SIST EN 1948-2:2006

SLOVENSKI STANDARD
01-maj-2006
1DGRPHãþD
SIST EN 1948-2:1999
(PLVLMHQHSUHPLþQLKYLURY±'RORþHYDQMHPDVQHNRQFHQWUDFLMH3&''3&')LQ
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Stationary source emissions - Determination of the mass concentration of
PCDDs/PCDFs and dioxin-like PCBs - Part 2: Extraction and clean-up of PCDDs/PCDFs
Emissionen aus stationären Quellen - Bestimmung der Massenkonzentration von
PCDD/PCDF und dioxin-ähnlichen PCB - Teil 2: Extraktion und Reinigung von
PCDD/PCDF
Emissions de sources fixes - Détermination de la concentration massique en
PCDD/PCDF et PCB de type dioxine - Partie 2: Extraction et purification des
PCDD/PCDF
Ta slovenski standard je istoveten z: EN 1948-2:2006
ICS:
13.040.40 (PLVLMHQHSUHPLþQLKYLURY Stationary source emissions
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN 1948-2
NORME EUROPÉENNE
EUROPÄISCHE NORM
March 2006
ICS 13.040.40 Supersedes EN 1948-2:1996
English Version
Stationary source emissions - Determination of the mass
concentration of PCDDs/PCDFs and dioxin-like PCBs - Part 2:
Extraction and clean-up of PCDDs/PCDFs
Emissions de sources fixes - Détermination de la Emissionen aus stationären Quellen - Bestimmung der
concentration massique en PCDD/PCDF et PCB de type Massenkonzentration von PCDD/PCDF und dioxin-
dioxine - Partie 2: Extraction et purification de PCDD/PCDF ähnlichen PCB - Teil 2: Extraktion und Reinigung von
PCDD/PCDF
This European Standard was approved by CEN on 23 January 2006.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European
Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national
standards may be obtained on application to the Central Secretariat or to any CEN member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the official
versions.
CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,
Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania,
Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36  B-1050 Brussels
© 2006 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 1948-2:2006: E
worldwide for CEN national Members.

Contents Page
Foreword .3
Introduction.6
1 Scope .7
2 Normative references .7
3 Terms and definitions.7
4 Symbols and abbreviations.10
5 Principle of the extraction and clean-up procedure.11
6 Device, materials and C -labelled standards .12
7 Method validation and quality control requirements .13
8 Sample pre-treatment and extraction.14
9 Report .16
Annex A (informative)  Examples of operation of extraction and clean-up methods.17
Annex B (informative)  Relations to EU Directives.35

Bibliography.36

Foreword
This European Standard (EN 1948-2:2006) has been prepared by Technical Committee CEN/TC 264 “Air
quality”, the secretariat of which is held by DIN.
This European Standard shall be given the status of a national standard, either by publication of an identical
text or by endorsement, at the latest by September 2006, and conflicting national standards shall be
withdrawn at the latest by September 2006.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights.
This European Standard supersedes EN 1948-2:1996.
This European Standard has been prepared under a mandate given to CEN by the European Commission
and the European Free Trade Association to support Essential Requirements of EU Directive 94/67/EC of
16 December 1994 [i] on the incineration of hazardous waste. This directive is now replaced by EU Directive
2000/76/EC of 4 December 2000 on the incineration of waste [ii] and this European Standard also supports
the Essential Requirements of the new EU Directive 2000/76/EC (see also Annex B).
The precision and the performance characteristics were determined between 1992 and 1995 in four
comparative and validation trials at waste incinerators sponsored by the European Commission, the European
Free Trade Association and the German Federal Environment Agency.
The revision of this EN between 2001 and 2004 only refers to the normative part. The information given in the
informative annexes as examples of operation are kept unchanged, as they represent the state of the art at
time of the validation measurements of EN 1948:1996 between 1992 and 1995.
This European Standard EN 1948:2006 consists of three parts dealing with the determination of the mass
concentration of PCDDs and PCDFs in stationary source emissions:
Part 1: Sampling of PCDDs/PCDFs;
Part 2: Extraction and clean-up of PCDDs/PCDFs;
Part 3: Identification and quantification of PCDDs/PCDFs.
All three parts are necessary for the performance of the dioxin measurements.
In addition for the sampling, extraction and analyses of dioxin-like PCBs the Technical Specification
CEN/TS 1948-4 is developed and will be transferred to a European Standard after corresponding validation
measurements or after an approval time of three years respectively.
Important changes made in the revision of EN 1948-2:
1. Title: Broadening of the title with regard to the future EN 1948-4 for the determination of dioxin-like
PCBs
2. Foreword:
) To be published.
