SIST-TP CEN/TR 16243:2011

Ambient air quality - Guide for the measurement of elemental carbon (EC) and organic carbon (OC) deposited on filters

This Technical Report gives guidance on the measurement of elemental carbon (EC) and organic carbon (OC) following the requirement for the networks of all EU member countries to measure EC and OC in particulate matter from June 2010 at background sites according to the Council Directive 2008/50/EC on ambient air quality and cleaner air for Europe.
The Technical Report describes the analytical procedures for determining EC and OC on quartz fibre filters as μg/cm2, and the subsequent calculation of concentrations as µg/m³. Sampling onto filters is to be done in accordance with EN 14907 for PM2,5. The sampling process determines the size fraction of the particulate matter, the retention of semi-volatile material, and ab/desorption of volatile organic compounds on the filter at the time of sampling.
The same analysis method may also be used for other size fractions. Any possible additional artefacts e.g. due to charring or higher concentrations of carbonates would need to be assessed in those cases.
The measurement procedures are applicable for:
- rural background,
- urban background,
- road side and
- industrial sites.
The scope includes non rural site measurements, to allow the assessment of additional exposure of people in urban areas as stated in the objectives of the council directive and to achieve coherence in the European approach. Measurements are made over a nominal sampling period of 24 h, and concentrations are expressed as μg/m³, where the volume of air is the volume at ambient conditions near the inlet of the sampler at the time of sampling.
The applicable concentration range of the proposed method is limited by the optical correction, instrument, and thermal protocols applied in the analysis of EC and OC. Therefore no definitive values can be given. The experience from EMEP shows the applicability of the method at regional background sites.

Außenluftqualität - Leitfaden zur Messung von auf Filtern abgeschiedenem elementarem Kohlenstoff (EC) und organisch gebundenem Kohlenstoff (OC)

Dieser Technische Report gibt Anleitungen für die Messung von elementarem Kohlenstoff (EC) und organischem Kohlenstoff (OC), wobei den Anforderungen an die Messnetze aller EU-Mitgliedsländer gefolgt wird, EC und OC im Staub ab Juni 2010 im ländlichen Hintergrund entsprechend der Richtlinie 2008/50/EG des Europäischen Parlaments und des Rates über Luftqualität und saubere Luft für Europa zu messen. Dieser Technische Report beschreibt die analytischen Verfahren zur Bestimmung von EC und OC auf Quarzfaserfiltern (in μg/cm2) und der nachfolgenden Berechnung als Konzentrationen (in µg/m³). Die Probenahme von PM2,5 auf Filtern wird nach EN 14907 durchgeführt. Bedingt durch den Probenahmeprozess ergibt sich die Größenfraktion des Staubs, die Zurückhaltung des schwerflüchtigen Materials und die Ab-/Desorption von flüchtigen organischen Verbindungen auf dem Filter während der Probenahme. Das gleiche Analysenverfahren kann auch für andere Größenfraktionen verwendet werden. Jegliche zusätzlichen Artefakte, z. B. durch Verkokung oder größere Konzentration an Carbonaten, sind in diesen Fällen zu bewerten. Die Messverfahren sind anwendbar für:
- ländlichen Hintergrund,
- städtischen Hintergrund,
- Verkehrsstandorte und
- Industriestandorte. Der Anwendungsbereich schließt Messungen an nicht-ländlichen Standorten ein, um die Bewertung der zusätzlichen Exposition von Menschen im städtischen Hintergrund zu ermöglichen, wie dies in den Zielen der Richtlinie 2008/50/EG des Europäischen Parlaments und des Rates festgehalten ist, und um eine Kohärenz in dem europäischen Ansatz zu erreichen. Die Messungen werden über eine nominale Probenahmedauer von 24 h durchgeführt und die Konzentrationen in μg/m³ angegeben, wobei das Luftvolumen unter Umgebungs-bedingungen nahe dem Einlass des Probenahmegerätes während der Probenahme zugrunde gelegt wird.

