EN ISO 15681-2:2004

SLOVENSKI STANDARD
01-februar-2005
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Water quality - Determination of orthophosphate and total phosphorus contents by flow
analysis (FIA and CFA) - Part 2: Method by continuous flow analysis (CFA) (ISO 15681-
2:2003)
Wasserbeschaffenheit - Bestimmung von Othophosphat und Gesamtphosphor mittels
Fließanalytik (FIA und CFA) - Teil 2: Verfahren mittels kontinuierlicher Durchflussanalyse
(CFA) (ISO 15681-2:2003)
Qualité de l'eau - Dosage des orthophosphates et du phosphore total par analyse en flux
(FIA et CFA) - Partie 2: Méthode par analyse en flux continu (CFA) (ISO 15681-2:2003)
Ta slovenski standard je istoveten z: EN ISO 15681-2:2004
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 15681-2
NORME EUROPÉENNE
EUROPÄISCHE NORM
December 2004
ICS 13.060.50
English version
Water quality - Determination of orthophosphate and total
phosphorus contents by flow analysis (FIA and CFA) - Part 2:
Method by continuous flow analysis (CFA) (ISO 15681-2:2003)
Qualité de l'eau - Dosage des orthophosphates et du Wasserbeschaffenheit - Bestimmung von Othophosphat
phosphore total par analyse en flux (FIA et CFA) - Partie 2: und Gesamtphosphor mittels Fließanalytik (FIA und CFA) -
Méthode par analyse en flux continu (CFA) (ISO 15681- Teil 2: Verfahren mittels kontinuierlicher Durchflussanalyse
2:2003) (CFA) (ISO 15681-2:2003)
This European Standard was approved by CEN on 21 December 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,
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Slovenia, Spain, Sweden, Switzerland and United Kingdom.
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© 2004 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 15681-2:2004: E
worldwide for CEN national Members.

Foreword
The text of ISO 15681-2:2003 has been prepared by Technical Committee ISO/TC 147 "Water
quality” of the International Organization for Standardization (ISO) and has been taken over as
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 June 2005, and conflicting national
standards shall be withdrawn at the latest by June 2005.

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 15681-2:2003 has been approved by CEN as EN ISO 15681-2:2004 without any
modifications.
INTERNATIONAL ISO
STANDARD 15681-2
First edition
2003-12-15
Water quality — Determination of
orthophosphate and total phosphorus
contents by flow analysis (FIA and
CFA) —
Part 2:
Method by continuous flow analysis
(CFA)
Qualité de l'eau — Dosage des orthophosphates et du phosphore total
par analyse en flux (FIA et CFA) —
Partie 2: Méthode par analyse en flux continu (CFA)

Reference number
ISO 15681-2:2003(E)
©
ISO 2003
ISO 15681-2:2003(E)
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ii © ISO 2003 – All rights reserved

ISO 15681-2:2003(E)
Contents Page
Foreword. iv
Introduction . v
1 Scope. 1
2 Normative references. 1
3 Interferences. 2
3.1 General interferences. 2
3.2 Interferences in the determination of total-P . 2
4 Principle. 2
4.1 Determination of orthophosphate . 2
4.2 Total phosphorus with manual digestion. 3
4.3 Total phosphorus with integral UV digestion and hydrolysis. 3
5 Reagents. 3
6 Apparatus. 7
6.1 Continuous-flow analysis (CFA). 7
6.2 Additional apparatus. 7
6.3 Additional apparatus for the determination of total phosphorus after integral digestion . 8
7 Sampling and sample preparation . 8
8 Procedure. 8
8.1 Preparation for analysis . 8
8.2 Instrument performance check. 8
8.3 Reagent blank check . 9
8.4 Calibration. 9
8.5 Check of UV digestion and hydrolysis for total P determination (see Figure A.2). 9
8.6 Measurement. 10
8.7 Closing down the system. 10
9 Calculation of results. 10
10 Expression of results. 10
11 Test report. 10
Annex A (informative) Examples of a CFA system . 12
Annex B (informative) Precision and accuracy . 14
Annex C (informative) Determination of orthophosphate-P and total-P by CFA and tin(II) chloride
reduction. 15
Bibliography . 16

ISO 15681-2:2003(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 15681-2 was prepared by Technical Committee ISO/TC 147, Water quality, Subcommittee SC 2, Physical,
chemical and biochemical methods.
ISO 15681 consists of the following parts, under the general title Water quality — Determination of
orthophosphate and total phosphorus contents by flow analysis (FIA and CFA):
— Part 1: Method by flow injection analysis (FIA)
— Part 2: Method by continuous flow analysis (CFA)
iv © ISO 2003 – All rights reserved

ISO 15681-2:2003(E)
Introduction
Methods of determining water quality using flow analysis automated wet chemical procedures and are
particularly suitable for the processing of many analytes in water in large sample series at a high analysis
frequency.
[1], [2] [3]
Analysis can be performed by flow injection analysis (FIA) or continuous flow analysis (CFA) . Both
methods share the feature of an automatic dosage of the sample into a flow system (manifold) where the
analyte in the sample reacts with the reagent solutions on its way through the manifold. The sample
preparation may be integrated in the manifold. The amount of reaction product is measured in a flow detector
(e.g. flow photometer). This part of ISO 15681 describes the CFA method.
The user should be aware that particular problems could require the specification of additional marginal
conditions.
INTERNATIONAL STANDARD ISO 15681-2:2003(E)

Water quality — Determination of orthophosphate and total
phosphorus contents by flow analysis (FIA and CFA) —
Part 2:
Method by continuous flow analysis (CFA)
WARNING — Persons using this part of ISO 15681 should be familiar with normal laboratory practice.
This part of ISO 15681 does not purport to address all o
...