• Deletion of all precursor documents which were basis for elaboration of EN 1948 as well as the
names of the standardisation bodies involved in the elaboration of EN 1948
• Update of the hint regarding mandate of the standardisation project and regarding fulfilment of
the Essential Requirements of EU Directives 94/67/EC and 2000/76/EC
• Addition of a hint, that the revision only refers to the normative parts of the standard. The
Informative Annex A “Examples of operation” is kept unchanged and represents the state of the
art at time of the validation measurements of EN 1948:1996 between 1992 and 1995
• Addition of hint with regard to the future document EN 1948-4 dealing with the analyses of dioxin-
like PCBs
3. Scope:
• Addition of a hint, that EN 1948 can be applied for wide concentration ranges and various
emission sources
• Addition of a hint, that the described measurement methods are suitable for determination of
other low-volatile substances, e.g. of dioxin-like PCBs
4. Normative references:
• Update of the references to EN 1948-1:2006, EN 1948-3:2006
5. Clause 3 Terms and definitions:
• Distinction between Clause 3 "Terms and definitions" and Clause 4 "Symbols and abbreviations"
resulting in a different numbering of the following chapters
• Corrected definition of "field blank" for clarification
• Corrected definition of "analytical blank" for clarification
• Corrected definition of "sampling standard": only furans
• "Syringe standard" renamed to read "recovery standard"
• Corrected definition of "recovery standard": only dioxins
• Additional definition of "dioxin-like PCBs"
• "Sampling volume" renamed to read "volume of the sampling extract"
• Corrected definition and requirement of isokinetic sampling according to EN 13284-1:2001
• Additional definition and calculation of limit of detection
• Additional definition and calculation of limit of quantification
• Additional definition of WHO-TEF/WHO-TEQ
6. Clause 5 Principle of the extraction and clean-up procedure: Additional subclause 5.2 "Minimum
information prior to analyses"
7. Clause 7.2 Sample pre-treatment: Correction of the requirements regarding sample pre-treatment
for better comprehensibility
8. Clause 8.1 Addition of extraction standards: Correction for better comprehensibility
9. Clause 8.2 Sample storage: Requirement to store the samples < 4 °C was deleted and replaced by
"in the dark not higher than room temperature (approximately 25 °C)."
10. Clause 8.3 Extraction: Requirement to carry out principally a sample pre-treatment with HCL was
placed at first position.
11. Correction of title "Check of adsorbent activity"
Annex A.2.1.4.4:
12. Annex A.4.3: Correction: the dioxin-like (not the planar) PCB are separated from PCDD/F
13. Figure A.4 Caption: Correction: dioxin-like PCB (not planar PCB) are adsorbed
14. Annex B: Update of the hint regarding mandate of the standardisation project and regarding fulfilment
of basic requirements of EU Directives 94/67/EC and 2000/76/EC
15. Bibliography: Update
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to implement this European Standard: Austria, Belgium, Cyprus, Czech Republic,
Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden,
Switzerland and the United Kingdom.

Introduction
Two groups of related chlorinated aromatic ethers are known as polychlorinated dibenzodioxins (PCDDs) and
polychlorinated dibenzofurans (PCDFs); they consist of a total of 210 individual substances (congeners):
75 PCDDs and 135 PCDFs.
PCDDs and PCDFs can form in the combustion of organic materials; they also may occur as undesirable by-
products in the manufacture or further processing of chlorinated organic chemicals. PCDDs/PCDFs enter the
environment via these emission paths and through the use of contaminated materials. In fact, they are
universally present in very small concentrations. The 2,3,7,8-chlorine substituted congeners are toxicologically
significant. Toxicologically much less significant than the tetrachlorinated to octachlorinated
dibenzodioxins/dibenzofurans are the 74 monochlorinated to trichlorinated dibenzodioxins/dibenzofurans (for
toxicity equivalent factors, see Annex A of EN 1948-1:2006).
Only skilled operators who are trained in handling highly toxic compounds should apply the method described
in this European Standard.
1 Scope
This European Standard specifies the extraction and clean-up procedures of the sampled PCDDs/PCDFs. It is
an integral part of the complete measurement procedure. The use of the other two parts EN 1948-1:2006 and
EN 1948-3:2006 describing sampling or identification and quantification, respectively, is necessary for the
determination of the PCDDs/PCDFs.
This European Standard has been designed to measure PCDD/PCDF concentrations at about
0,1 ng I-TEQ/m in stationary source emissions.
This European Standard specifies both method validation and a framework of quality control requirements
which shall be fulfilled by any PCDD/PCDF extraction and clean-up methods to be applied. Some methods
are described in detail in Annex A as examples of proven procedures.