Qualité de l'air ambiant - Guide pour le mesurage du carbone élémentaire (EC) et du carbone organique (OC) déposés sur filtre

Le présent Rapport technique définit des lignes directrices relatives au mesurage du carbone élémentaire (EC) et du carbone organique (OC) dans le cadre de l’application de la Directive européenne 2008/50/CE du Conseil concernant la qualité de l'air ambiant et un air pur pour l'Europe, préconisant depuis juin 2010, et pour tout les États membres, le mesurage de l’EC et de l’OC dans la matière particulaire au niveau de sites de fond.
Le Rapport technique décrit les modes opératoires d’analyse pour doser l’EC et l’OC sur des filtres en fibre de quartz en µg/cm2, et le calcul ultérieur des concentrations en µg/m3. L’échantillonnage sur filtre doit être effectué conformément à l’EN 14907 pour PM2,5. Le procédé d’échantillonnage détermine la fraction granulométrique de la matière particulaire, la rétention de la matière semi-volatile et l’ab/désorption des composés organiques volatils sur le filtre lors de l’échantillonnage.
La même méthode d’analyse de l’EC et de l’OC peut également être utilisée pour d’autres fractions granulométriques. Tout artéfact supplémentaire éventuel, par exemple dû à la formation de produit de pyrolyse pendant l’analyse ou à des concentrations significativement élevées en carbonates, devrait être évalué dans ce cas.
Les modes opératoires de mesurage sont applicables aux zones suivantes :
-   zones périrurales,
-   zones périurbaines,
-   zones proches d’axes routiers et
-   zones industrielles.
Le domaine d’application comprend les mesurages en zones non rurales, pour pouvoir évaluer l’exposition supplémentaire des personnes dans les zones urbaines, conformément à l’énoncé des objectifs de la Directive du Conseil et dans un souci de cohérence de l’approche européenne. Les mesurages sont réalisés sur une période d’échantillonnage nominale de 24 h, et les concentrations sont exprimées en µg/cm3, le volume d’air considéré correspondant au volume d’air sous les conditions de température et pression ambiantes à proximité de l’entrée de (...)

Kakovost zunanjega zraka - Vodilo za merjenje elementarnega ogljika (EC) in organskega ogljika (OC), zbranega na filtru

To tehnično poročilo podaja vodilo o merjenju elementarnega ogljika (EC) in organskega ogljika (OC) v skladu z zahtevami za omrežja vseh držav članic EU za merjenje EC in OC v delcih od junija 2010 naprej na zalednih območjih v skladu z Direktivo Sveta 2008/50/ES o kakovosti zunanjega zraka in čistejšem zraku za Evropo.
Tehnično poročilo opisuje analitske postopke za določevanje EC in OC na filtrih iz kremenovih vlaken v obliki μg/cm2 ter za nadaljnji izračun koncentracij v obliki µg/m³. Vzorčenje na filtrih se izvaja v skladu z EN 14907 za PM2,5. Postopek vzorčenja določa frakcijo velikosti delcev, retencijo polhlapnega materiala in ab/desorpcijo hlapnih organskih spojin na filtru med vzorčenjem.
Ista analizna metoda se lahko uporabi za frakcije drugih velikosti. V teh primerih je treba oceniti vse morebitne artefakte, npr. zaradi zoglenitve ali večjih koncentracij karbonatov.
Postopki merjenja veljajo za:
- podeželsko zaledje,
- urbano zaledje,
- obcestna območja in
- industrijska območja.
Obseg uporabe vključuje meritve na nepodeželskih območjih, kar omogoča oceno dodatne izpostavljenosti ljudi v urbanih območjih, kot je navedeno v ciljih te direktive Sveta, in doseganje skladnosti evropskega pristopa. Meritve se izvajajo v nazivnem obdobju vzorčenja 24 ur, koncentracije so izražene kot μg/m³, pri čemer je volumen zraka volumen pri zunanjih razmerah v bližini vhoda v vzorčevalnik med vzorčenjem.
Veljavni razpon koncentracije predlagane metode je omejen z optično korekcijo, instrumentom in termičnimi protokoli, ki se uporabljajo pri analizi EC in OC. Zato ni mogoče navesti definitivnih vrednosti. Izkušnje iz EMEP kažejo, da je metoda uporabna na regionalnih zalednih območjih.

