EN ISO 9562:2004

SLOVENSKI STANDARD
01-februar-2005
1DGRPHãþD
SIST EN 1485:1997
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Water quality - Determination of adsorbable organically bound halogens (AOX) (ISO
9562:2004)
Wasserbeschaffenheit - Bestimmung absorbierbarer organisch gebundener Halogene
(AOX) (ISO 9562:2004)
Qualité de l'eau - Dosage des composés organiques halogénés adsorbables (AOX) (ISO
9562:2004)
Ta slovenski standard je istoveten z: EN ISO 9562:2004
ICS:
13.060.50 3UHLVNDYDYRGHQDNHPLþQH Examination of water for
VQRYL chemical substances
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN ISO 9562
NORME EUROPÉENNE
EUROPÄISCHE NORM
September 2004
ICS 13.060.50 Supersedes EN 1485:1996
English version
Water quality - Determination of adsorbable organically bound
halogens (AOX) (ISO 9562:2004)
Qualité de l'eau - Dosage des composés organiques Wasserbeschaffenheit - Bestimmung absorbierbarer
halogénés adsorbables (AOX) (ISO 9562:2004) organisch gebundener Halogene (AOX) (ISO 9562:2004)
This European Standard was approved by CEN on 2 September 2004.
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, 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
© 2004 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 9562:2004: E
worldwide for CEN national Members.

Foreword
This document (EN ISO 9562:2004) has been prepared by Technical Committee ISO/TC 147
"Water quality" in collaboration with Technical Committee CEN/TC 230 "Water analysis", 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 March 2005, and conflicting national
standards shall be withdrawn at the latest by March 2005.

This document supersedes EN 1485:1996.

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, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.

Endorsement notice
The text of ISO 9562:2004 has been approved by CEN as EN ISO 9562:2004 without any
modifications.
INTERNATIONAL ISO
STANDARD 9562
Third edition
2004-09-15
Water quality — Determination of
adsorbable organically bound halogens
(AOX)
Qualité de l'eau — Dosage des composés organiques halogénés
adsorbables (AOX)
Reference number
ISO 9562:2004(E)
©
ISO 2004
ISO 9562:2004(E)
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ii © ISO 2004 – All rights reserved

ISO 9562:2004(E)
Contents Page
Foreword. iv
Introduction . v
1 Scope. 1
2 Normative references . 1
3 Terms and definitions. 1
4 Interferences. 2
5 Principle . 2
6 Reagents . 2
7 Apparatus. 4
8 Sampling and sample pre-treatment. 6
9 Procedure. 7
10 Calculation. 11
11 Precision . 11
12 Test report. 12
Annex A (informative) Determination of dissolved adsorbable organically bound halogens after
solid phase extraction (SPE-AOX) in waters with high salt content . 13
Annex B (informative) Handling of activated carbon. 18
Annex C (informative) Statistical performance characteristics . 19
Bibliography . 21

ISO 9562:2004(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies
(ISO member bodies). The work of preparing International Standards is normally carried out through ISO
technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 9562 was prepared by Technical Committee ISO/TC 147, Water quality, Subcommittee SC 2, Physical,
chemical and biochemical methods.
This third edition cancels and replaces the second edition (ISO 9562:1998), which has been technically
revised.
iv © ISO 2004 – All rights reserved

ISO 9562:2004(E)
Introduction
Adsorbable organically bound halogens (AOX) is an analytical convention. The result is a parameter used for
water quality control purposes. It represents the sum of organically bound chlorine, bromine and iodine (but
not fluorine) that can be adsorbed on activated carbon under specified conditions and, if the sample is not
filtered, includes that associated with suspended matter.
The user should be aware that particular problems could require the specification of additional marginal
conditions.
INTERNATIONAL STANDARD ISO 9562:2004(E)