Each of the three sampling methods (Part 1) can be combined with the extraction and clean-up (Part 2) and
the identification and quantification (Part 3) to complete the measurement procedure.
During comparison measurements of the three sampling methods on municipal waste incinerators at the level
of about 0,1 ng I-TEQ/m these methods have been deemed comparable within the expected range of
uncertainty. Validation trials were performed on the flue gas of municipal waste incinerators at the level of
3 3 3
about 0,1 ng I-TEQ/m and a dust loading of from 1 mg/m to 15 mg/m . Although this European Standard is
primarily developed and validated for gaseous streams emitted by waste incinerators, the practical experience
shows that it can be applied for wide concentration ranges and various emission sources.
The procedure described in the three parts of EN 1948:2006 specifies requirements which shall be met in
order to measure the 17 congeners necessary to calculate the total I-TEQ (see Table A.1 of
EN 1948-1:2006).
Besides the determination of PCDDs/PCDFs the described measurement methods are suitable for
determination of other low-volatile substances, e.g. of dioxin-like PCBs (details for sampling and analyses see
CEN/TS 1948-4), although no validated performance characteristics are available yet.
2 Normative references
The following referenced documents are indispensable for the application of this European Standard. For
dated references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
EN 1948-1:2006, Stationary source emissions — Determination of the mass concentration of PCDDs/PCDFs
and dioxin-like PCBs — Part 1: Sampling of PCDDs/PCDFs
EN 1948-3:2006, Stationary source emissions — Determination of the mass concentration of PCDDs/PCDFs
and dioxin-like PCBs — Part 3: Identification and quantification of PCDDs/PCDFs
3 Terms and definitions
For the purposes of this European Standard, the terms and definitions given in EN 1948-1:2006,
EN 1948-3:2006 and the following apply.
3.1
analytical blank value
value determined by a blank sample covering the complete analytical procedure including extraction, clean-up,
identification and quantification including all the relevant reagents and materials
3.2
congener
any one of the 210 individual PCDDs/PCDFs
3.3
dioxin-like PCBs
any PCB showing similar toxicity as the 2,3,7,8-substituted PCDDs/PCDFs according to WHO [iii]
3.4
extraction standard
C -labelled 2,3,7,8-chlorine substituted PCDD/PCDF, added before extraction and used for calculation of
results
3.5
field blank value
value determined by a blank sample covering a specific procedure used to ensure that no significant
contamination has occurred during all steps of the measurement and to check that the operator can achieve a
quantification level adapted to the task
3.6
isokinetic sampling
sampling at a flow rate such that the velocity and direction of the gas entering the sampling nozzle are the
same as the velocity and direction of the gas in the duct at the sampling point
[EN 13284-1:2001, definition 3.5 [iv]]
3.7
keeper
high boiling point solvent added to the sampling standard solution
3.8
limit of detection (LOD)
minimum value of the measurand for which the measuring system is not in the basic state, with a stated
probability
NOTE 1 The limit of detection, also referred to as capability of detection, is defined by reference to the applicable basic
state. But it may be different from "zero", for instance for oxygen measurement as well as when gas chromatographs are
used.
[prEN ISO 9169:2004, definition 3.2.6 [v]]
NOTE 2 The measurement value can be distinguished from the analytical blank value with a confidence of 99 %. The
limit of detection is expressed as the mean analytical blank value (b ) plus three times the standard deviation of the
ave
analytical blank (s ).
b
LOD =b + 3s (1)
ave b
where
LOD is the detection limit;
b is the mean analytical blank value;
ave
s is standard deviation of the analytical blank.
b
NOTE 3 In this European Standard the limit of detection should preferably be calculated from the analytical blank b .
ave
If this is not possible, the limit of detection can be calculated from the signal to noise ratio according to EN 1948-3:2006,
8.1.
3.9
limit of quantification (LOQ)
limit above which a quantification of the measurand is possible, expressed as the mean analytical blank value
plus, either, five to ten times the standard deviation of the analytical blank. The factor F depends to the
accepted measurement uncertainty.
LOQ =b + F s (2)
ave b
where
LOQ is the quantification limit;
b is the mean analytical blank value;
ave
s is standard deviation of the analytical blank.
b
NOTE In this European Standard the limit of quantification should preferably be calculated from the analytical blank
b . If this is not possible, the limit of quantification can be calculated from the signal to noise ratio according to
ave
EN 1948-3:2006, 8.1 using the requirement of EN 1948-3:2006, 8.3e.