General Information

• Status: Published
• Public Enquiry End Date: 14-May-2011
• Publication Date: 21-Nov-2011
• ICS: 13.040.20 - Ambient atmospheres
• Technical Committee: KAZ - Air quality
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 19-Oct-2011
• Due Date: 24-Dec-2011
• Completion Date: 22-Nov-2011
• Ref Project: CEN/TR 16243:2011 - Ambient air quality - Guide for the measurement of elemental carbon (EC) and organic carbon (OC) deposited on filters

Standards Content (Sample)

SLOVENSKI STANDARD
SIST-TP CEN/TR 16243:2011
01-december-2011
Kakovost zunanjega zraka - Vodilo za merjenje elementarnega ogljika (EC) in
organskega ogljika (OC), zbranega na filtru
Ambient air quality - Guide for the measurement of elemental carbon (EC) and organic
carbon (OC) deposited on filters
Außenluftqualität - Leitfaden zur Messung von auf Filtern abgeschiedenem elementarem
Kohlenstoff (EC) und organisch gebundenem Kohlenstoff (OC)
Qualité de l'air ambiant - Guide pour le mesurage du carbone élémentaire (EC) et du
carbone organique (OC) déposés sur filtre
Ta slovenski standard je istoveten z: CEN/TR 16243:2011
ICS:
13.040.20 Kakovost okoljskega zraka Ambient atmospheres
SIST-TP CEN/TR 16243:2011 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST-TP CEN/TR 16243:2011

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SIST-TP CEN/TR 16243:2011


TECHNICAL REPORT
CEN/TR 16243

RAPPORT TECHNIQUE

TECHNISCHER BERICHT
August 2011
ICS 13.040.20
English Version
Ambient air quality - Guide for the measurement of elemental
carbon (EC) and organic carbon (OC) deposited on filters
Qualité de l'air ambiant - Guide pour le mesurage du Außenluftqualität - Leitfaden zur Messung von auf Filtern
carbone élémentaire (EC) et du carbone organique (OC) abgeschiedenem elementarem Kohlenstoff (EC) und
déposés sur filtre organisch gebundenem Kohlenstoff (OC)


This Technical Report was approved by CEN on 18 June 2011. It has been drawn up by the Technical Committee CEN/TC 264.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, 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: Avenue Marnix 17, B-1000 Brussels
© 2011 CEN All rights of exploitation in any form and by any means reserved Ref. No. CEN/TR 16243:2011: E
worldwide for CEN national Members.

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Contents Page
Foreword .3
Introduction .4
1 Scope .6
2 Terms, definitions and abbreviations .6
3 Principle .7
4 Materials and instruments .8
5 Sampling .9
6 Transport and storage . 10
7 Analysis . 10
8 Artefacts and interferences . 12
9 Quality assurance/quality control (QA/QC) . 14
10 Calculation of concentrations of EC and OC . 16
11 Data reporting . 17
Annex A (informative)  Example of a logbook . 18
Annex B (informative)  An example of a standard operating procedure for analysing EC and OC . 19
Annex C (informative)  Methods for the assessment of carbonate carbon . 24
Annex D (informative)  Preparation of stock sucrose solutions and calibration standards . 28
Bibliography . 29

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Foreword
This document (CEN/TR 16243:2011) has been prepared by Technical Committee CEN/TC 264 “Air quality”,
the secretariat of which is held by DIN.
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.