Water quality — Determination of adsorbable organically bound
halogens (AOX)
WARNING — Persons using this International Standard should be familiar with normal laboratory
practice. This International Standard does not purport to address all of the safety problems, if any,
associated with its use. It is the responsibility of the user to establish appropriate safety and health
practices and to ensure compliance with any national regulatory conditions.
IMPORTANT — It is absolutely essential that tests conducted according to this International Standard
be carried out by suitably qualified staff.
1 Scope
This International Standard specifies a method for the direct determination of an amount of usually 10 µg/l in
water of organically bound chlorine, bromine and iodine (expressed as chloride) adsorbable on activated
carbon.
This method is applicable to test samples (see 9.2) with concentrations of inorganic chloride ions of less than
1 g/l. Samples with higher concentrations are diluted prior to analysis.
This method is also applicable to samples containing suspended solids where halogens are adsorbed onto the
solid matter (e.g. insoluble halides). Filtration of the sample before analysis allows the separate determination
of dissolved and particulate adsorbable organically bound halogens (AOX).
Filtered samples with high inorganic chloride content can be analysed by a modified method [dissolved
adsorbable organically bound halogens after solid phase extraction in waters with high salt content (SPE-
AOX)] (see Annex A). However, results obtained by this modified method can differ significantly from those of
the required method.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
ISO 1773:1997, Laboratory glassware — Narrow-necked boiling flasks
ISO 3696:1987, Water for analytical laboratory use — Specification and test methods
3 Terms and definitions
For the purpose of this document, the following terms and definitions apply.
3.1
adsorbable organically bound halogens
AOX
equivalent amount of chlorine, bromine, and iodine contained in organic compounds, expressed as chloride
when determined according to this International Standard
ISO 9562:2004(E)
3.2
dissolved organic carbon
DOC
amount of organically bound carbon present in water originating from compounds passing through a
membrane filter of 0,45 µm pore size and including cyanate and thiocyanate
4 Interferences
4.1 High AOX values can result from the presence of active chlorine and of some inorganic bromine and
iodine compounds, irreversibly bound to activated carbon. Reactions of these oxidizing agents with organic
substances in the sample and with the activated carbon can be prevented by the addition of sodium sulfite,
immediately after sampling.
4.2 Organic bromine and iodine compounds may, during combustion, decompose to elemental bromine or
iodine respectively and this can yield higher oxidation states of these elements. These fractions of AOX may
be incompletely determined, thus leading to negative bias.
4.3 Samples containing living cells (for example microorganisms or algae) may give rise to high results
because of their chloride content. In these cases, the sample is not analysed until at least 8 h after
acidification.
4.4 For samples with high chloride concentrations (approximately 1 g/l), the shaking procedure (9.3.2) can
result in higher interferences than the column procedure (9.3.4).
4.5 Alcohols, aromatic compounds, or carboxylic acids may give rise to negative bias (e.g. in case of DOC
values > 100 mg/l).
4.6 For samples containing suspended solids, the stirring method (9.3.3) may lead to an insufficient
covering of the particles. If the particles contain substances contributing to the AOX, the shaking or column
method is recommended.
4.7 The recovery of some polar and hydrophilic compounds, such as monochloroacetic acid, is incomplete.
5 Principle
Acidification of the water sample with nitric acid. Adsorption of organic compounds contained in the sample
onto activated carbon, either by a shaking procedure, a stirring procedure, or by column adsorption.
Displacement of inorganic halides by rinsing the activated carbon with sodium nitrate solution acidified with
nitric acid. Combustion of the loaded carbon in an oxygen stream. Absorption of the hydrogen halides in an
acceptor solution followed by determination of the halide ions by an argentometric titration, such as
microcoulometry. Expression of the result as the mass concentration of chloride.
6 Reagents
Use only reagents of recognized analytical grade. The purity of water, reagents and gases shall be confirmed.
The AOX content shall be negligible when compared with the lowest AOX content to be determined. The
overall AOX content of water, chemicals and gases can be checked by measuring the total blank (10.2).
6.1 Water, Grade 1 as specified in ISO 3696:1987.
6.2 Activated carbon, the handling of which is given in Annex B, for one of three procedures listed in 6.2.1
to 6.2.3.
2 © ISO 2004 – All rights reserved