3.10
pattern
defined as a chromatographic print of any series of PCDD/PCDF isomers
3.11
PCDD/PCDF isomers
PCDDs or PCDFs with identical chemical composition but different structure
3.12
profile
graphic representation of the sums of the isomer concentrations of the PCDDs and the PCDFs
3.13
recovery standard
C -labelled 2,3,7,8-chlorine substituted PCDD, added before injection into the GC
3.14
sampling standard
C -labelled 2,3,7,8-chlorine substituted PCDF, added before sampling
3.15
spiking
addition of C -labelled PCDD/PCDF standards
3.16
WHO-TEF
toxic equivalent factor proposed by WHO [iii] (for detailed description see EN 1948-1:2006, Annex A)
3.17
WHO-TEQ
toxic equivalent obtained by multiplying the mass determined with the corresponding WHO-TEF including
PCDDs, PCDFs, and PCBs (for detailed description see EN 1948-1 Annex A)
NOTE WHO-TEQ , WHO-TEQ should be used to distinguish different compound classes.
PCB PCDD/PCDF
4 Symbols and abbreviations
4.1 General
HRGC
high resolution gas chromatography
HRMS
high resolution mass spectrometry
I-TEF
international toxic equivalent factor (for detailed description, see Annex A of EN 1948-1:2006)
I-TEQ
international toxic equivalent obtained by weighting the mass determined with the corresponding I-TEF (for
detailed description, see Annex A of EN 1948-1:2006)
LOD
limit of detection
LOQ
limit of quantification
PCB
polychlorinated biphenyl
PCDD/PCDF
polychlorinated dibenzo-p-dioxin/dibenzofuran
PTFE
polytetrafluoroethylene
PU foam
polyurethane foam
WHO-TEF
toxic equivalent factor of the World Health Organisation
WHO-TEQ
toxic equivalent of the World Health Organisation
4.2 Congeners of PCDD/PCDF
TCDD
Tetrachlorodibenzo-p-dioxin
PeCDD
Pentachlorodibenzo-p-dioxin
HxCDD
Hexachlorodibenzo-p-dioxin
HpCDD
Heptachlorodibenzo-p-dioxin
OCDD
Octachlorodibenzo-p-dioxin
TCDF
Tetrachlorodibenzofuran
PeCDF
Pentachlorodibenzofuran
HxCDF
Hexachlorodibenzofuran
HpCDF
Heptachlorodibenzofuran
OCDF
Octachlorodibenzofuran
5 Principle of the extraction and clean-up procedure
5.1 Principles
The determination of PCDDs/PCDFs is based on quantification by the isotope-dilution technique using
HRGC/HRMS. C -labelled 2,3,7,8-chlorine substituted PCDD/PCDF congeners are added at different
stages of the whole method. Losses during extraction and clean-up can be detected and compensated by
using these added congeners as internal standards for quantification together with recovery standards which
are added just before the HRGC/HRMS analysis. However, due to possible differences in the binding and
adsorption characteristics between the native PCDDs/PCDFs and the C -labelled congeners, which are
added during analysis, complete substantiation of the extraction efficiency and compensation of losses during
clean-up is not guaranteed. Therefore, in addition the applied methods shall be validated thoroughly.
Examples of well-proven extraction and clean-up methods are described in detail in Annex A.
The main purpose of the clean-up procedure of the raw sample extract is the removal of sample matrix
components, which may overload the separation method, disturb the quantification or otherwise severely
impact the performance of the identification and quantification method. Furthermore, an enrichment of the
analytes in the final sample extract is achieved. Extraction procedures are normally based on soxhlet
extraction of filters and adsorbents, and liquid extraction of the condensate. Sample clean-up is usually carried
out by multi-column liquid chromatographic techniques using different adsorbents.
In principle any clean-up method can be used which recovers the analytes in sufficient quantities. Furthermore,
the final sample extract shall not affect adversely the performance of the analytical system or the
quantification step. However, all applied methods shall be tested thoroughly and shall pass a set of method
validation requirements before they can be employed for emission surveillance. In addition, the verification of
the method performance for each single sample shall be part of the applied quality assurance protocol. This
European Standard describes a framework of method validation and quality control requirements which shall
be fulfilled by any applied method.
In the present European Standard the minimum requirements for extraction and clean-up to be met are
described as well as examples of operation.
5.2 Minimum information prior to analyses
a) Sampling volume;
b) type of plant;
c) abatement technologies;
d) expected concentration and/or emission limit value.
6 Device, materials and C -labelled standards
6.1 Device and materials
See examples of operation in Annex A.
6.2 C -labelled standards
The extraction standards (see Table 1) shall be added to the different sampling media before extraction.
These C -labelled congeners behave equally to the extracted native PCDDs/PCDFs during clean-up due to
their similar chemical and physical properties. Consequently, they are used for quantification.