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Introduction
For air quality across the European Union to be assessed on a consistent basis, Member States need to
employ standard measurement techniques and procedures. The aim of this Technical Report is to present
guidance on the measurement procedures to be followed when monitoring elemental carbon (EC) and organic
carbon (OC) deposited on filters, following Council Directive 2008/50/EC on ambient air quality and cleaner air
for Europe [1]. This requires the chemical speciation of the sub-2,5 µm size fraction of suspended particulate
matter (PM ) in ambient air, as described in Annex IV:
2,5
MEASUREMENTS AT RURAL BACKGROUND LOCATIONS IRRESPECTIVE OF CONCENTRATION
A. Objectives
The main objectives of such measurements are to ensure that adequate information is made available on
levels in the background. This information is essential to judge the enhanced levels in more polluted areas
(such as urban background, industry related locations, traffic related locations), assess the possible
contribution from long-range transport of air pollutants, support source apportionment analysis and for the
understanding of specific pollutants such as particulate matter. It is also essential for the increased use of
modelling in urban areas.
B. Substances
Measurement of PM shall include at least the total mass concentration and concentrations of appropriate
2,5
compounds to characterise its chemical composition. At least the list of chemical species given below shall
2– + + 2+ – + – 2+
be included. SO , Na ,NH , Ca , elemental carbon (EC), NO , K , Cl , Mg , organic carbon (OC)
4 4 3
C. Siting
Measurements should be taken in particular in rural background areas in accordance with parts A, B and C
of Annex III
The method described in this Technical Report is focused primarily on harmonization and improvement of the
data quality of thermal-optical measurement method for EC and OC used in monitoring networks, with
guidance regarding the different protocols (analytical parameters) used currently within that method. The
method is seen to be suitable for practical use in routine monitoring networks.
There are no traceable primary reference materials available for EC and OC analysis and there is no absolute
scientific distinction between EC and OC. Therefore, the method set out in this Technical Report provides
operational definitions of the measured quantities.
In February 2009, a workshop took place to provide an overview of the measurements made in Europe and
worldwide. The workshop was organised by the Joint Research Centre in Ispra, Italy. The report of this
workshop is available [2]. Consensus was reached for the following ranking of measurement techniques:
a) thermal method with optical correction for EC and OC for samples collected on filters,
b) other off-line analysis techniques for EC and OC for samples collected on filters,
c) other on-line analysis techniques for EC and OC for samples collected on filters,
d) other analysis techniques for either EC and/or OC,
e) other analysis techniques measuring surrogates for either EC and/or OC (i.e. light absorption).
Due to the fact that the networks of the EU member countries have to measure EC and OC starting in June
2010 and CEN/TC 264/WG 35 “EC/OC in PM” has neither a mandate nor other funding available to perform
necessary validation trials, WG 35 agreed on the following resolutions:
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1) Resolution 35
Given
 the urgent need for Member States to have a standardised method for EC and OC, as they are due
to start sampling from June 2010, and
 in the absence of a mandate from the Commission,
the WG agrees that they will work on a CEN Technical Report for EC and OC as a priority. The text of the
Technical Report will be made available to interested people (e.g. network operators) when it is ready. This
TR will describe several protocols for thermal-optical methods that will give different results for EC and OC,
because validation data is needed both to specify one standard method and to properly characterise that
method. If a mandate is given, the priorities will be reconsidered at the time.
2) Resolution 36
WG 35 agrees that the Commission shall be formally informed that the Technical Report will be an
unsatisfactory substitute for a full standard, as it will delay the start of comparable data across the EU –
variations of more than 100 % for EC can be expected. It may also have financial consequences for some
Member States who have to change their method when the standard is produced.
3) Resolution 37
WG 35 agrees that the Technical Report shall include optical charring correction using both transmittance
and reflection data, and recording of results using both sets of data shall be encouraged.
There are some open issues on the measurement procedure that can only be decided after further validation,
e.g.:
 the applicable concentration ranges of the proposed method are limited by the optical correction and
thermal protocols applied in the analysis of EC and OC; since the latter is dependent on the instrument as
well as the chosen protocols no definitive values can be given;
 temperature measurement in the instrument ovens: location and reproducibility;
 influence of sampling artefacts on the data quality;
 provision and use of reference materials.
Attention is given to harmonizing the sampling with that for anions and cations in PM as far as possible. The
2,5
measurements for anions and cations are described in prCEN/TR 264125:2010 [3] and those for PM in
2,5
EN 14907:2005 [4].
NOTE: EN 14907:2005 is under revision and will be incorporated in the revision of EN 12341:1998 Ambient air quality
– Standard gravimetric measurement method for the determination of the PM mass fraction of suspended particulate
10
matter.
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1 Scope
This Technical Report gives guidance on the measurement of elemental carbon (EC) and organic carbon
(OC) following the requirement for the networks of all EU member countries to measure EC and OC in
particulate matter from June 2010 at background sites according to the Council Directive 2008/50/EC on
ambient air quality and cleaner air for Europe.
The Technical Report describes the analytical procedures for determining EC and OC on quartz fibre filters as
2
µg/cm , and the subsequent calculation of concentrations as µg/m³. Sampling onto filters is to be done in
accordance with EN 14907 for PM . The sampling process determines the size fraction of the particulate
2,5
matter, the retention of semi-volatile material, and ab/desorption of volatile organic compounds on the filter at
the time of sampling.
The same analysis method may also be used for other size fractions. Any possible additional artefacts e.g.
due to charring or higher concentrations of carbonates would need to be assessed in those cases.