ISO 9562:2004(E)
Several methods may be applied to determine the adsorption capacity. One of these methods is described in
reference [1]. The iodine number gives an indication of the activated carbon adsorption capacity. According to
the method given in reference [1], the iodine numbers shall be > 1 050.
The blank value of the washed activated carbon shall be less than 15 µg of chloride equivalent per gram of
activated carbon.
6.2.1 Activated carbon for the shaking procedure, with a grain size of about 10 µm to 50 µm.
1)
6.2.2 Activated carbon fleeces for the stirring procedure, are commercially available .
6.2.3 Activated carbon for the column procedure, with a grain size of about 50 µm to 150 µm.
6.3 Nitric acid, HNO .
6.3.1 Nitric acid, concentrated, ρ(HNO ) = 1,4 g/ml, w(HNO ) = 65 %.
3 3
6.3.2 Nitric acid, dilute, c(HNO ) = 0,02 mol/l.
6.4 Hydrochloric acid, c(HCl) = 0,010 mol/l.
The molarity shall be known precisely, since the acid is used for checking the microtitration (9.5.1).
6.5 Sulfuric acid, H SO , ρ(H SO ) = 1,84 g/ml.
2 4 2 4
6.6 Gases for combustion, for example oxygen (O ), or a mixture of oxygen and an inert gas.
6.7 Nitrate, stock solution, c(NaNO ) = 0,2 mol/l.
Dissolve 17 g of sodium nitrate (NaNO ) in water (6.1) in a 1 000 ml volumetric flask, add 25 ml of
concentrated HNO (6.3.1), and make up to volume with water (6.1).
If stored in a brown glass bottle, the solution is stable for three months.
6.8 Nitrate washing solution, c(NaNO ) = 0,01 mol/l, pH ≈ 1,7.
Pipette 50 ml of the nitrate stock solution (6.7) in a 1 000 ml volumetric flask, and make up to volume with
water (6.1).
If stored in a brown glass bottle, the solution is stable for one month.
6.9 Sodium sulfite solution, c(Na SO ) = 1 mol/l.
2 3
Dissolve 126 g of Na SO in water (6.1) in a 1 000 ml volumetric flask and make up to volume with water (6.1).
2 3
The solution is stable for one month if stored at 2 °C to 8 °C.
6.10 4-Chlorophenol, stock solution, ρ (AOX) = 200 mg/l.
Cl
Dissolve 72,5 mg of 4-chlorophenol (C H ClO) in water (6.1) in a 100 ml volumetric flask and make up to
6 5
volume with water (6.1).
1) A suitable product available commercially can be obtained from Normenausschuss Wasserwesen (NAW) im DIN
Deutsches Institut für Normung e. V., 10772 Berlin. This information is given for the convenience of users of this
International Standard and does not constitute an endorsement by ISO of this product. Equivalent products may be used if
they can be shown to lead to the same results.
ISO 9562:2004(E)
For security reasons, it is advisable to use commercially available solutions.
This stock solution may be stored one month at 2 °C to 8 °C in a glass bottle.
6.11 4-Chlorophenol, working solution, ρ (AOX) = 1 mg/l.
Cl
Pipette 5 ml of 4-chlorophenol, stock solution (6.10), into a 1 000 ml volumetric flask, and make up to volume
with water (6.1).
This working solution may be stored one week at 2 °C to 8 °C in a glass bottle.
6.12 2-Chlorobenzoic acid, stock solution, ρ (AOX) = 250 mg/l.
Cl
Dissolve 110,4 mg of 2-chlorobenzoic acid (ClC H COOH) in water in a 100 ml volumetric flask and make up
6 4
to volume with water (6.1).
The dissolution of 2-chlorobenzoic acid is very slow. It is recommended to prepare this solution the day before
using it.
This stock solution may be stored for one month at 2 °C to 8 °C in a glass bottle.
6.13 2-Chlorobenzoic acid, working solution, ρ (AOX) = 1 mg/l.
Cl
Pipette 4 ml of 2-chlorobenzoic acid, stock solution (6.12), into a 1 000 ml volumetric flask, and make up to
volume with water (6.1).
This working solution may be stored 1 week at 2 °C to 8 °C in a glass bottle.
6.14 Standard solutions for the checks, on the overall procedure (9.5.2).
Pipette, for example, 1 ml, 5 ml, 10 ml, 20 ml, and 25 ml of the working solutions (6.11 or 6.13) into five
separate 100 ml volumetric flasks, and make up to volume with water (6.1).
The AOX mass concentration of these solutions is 10 µg/l, 50 µg/l, 100 µg/l, 200 µg/l and 250 µg/l respectively.
The concentration of the solutions should be chosen in such a way that the total working range is covered.
Prepare fresh standard solutions on the day of use.
6.15 Potassium iodide (KI).
6.16 Starch solution, having a mass fraction of 1 %.
7 Apparatus
7.1 Activated carbon adsorption apparatus.
7.1.1 Adsorption apparatus for the shaking procedure (9.3.2).
7.1.1.1 Filtration apparatus, for example with filter funnel of capacity of V = 0,15 l and filter diameter of
25 mm.
7.1.1.2 Polycarbonate membrane filter, for example with diameter of 25 mm and pore width of 0,45 µm
or equivalent filter material.
7.1.1.3 Conical flask, 250 ml, in accordance with ISO 1773.
4 © ISO 2004 – All rights reserved

