss of volatile elements”.
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.
prCEN/TS 15412
Methods for the determination of metallic aluminium
Activity performed at VTT
Method
Key variables
No of
levels
Method A – Leaching with HNO3,
filtering, alkaline digestion of residue,
determination of Al by ICP-OES or FAAS.
boiling time
3
amount of test portion
3
grain size
3
grain size
3
Method B - ashing + DTA
QUOVADIS workshop, October 24, 2007
Notes
Total levels
7
3
27
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.
QUOVADIS workshop, October 24, 2007
prCEN/TS 15412
Method for the determination of metallic aluminium (method B – ashing + DTA)
2,500
Sample: paper plastic fluff (QR-E)
w%
2,000
QR-E, 0.5 mm
1,500
QR-E, 1.0 mm
1,000
QR-E, 1.5 mm
0,500
Ashing of samples was made
at 550 C and 800 C,
because calcium carbonate
doesn’t degrade at 550°C.
0,000
w-%
w-%
Ash 800 °C
Ash 550 °C
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.
QUOVADIS workshop, October 24, 2007
prCEN/TS 15412
Methods for the determination of metallic aluminium
Comment
(justification for change)
Paragraph
Type
9.2
Sample
preparation
Te
Homogeneity 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
Te
For 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).”
QUOVADIS workshop, October 24, 2007
Proposed change
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
QUOVADIS workshop, October 24, 2007