The measurement procedures are applicable for:
 rural background,
 urban background,
 road side and
 industrial sites.
The scope includes non rural site measurements, to allow the assessment of additional exposure of people in
urban areas as stated in the objectives of the council directive and to achieve coherence in the European
approach. Measurements are made over a nominal sampling period of 24 h, and concentrations are
expressed as µg/m³, where the volume of air is the volume at ambient conditions near the inlet of the sampler
at the time of sampling.
The applicable concentration range of the proposed method is limited by the optical correction, instrument,
and thermal protocols applied in the analysis of EC and OC. Therefore no definitive values can be given. The
experience from EMEP shows the applicability of the method at regional background sites.
2 Terms, definitions and abbreviations
For the purposes of this document, the following terms and definitions apply.
2.1 Terms and definitions
2.1.1
total carbon
TC
total quantity of carbon atoms in a PM sample, whatever the constituent it belongs to. This includes EC, OC
and IC
NOTE It is understood that the measure of TC released from a PM sample in a specified thermal desorption and
oxidation process may be different for different protocols, and that it will not necessarily be all of the carbon atoms in the
sample.
2.1.2
elemental carbon
EC
fraction of the non-IC total carbon in a PM sample, characterised by its non-volatility according to a specified
thermal / optical protocol. EC evolves from the sample by oxidation only
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2.1.3
organic carbon
OC
fraction of the non-IC total carbon in a PM sample that is volatilised or pyrolyzed in a specified thermal/optical
protocol
2.1.4
inorganic carbon
IC
fraction of carbon belonging to mineral species, including carbonates and other molecules
2.1.5
carbonate carbon
CC
fraction of carbon belonging to a carbonate group
NOTE Carbonate carbon (mainly CaCO and MgCO ) is viewed as the only inorganic carbon fraction being released
3 3
within the temperature range used in the thermal protocols.
2.1.6
sampling artefact
ab(d)sorption of gaseous species in (on) a PM sampling substrate (positive sampling artefact), and
volatilization of particulate species from a PM sampling substrate (negative sampling artefact)
2.1.7
PM
x
particulate matter suspended in air which passes through a size-selective inlet with a 50 % efficiency cut-off at
x µm aerodynamic diameter
2.2 Abbreviations
PM Particulate Matter
EMEP Co-operative Programme for Monitoring and Evaluation of the Long-range Transmission of
Air Pollutants in Europe
EUSAAR European Super-sites for Atmospheric Aerosol Research
NIOSH National Institute for Occupational Safety and Health
IMPROVE US-Interagency Monitoring of Protected Visual Environments
TOR Thermal Optical Reflectance
TOT Thermal Optical Transmission
SOP Standard Operating Procedure
PC Pyrolytic carbon
3 Principle
The method for measuring EC and OC in ambient PM samples deposited on filters is based on the
volatilisation and oxidation of carbon-containing PM components, the quantification of the carbonaceous
gases released, with optical correction for the charring of organic to elemental carbon in the process (the
thermal-optical method). The procedure described is a thermal-optical transmittance/reflectance (TOT/TOR)
method, which is widely used in networks like EMEP, GAW (Global Atmosphere Watch), STN (US-Speciation
Trend Network) and IMPROVE. This method can be implemented with various commercial instruments.
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4 Materials and instruments
4.1 Materials
4.1.1 Gases
The use of high purity gases, with low moisture content, is recommended:
 helium at least 99,999 % (% by volume);
 hydrogen at least 99,997 % (% by volume).
4.1.2 Standard solution
Carbon-containing standard solutions (typically sucrose), with an accurately determined concentration ranging
-1 -1
e.g. from 0,4 µg C µl to 4 µg C µl . Calibrating standard solutions should be prepared which cover the
concentration range of the samples to be analysed.
4.1.3 Other materials
 precision puncher,
 quartz boat for the filter punch,
 stainless steel tweezers for sample handling,
 clean cutting surface (e.g. aluminum foil or quartz fibre filter),
 analytical syringe or pipette for calibration using standard solutions, e.g. 10 µl volume.
4.2 Instruments
4.2.1 Sampling instruments
The performance requirements of the sampling instrument are given in EN 14907.
4.2.2 Analytical instruments
A Thermo-Optical Analyser that allows EC and OC partitioning based on optical correction of charring by
using the light transmission and/or light reflectance of the sample. Preferably, analysers that allow for
simultaneous optical correction by both methods (transmission and reflectance) should be used.
4.2.2.1 Performance requirements of the analytical instrument
Thermo-Optical EC and OC Analyser,
 the instrument detection limit should be 0,2 µg carbon per cm² of filter;
 the stability of repeated TC measurements of an external standard (e.g. sucrose solution) should be
2
± 10 % or ± 0,5 µg C/cm² (if 10 % would be less than 0,5 µg C/cm ) over a working day (see 9.1.2.2).
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5 Sampling
5.1 Filter material
Quartz fibre filters should be used. It is known that some quartz filters contain binding materials (e.g. silica
glass). The use of quartz fibre filters without binding materials is recommended.
Filters should be taken from large batches of nominally identical filters. Filters should be uniquely identified
and records kept to allow the identification of each filter with the manufacturer, purchase date, and where
possible, manufacturer’s batch and pack number.
Before field measurements are started, the filter batch(es) should be assessed for blank levels of EC and OC
using the measurement method to be used for the field samples. Typically only OC will be present in
significant quantities.
This assessment should cover:
 average blank concentrations,
 blank concentration variability.
Specific causes of blank variability such as higher blank values on filters closest to the top and bottom of the
manufacturers’ plastic containers should be investigated.
The details of the assessment of the filter material are not specified further in this Technical Report. The
procedure used and results should be reported. When the assessment gives cause for concern (as discussed
further below and in Clause 9), either the filters should be fired (see below) or alternative batches of filters
should be obtained. Ongoing requirements for checks on the filter material are given in Clause 9.
5.2 Pre-treatment of filter material and handling