ISO 9562:2004(E)
7.1.1.4 Mechanical shaking device for the flasks, specified in 7.1.1.3, for example with carrier plate.
7.1.2 Adsorption apparatus for the stirring method (9.3.3)
7.1.2.1 Conical flask, 100 ml, in accordance with ISO 1773.
7.1.2.2 Attachment device for the activated carbon fleece, e.g. coil, attached to the stopper.
7.1.2.3 Activated carbon fleece, for example round discs, 13 mm × 3 mm, activated carbon fibre (100 %
carbon), specific surface 1 600 m /g, mass 25 mg (for each measurement, two fleeces with a total mass of
50 mg of activated carbon are used).
7.1.2.4 Rinsing device, e.g. magnetic stirrer with cylindrical glass filter funnel for fixation of the activated
carbon fleece.
7.1.3 Adsorption apparatus for the column procedure (9.3.4).
Suitable pump, e.g. piston pump with polytetrafluoroethene (PTFE) tube and with adsorption tubes, inner
diameter about 3 mm, length 40 mm to 50 mm, attached vertically one behind the other. Other column
dimensions are acceptable. Each tube should be filled with about 50 mg of activated carbon. Add the sample
from the top of the column and transport it through the column using overpressure.
7.1.3.1 Ceramic wool, or equally suitable material, free from halogens, for fixation of the activated
carbon in the columns.
7.2 Apparatus for combustion and detection.
7.2.1 Combustion apparatus, consisting of a furnace, capable of being heated at least to 950 °C,
equipped with a quartz tube, with an inner diameter of 2 cm to 4 cm and length of about 30 cm (see example
Figure 1), of which both vertical and horizontal combustion tubes are common.
7.2.2 Quartz container, suitable for the quartz tube.
7.2.3 Argentometric measurement device, for determination of halide concentrations, usually
microcoulometer, suitable for the determination of 1 µg of chloride (absolute) with a coefficient of variation of
10 % (repeatability), or similar device (e.g. titration with a diluted AgNO solution) for the determination of
chloride ions.
7.2.4 Absorber, filled with sulfuric acid (6.5) for gas drying. The acid shall not backflush into the oven. The
acid shall be exchanged if its volume has increased by more than 20 %.
7.2.5 Syringe, suitable for pipetting 10 µl to 100 µl of hydrochloric acid (6.4).
7.3 Additional apparatus.
7.3.1 Measuring flask, 1 000 ml, e.g. ISO 1042 - A 1 000 - C.
7.3.2 Flat bottomed sampling bottles, preferably brown glass, 1 000 ml.
ISO 9562:2004(E)
Key
1 sample inlet for AOX
2 AOX sample
3 furnace
4 combustion tube
5 absorber filled with sulfuric acid (6.5)
6 titration cell
7 stirrer
8 control device for temperature, gas flow
9 combustion gas inlet
Figure 1 — Schematic diagram of an AOX apparatus (example)
8 Sampling and sample pre-treatment
Use glass or plastics vessels and an appropriate closure material such as polytetrafluoroethene (PTFE).
Verify that losses of organically bound halogens or contamination do not interfere.
Where lower concentrations of organic halogen compounds (e.g. if ρ (AOX) < 50 µg/l) are anticipated, glass
Cl
containers are preferable.
Collect the samples taking into account the particular properties of the matrix ensuring that no losses of the
target analytes occur.
If the samples are suspected of containing oxidizing agents, immediately add at the time of sampling up to
10 ml of sodium sulfite solution (6.9) per litre of sample.
To test samples for the presence of active chlorine before or after the addition of sodium sulfite (6.9), apply
the following procedure on a separate sample aliquot.
a) Transfer a few millilitres of the acidified sample into a test tube. Dissolve a few crystals of potassium
iodide (KI) (6.15) in the sample and add a few drops of a 1 % starch solution (6.16). A blue colour
indicates the presence of active chlorine. Other oxidants with sufficient oxidation potentials may give the
same reaction.
b) Add 2 ml of concentrated HNO (6.3.1) per litre of sample and completely fill the sample bottle leaving no
air gap, if necessary (see 4.3), allow the sample to stand for 8 h. Usually the quantity of the added acid is
sufficient to yield a pH < 2. It may be necessary to add more concentrated or dilute HNO (6.3.1 or 6.3.2)
to attain this pH.
6 © ISO 2004 – All rights reserved

ISO 9562:2004(E)
c) Analyse the water sample as soon as possible after sampling, or, in the presence of living cells (4.3) 8 h
after sampling. If this is not possible and storage is essential, store the acidified sample at 4 °C or deep
freeze it.
d) Prior to analysis, allow the sample to equilibrate to room temperature.
If volatile organic halogen compounds, for example chlorinated solvents, are expected, it is recommended to
start analysis within 24 h after sampling. A maximum storage time is not given since individual circumstances
will dictate the requirements.
9 Procedure
9.1 General
Prior to analysis, it is recommended to determine the limit of quantification from a blank measurement (10.2)
as a rough estimation. According to the result, the limit of determination may be equalized to the nine-fold
value of the standard deviation of the blank mean.
The test sample taken for analysis shall have a ρ (AO
...