The quantities of the C -labelled congeners to be added per sample for sampling at the concentration level
3 3
of 0,1 ng I-TEQ/m and 10 m sampling volume (dry gas) are given in Table 1.
If a considerably higher or lower mass of native PCDDs/PCDFs is expected in the sample, the masses of the
C -labelled standards to be added shall be adapted accordingly.
Table 1 — C -labelled 2,3,7,8-chlorine substituted PCDDs/PCDFs congeners to be added to the
3 3
sample at different stages of the procedure for measurement of 0,1 ng I-TEQ/m assuming 10 m of
sampling volume
Total amount in pg added before:
Sampling Extraction GC Injection
Solution: (sampling standard) (extraction standard) (recovery standard)

Total volume in µl: 100 100 25
(e.g. toluene, n-nonane)
Congeners added
C -2,3,7,8-TCDF 400
C -1,2,3,4-TCDD 400
C -2,3,7,8-TCDD 400
C -1,2,3,7,8-PeCDF 400
C -2,3,4,7,8-PeCDF 400
C -1,2,3,7,8-PeCDD 400
C-1,2,3,4,7,8-HxCDF 400
C -1,2,3,6,7,8-HxCDF 400
C -1,2,3,7,8,9-HxCDF 400
C -2,3,4,6,7,8-HxCDF 400
C -1,2,3,4,7,8-HxCDD 400
C -1,2,3,6,7,8-HxCDD 400
C -1,2,3,7,8,9-HxCDD 400
C -1,2,3,4,6,7,8-HpCDF 800
C12-1,2,3,4,7,8,9-HpCDF 800
C -1,2,3,4,6,7,8-HpCDD 800
C -OCDF 800
C -OCDD 800
7 Method validation and quality control requirements
7.1 Use of C -labelled standards
C -labelled 2,3,7,8-chlorine substituted PCDDs/PCDFs are added before sampling (sampling standards),
before extraction (extraction standards) and just before the GC injection (recovery standards). The recovery
standards are assumed to be transferred to the analytical system without any loss and allow to determine the
recoveries (or losses) of the congeners added at earlier stages.
Sampling standards are added to the sampling device before starting sampling. C -labelled congeners
introduced at this stage might not be exposed to completely the same mechanisms of losses as the native
PCDDs/PCDFs collected during the sampling period. First, the labelled congeners are exposed to the gas flow
during the entire sampling time while the native PCDDs/PCDFs are present only half the time on average.
Second, a significant fraction of the sampled native PCDDs/PCDFs is bound to particles and, therefore, they
may have different susceptibilities to reactions and mechanisms which might lead to losses. Consequently, as
different studies have shown, C -labelled congeners added prior to sampling might be subject to loss
mechanisms. Their use as internal standards for quantification may lead to an overestimation of the found
concentrations. Therefore, the only purpose of the isotope labelled standards added before sampling (see
Table 1) is to identify anomalies during sampling. They are not used for quantification.
7.2 Sample pre-treatment
The efficiency of all applied extraction methods shall be documented as part of the method description. It shall
be measured regularly and corrective action shall be taken if the extraction efficiency falls below the
acceptable requirements given below. The following validation criterion shall be fulfilled for all parts of the
sampling device that may contain a part of the sample such as (where applicable) filters,
absorbents/adsorbents, condensate, vessels and surfaces of the sampling device:
The extract of a repeated extraction procedure shall not contain more than 5 % of the amount of any individual
native congener compared with the first extraction. For the second extraction the addition of C -labelled
extraction standards is repeated.
7.3 Clean-up
7.3.1 Method validation
Sample clean-up is dependent on the type of sample matrix which shall be removed. Therefore, a single well-
defined clean-up procedure shall not be applied to all sample matrices without preliminary check.
Therefore, the following method validation requirements have been set up which allow to verify the overall
performance of the clean-up method in a sample-independent manner. The following requirements shall be
fulfilled by any clean-up procedure which is employed:
a) The isomer pattern and congener profile of a well characterised sample extract containing all
PCDD/PCDF congeners (e.g. a fly ash extract) shall not be altered by the applied clean-up procedure.
Area response changes relative to the most abundant signal of each homologue series should not exceed
20 %. Furthermore, differences between the sum responses of the PCDDs/PCDFs congener group
should not exceed 20 %.
b) The recovery rate for each of the individual congeners of the 2,3,7,8-chlorine substituted PCDDs/PCDFs
congeners added before extraction shall be at least 50 % and should not exceed 115 %.
These performance tests shall be repeated after any changes of the clean-up procedure.
In addition, the performance of the clean-up method shall be measured for each individual sample by
calculating the recovery rates of the C -labelled 2,3,7,8-chlorine substituted congeners added to the sample
prior to extraction.