Blank values and the corresponding standard deviation need to be low compared to the expected measured
values. In general, pre-treatment (firing) is not needed if the average OC content is ≤ 2 µg C/cm² and the
standard deviation of the OC content is ≤ 1 µg C/cm².
It is not unusual to fire filters before use, mainly to minimize OC levels in filters before using the filters. If firing
is used, an assessment of blank values in the fired filters, similar to the assessment of unfired filters, should
be carried out. If filters are pre-fired they should be heated at a minimum of 500 °C for a minimum of 1 h.
NOTE The main reason not to fire filters is to allow the use of the same filters for other purposes such as PM2,5
measurement. Since firing can affect the handling and weighing results (due to water absorption and brittle filter material,
for example) it is not generally recommended.
5.3 Conditioning and handling before and after sampling
The transport and storage details for filters are covered in Clause 7 and Clause 9.
5.4 Sampling duration and frequency
For the purposes of this Technical Report, the sampling period should be as required in EN 14907, i.e. close
to 24 h. Other sampling durations may be chosen as needed for the measurement task., A sequential sampler
(usually with 14 filters and one field blank) is also allowed.
th
In the absence of specific guidance, the monitoring frequency set out in the 4 Daughter Directive
2004/107/EC for indicative measurements can be used to determine the annual average EC and OC
concentrations.
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5.5 Field sampling and type of sampler
Sampling should be carried out in accordance with one of the standard methods of EN 14907, or an
equivalent method. It is acknowledged that the sampling process determines the size fraction of the
particulate matter, the retention of semi-volatile material, and ab/desorption of volatile organic compounds on
the filter at the time of sampling.
5.6 Site types
In the 2008/50/EC Directive the requirement for EC and OC measurements is limited to “rural background
areas”. However, the aim of this Technical Report is to provide guidance on standardised methods that can be
used at other types of monitoring site, including suburban, urban background, urban roadside and industrial
sites.
5.7 Filter environment during sampling
The sampler can be located either indoors or outdoors. It is known that in both situations the sampled air
temperature can deviate from ambient conditions, and this will have some effect on measured OC
concentrations. At this stage, no specific demands on temperature control beyond those given in EN 14907
are given, but the sampling temperature should be kept as close as possible to ambient conditions.
6 Transport and storage
6.1 Handling
Filters have to be handled with clean tweezers, away from contamination sources (e.g. cigarette smoke and
organic solvent vapours – including solvent based pens).
Transport and storage of filters should be performed in a clean container. They should be stored in individual
containers, at least after sampling.
6.2 Time and temperature limits
Filters should not be kept longer than 16 days in the field. Transport and storage in the laboratory should be at
temperatures below 5 °C if practicable. Within 28 days after sampling, filters should either be analysed or
transferred to a refrigerator. Filters can be stored below 5 °C for a longer period. No further details can be
given at this time.
NOTE OC concentration may change depending on handling. This may lead to different results with PM
2,5
concentrations when these come from 2 filters that have been sampled in the same way but handled differently, as
different changes of OC may have occurred.
6.3 Coding
Each sample should be identified by an individual code in a way that avoids contamination of the analysed
filter punches.
7 Analysis
7.1 General
To quantify the content of EC and OC in an aerosol sample collected on a quartz fibre filter, thermal
desorption and oxidation at defined temperatures are used. Optical transmission through, or reflectance by the
sample, is used for the correction of charring of OC occurring during the first temperature steps in inert carrier
gas. CC may interfere with the determination of EC and OC (see 8.4).
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A precision tool is used to punch a defined area (punch) from the aerosol sample, which is placed into the
instrument’s oven, which is purged with helium. In mode 1 (inert carrier gas), the oven’s temperature is
increased up to a first maximum, typically in the range 550 °C to 900 °C, depending on the thermal protocol
used. OC either volatilises from the filter, or chars in/on the filter and forms pyrolytic carbon (PC). In mode 2
(oxidative carrier gas, e.g. 10 % O in He), the instrument’s quartz oven is cooled to 500 °C to 600 °C
2
(depending on the thermal protocol), and a second temperature ramp is initialised. The final temperature in
mode 2 typically in the range 800 °C to 900 °C (depending on the thermal protocol). In mode 2, EC and PC
oxidise off the sample punch and form CO . All gases evolved from the filter punch during modes 1 and 2 are
2
carried into a manganese dioxide oven where organic vapours are oxidised to carbon dioxide (CO ) gas. CO
2 2
can be detected directly (NDIR detector), or subsequently mixed with hydrogen gas (H ) and carried along
2
with the helium through a heated nickel catalyst which reduces the CO to methane (CH ). The CH is then
2 4 4
measured using a flame ionization detector (FID). Internal (e.g. methane) and external (e.g. sucrose solution)
carbon standards are used for calibration.
The function of the laser transmittance/reflectance is to correct for pyrolysis/charring of OC to PC, which can
take place when OC is heated in mode 1 of the analysis. Not correcting for charring leads to an
underestimation of OC and a corresponding overestimation of EC. This correction is made by continuously
monitoring the reflectance and/or the transmittance of the punch, which is largely dominated by PC and EC.
As charring takes place (i.e. PC is formed), the reflectance/transmittance drops, whereas it increases when
EC and/or PC oxidised. Hence, the correction is made by determining the amount of carbon oxidised in
mode 2 that is necessary to return the reflectance/transmittance back to the initial value before charring
started. This approach assumes either that PC oxidises before the original EC in mode 2, or that the light
extinction/reflection per unit mass of PC generated during the analysis is the same as the light
extinction/reflection per unit mass of the original EC, at least until the reflectance/transmittance regains its
initial value. Such assumptions are unlikely to be met. There is therefore an inherent uncertainty in the split
point between EC and OC.

Figure 1 — Simple scheme of a thermal-optical analyser
The angle for reflectance measurement may vary from one instrument to another.
7.2 Charring correction based on optical transmission or optical reflectance measurement
The choice between reflectance and transmission optical charring correction usually gives rise to differences
in the split point between EC and OC. Several parameters such as the type of site, the filter loading and PM
composition are suspected to affect the difference between reflectance and transmission based determination
of EC and OC. As it is currently impossible to advocate one or the other of these techniques based on reliable
scientific evidence, it is recommended that both optical parameters should be recorded to allow an evaluation
of charring correction a posteriori.
7.3 Thermal protocols
One of the widely used analytical protocols such as NIOSH/STN [5], IMPROVE [6] or EUSAAR-2 [7] should
be used. When possible, repeated analysis with two or more protocols should be performed.
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The analytical parameters for these 4 protocols are listed below (Table 1). Instrumental parameters should be
recorded in a logbook as suggested in Annex A. Detailed descriptions of the analytical procedures to be
implemented when using a Sunset Laboratory instrument are given in Annex B.
Table 1 — Temperature set points and plateau durations for various widely used thermal protocols
b c
NIOSH-like NIOSH 5040 IMPROVE EUSAAR_2
(quartz)
STEP T, duration T, duration T, duration T, duration