7.3.2 Minimum requirements for measurements
The recovery rate of each individual 2,3,7,8-chlorine substituted PCDD/PCDF of the extraction standards shall
be within:
 50 % to 130 % for the tetra- to hexa-chlorinated congeners;
 40 % to 130 % for the hepta- and octa-chlorinated congeners.
If the above ranges are exceeded, then provided the sum of the contributions to the total I-TEQ from all the
congeners with recoveries not within these ranges does not exceed 10 %, the acceptable ranges shall be:
 30 % to 150 % for the tetra- to hexa-chlorinated congeners;
 20 % to 150 % for the hepta- and octa-chlorinated congeners.
8 Sample pre-treatment and extraction
8.1 Addition of extraction standards
The C -labelled 2,3,7,8-chlorine substituted congeners listed in Table 1 shall be added before extraction.
The extraction standards shall be split and distributed proportionally to the sampling train compartments which
are known to contain more than 20 % of the total I-TEQ of the sample. If one collection medium is suspected
to contain more than 75 % of the total I-TEQ, the whole extraction standard solution should be added to this
part.
8.2 Sample storage
All sampling media and parts of the sampling train which contain PCDDs/PCDFs shall be stored in the dark
not higher than room temperature (approximately 25 °C). The use of screw-caps with PTFE-lined seals is
recommended to avoid contamination. Aluminium-lined cardboard seals may contain PCDDs/PCDFs.
8.3 Extraction
The extraction procedure is carried out using the following materials and techniques. Detailed descriptions of
some procedures are given in Annex A. Other methods can also be used but shall be of proven equal
performance as the techniques below:
a) Pre-treatment of sampled particles with hydrochloric acid shall be part of any extraction procedure
(examples of procedures are given in Annex A) [vi].
b) Particle collecting media (glass fibre filters, thimbles, glass wool etc.): Soxhlet extraction with toluene or
comparable method.
c) Solid adsorbents (Polyurethane foam, XAD-2): Soxhlet extraction for 20 h with toluene. (Water shall be
removed, e.g. via a Dean-Stark water separator or by sodium sulphate).
d) Aqueous liquids (condensate and bubbler/impinger solution): Liquid/liquid extraction with toluene or
dichloromethane. The water/toluene volume ratio should not be greater than 20:1. Three consecutive
extractions shall be carried out.
e) Inner surfaces of tubes, vessels or other parts of the sampling device being in contact with the sample:
Rinsing with a water-miscible solvent (acetone and/or methanol) followed by toluene. Reflux boiling with
toluene is an alternative for the second step.
f) When sampling with flow division is performed, the filter part and the condenser/adsorber part may be
analyzed separately. The measured concentrations shall be added at the final stage of calculation.
g) Alternatively an aliquot of the filter extract, corresponding to the proportion of side stream to main stream
gas volume, is combined for analysis with the condenser/adsorber part. In this case, the quantity of
extraction standard solution added to the filter is increased in proportion to the ratio of main stream to
side stream gas volume.
h) If coke or activated carbon is used in the gas cleaning system of the incinerator suitable methods,
including freeze drying or Dean-Stark extraction or addition of water miscible solvents to the extraction
medium, shall be taken to remove water. Attention shall be paid to the method validation of this step.
After extraction, the organic solvents containing water shall be dried before the concentration procedure. After
combination of all extraction and rinsing solutions any volume reduction shall be carried out carefully to avoid
evaporation losses of PCDDs/PCDFs. In case evaporation to nearly dryness is necessary, the use of a small
amount (e.g. 50 µl) of a keeper (usually a high-boiling solvent such as tetradecane) is strongly recommended.
8.4 Clean-up
Clean-up methods shall prepare the sample extract in an appropriate manner for the subsequent quantitative
determination (see also 7.3). Clean-up procedures shall concentrate PCDDs/PCDFs in the extracts and to
remove interfering matrix components present in the raw extract.
Proven clean-up procedures shall be used containing normally two or more of the following techniques which
can be combined in different orders. A detailed description of some of the procedures is given in Annex A.
Other methods can also be used but shall be of proven equal performance as the techniques described
below:
a) Gel permeation chromatography:
The interesting molecular weight range for PCDDs/PCDFs of 200 g/mol to 500 g/mol can be isolated from
larger molecules and polymers which might overload other clean-up methods.
b) Multilayer column liquid chromatography using silica with different activity grades and surface
modifications:
Compounds with different chemical properties than PCDDs/PCDFs can be removed. A direct treatment of
the sample extract with sulphuric acid shall be carried out very carefully to avoid losses of PCDDs/PCDFs
on the formed carboniferous surfaces.
c) Column adsorption chromatography using activated carbon:
Planar PCDD/PCDF molecules are separated from other interfering non-planar molecules.
d) Column liquid chromatography on alumina of different activity grade and acidity/basicity:
Interfering compounds with small differences in polarity or structure compared to PCDDs/PCDFs can be
removed.
8.5 Final concentration of the sample extract
To achieve sufficient quantification limits, the cleaned sample extract shall be concentrated to a volume in the
order of 25 µl to 100 µl before quantification. (Though PCDDs/PCDFs have rather high boiling points
(> 320 °C) vapour phase transfer mechanisms and aerosol formation during solvent evaporation might lead to
substantial losses when concentrating volumes below 10 ml). Depending on the method to be used for solvent
volume reduction the following precautions shall be taken into consideration:
a) Rotary evaporators
Losses might be substantial when reducing solvent volumes below 10 ml. Counter measures are the use
of controlled vacuum conditions according to the vapour pressure and boiling point of the solvent, addition
of a high-boiling solvent as a keeper as well as the use of specially shaped vessels (e.g. V-shaped).
b) Counter gas flow evaporators
Volumes should not be reduced to less than 1 ml.
c) Nitrogen flow
An excessive flow of nitrogen which disturbs the solvent surface should be avoided. The vial shape has
also some influence on possible losses. V-shaped vials or vial inserts shall be used for volume reductions
below around 200 µl.
8.6 Addition of recovery standards
The very last step before quantification is the addition of the recovery standards to measure the recovery rates
of the extraction standards. The recovery standards according to Table 1 shall be added under following
conditions:
a) Recovery standards shall be added just prior to the quantification procedure. Samples with the recovery
standard added which could not be analysed due to operational reasons (instrument failure), should be
stored as briefly as possible and any further uncontrolled solvent evaporation shall be avoided.
b) Recovery standards shall be added after the final volume reduction. Any further direct volume reduction
shall be avoided. A slow evaporation at room temperature from the open sample vial to a volume of about
25 µl is acceptable.
9 Report
The contents of the report for sampling are described in EN 1948-1:2006 and for analysis in
EN 1948-3:2006.
Annex A
(informative)
Examples of operation of extraction and clean-up methods
A.1 General
The revision of this EN between 2001 and 2004 only refers to the normative part. The information given in this
informative annex as examples of operation are kept unchanged, as they represent the state of the art at time
of the validation measurements of EN 1948:1996 between 1992 and 1995.
Polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) are extracted from the sampling
media by soxhlet extraction, liquid/liquid extraction or rinsed with solvents (sampling train surfaces). Selected
C -isotope labelled 2,3,7,8-chlorine substituted PCDD/PCDF congeners are added to the different sampling
media before extraction. Clean-up of the sample extract is performed by liquid chromatography. C -isotope
labelled congeners are added as recovery standards just before quantification to calculate recovery rates of
the sampling and extraction standards.
A.2 Method 1
A.2.1 Equipment, chemicals and instruments
A.2.1.1 Sampling materials and cleaning of materials
A.2.1.1.1 Sampling materials
a) XAD-2, polystyrene divinylbenzene co-polymer, 0,3 mm to 0,85 mm particle size;
2 -8
b) Polyurethane foam plugs (polyether, open pored type, surface area 330 m /g, pore size 90 × 10 cm,
100 mm diameter, 50 mm thickness, density 25 kg/m produced from toluene-2.4.-diisocyanate/toluene-
2.6.-diisocyanate (TDI) and polyoxypropylene triol;
2)
c) glass fibre filters, type AE , 142 mm diameter.
A.2.1.1.2 Cleaning of XAD-2
350 ml XAD-2 are placed in a 60 mm x 180 mm thimble and cleaned in a soxhlet-extractor of 700 ml volume
first with methanol (8 h) followed by acetonitrile (8 h) and diethylether (8 h). Afterwards the adsorbent is air-
dried in a fume-hood for 48 h and in an oven at 35 °C for at least 8 h. The adsorbent is stored in a borosilicate
bottle with a polypropylene cap.
A.2.1.1.3 Cleaning of polyurethane foam (PUF) plugs
8 new plugs are placed in a 2 000 ml soxhlet extractor avoiding too much deformation. They are cleaned with
2 500 ml of the following solvents (see A.2.1.3): toluene (24 h), acetone (24 h) and toluene (8 h). After
extraction, the plugs are squeezed manually to remove the remaining solvent (fume hood!) by using solvent

2) Fibre filter, type AE, no. 64878 is the trade-name of a product supplied by Gelman, USA, and is an example of a
suitable commercially available product. This indication is only made for information of the user of this European Standard
and does not mean any approval of the named products by CEN.
resistant gloves. The moist plugs are transferred to a desiccator of 300 mm diameter which is placed into an
oven. They are dried at 60 °C under vacuum (80 kPa) for 8 h. Afterwards, each plug is wrapped into
aluminium foil and stored in a plastic bag. Storage should not exceed 2 months.