°C, s °C, s °C, s °C, s
He1 310, 60-80 250, 60 120, 150-580 200, 120
He2 475, 60 500, 60 250, 150-580 300, 150
He3 615, 60 650, 60 450, 150-580 450, 180
He4 870, 90 850, 90 550, 150-580 650, 180
He No heating, 50  No heating, 30
a
He/O 1 550, 45-60 650, 30 550, 150-580 500, 120
2
He/O 2 625-650, 45-60 750, 30 700, 150-580 550, 120
2
He/O 3 700, 45-60 850, 30 800, 150-580 700, 70
2
He/O 4 770-775, 45-60 940, 120 850, 80
2
He/O5 870-890, 110-
2
165
a A mix of oxygen in helium according to the protocol.
b The temperature program for th NIOSH method is reported in [8].
c The residence time at each temperature in the IMPROVE protocol is flexible and depends on the flame ionization
detector (FID) signal. The residence time at a certain temperature ends when the FID returns to the baseline.
8 Artefacts and interferences
8.1 General
Generally, artefacts and interferences can occur during all steps measuring EC and OC. The most important
ones are
 loss of semi-volatiles from the sample during sampling,
 additional adsorption of OC during sampling,
 chemical reactions leading to losses and/or gains of OC during sampling,
 adsorption or losses during transport or storage,
 charring of OC during analysis,
 the presence of carbonates in the sampl
...