A.2.1.1.4 Cleaning of glass fibre filters
Up to 20 glass fibre filters are heated in a muffle furnace at 450 °C for 8 h. Afterwards they are wrapped into
aluminium foil.
A.2.1.2 Laboratory equipment
A.2.1.2.1 Glassware
a) Round bottom flasks, 500 ml and 1 000 ml, joint size 24/29;
b) round bottom flasks, 100 ml, with centrifuge tube of 5 ml volume fused to the bottom, joint size 24/29 (see
Figure A.1);
c) Pasteur pipettes, 150 mm and 230 mm length,
d) separation funnels with glass tap and glass stopper, 500 ml, 1 000 ml, 2 000 ml;
e) bottles made from borosilicate glass, 50 ml, 100 ml, 250 ml, 500 ml, 1 000 ml and 2 000 ml, with
polypropylene screw cap;
f) porcelain dishes, 180 mm and 250 mm diameter;
g) centrifuge tubes, conical, 10 ml;
h) glass beakers, 50 ml, 100 ml, 250 ml, 400 ml, 500 ml;
i) measuring cylinders, 100 ml, 1 000 ml, precision ± 0,75 ml and ± 5 ml, respectively at 20 °C;
j) desiccator, 300 mm diameter, cover with sleeve (without grease!).
A.2.1.2.2 Equipment for soxhlet extraction
a) Soxhlet apparatus, 200 ml or 500 ml, joint size 60/48, 25 cm long, joint size 34/35;
b) Soxhlet apparatus, 2 000 ml with joint size 34/35;
c) ball cooler, 25 cm long, joint size 34/35;
3)
d) Soxhlet thimbles, cellulose, 28 mm diameter, 80 mm long Soxhlet thimbles, cellulose, 53 mm diameter,
4)
145 mm length or 60 mm diameter, 180 mm length ;
e) socket/cone adapters, joint size 34/35 to 60/48;
f) socket/cone adapters, joint size 34/35 to 50/42;

3) Soxhlet thimbles, cellulose is the trade-name of a product supplied by Schleicher & Schüll, Germany, and is an
example of a suitable commercially available product. This indication is only made for information of the user of this
European Standard and does not mean any approval of the named products by CEN.
4) Soxhlet thimbles, cellulose is the trade-name of a product supplied by Munktell, USA, and is an example of a suitable
commercially available product. This indication is only made for information of the user of this European Standard and
does not mean any approval of the named products by CEN.
g) Polyurethane foam sheets, 3,5 cm thick, 21 cm x 21 cm for insulation of soxhlet extractor.
A.2.1.2.3 Cleaning of soxhlet thimbles
2 to 8 soxhlet thimbles are extracted in a 2 000 ml soxhlet extractor with toluene for 8 h. Afterwards they are
dried in a fume hood and wrapped into aluminium foil.
A.2.1.2.4 Cleaning of glassware
All glassware is soaked in a 2,5 % solution of detergent for 24 h, rinsed 10 times with tap water and twice with
5)
deionised water from a Millipore MilliQ plus system . The air-dried glassware is afterwards warmed up to
480 °C in a furnace for 6 h to remove remaining traces of organic material. Disposable equipment such as
Pasteur pipettes are rinsed with the solvent used afterwards.
A.2.1.3 Chemicals, solvents and adsorbents
Hexane, dichloromethane, cyclohexane, methanol and toluene are of pesticide grade quality. Benzene of
analytical grade is used.
Sodium sulphate is dehydrated at 600 °C for 8 h and stored in the original bottle.
All other chemicals and solvents are of analytical grade (potassium hydroxide, sulphuric acid, n-tetradecane;
6) 7)
azobenzene ; methylazobenzene .
8)
The following adsorbents are employed: aluminium oxide, basic, activity I ; silica, 0,063 mm to 0,20 mm,
9)
activated charcoal, 0,04 mm to 0,15 mm .
50 g cotton wool (chemically pure) is soxhlet-extracted overnight with 600 ml of dichloromethane and dried
2)
under vacuum. The procedure is repeated with 600 ml of hexane. Glass fibre filters are heated to 450 °C for
8 h.
A.2.1.4 Pre-treatment of adsorbents
A.2.1.4.1 Pre-treatment of silica
To ensure a sufficiently low blank value,
...