ISO 21793:2020

FINAL
INTERNATIONAL ISO/FDIS
DRAFT
STANDARD 21793
ISO/TC 147/SC 2
Water quality — Determination
Secretariat: DIN
of total organic carbon (TOC),
Voting begins on:
2020­03­10 dissolved organic carbon (DOC), total
bound nitrogen (TN ), dissolved
Voting terminates on:
b
2020­05­05
bound nitrogen (DN ), total bound
b
phosphorus (TP ) and dissolved
b
bound phosphorus (DP ) after wet
b
chemical catalysed ozone hydroxyl
radical oxidation (COHR)
Qualité de l'eau — Détermination du carbon organique total (COT),
du carbone organique dissous (COD), de l'azote total lié (TNb), de
l'azote dissous lié (DNb), du phosphore total lié et du phosphore
dissous lié (DPb) après oxydation par l'ozone avec des radicaus
hydroxyles et catalyseur en milieus aqueux
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Reference number
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO­
ISO/FDIS 21793:2020(E)
LOGICAL, COMMERCIAL AND USER PURPOSES,
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©
NATIONAL REGULATIONS. ISO 2020

ISO/FDIS 21793:2020(E)
© ISO 2020
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ii © ISO 2020 – All rights reserved

ISO/FDIS 21793:2020(E)
Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 2
5 Interferences . 3
5.1 General . 3
5.2 TOC . 3
5.3 TN . 3
5.4 TP . 4
6 Reagents . 4
7 Solution preparations . 5
7.1 Blank solution . 5
7.2 Sample oxidation solutions . 5
7.2.1 Sulfuric acid TIC and catalyst solution . 5
7.2.2 Base oxidation solution . 5
7.2.3 TP solution . 5
7.2.4 TP hydrolysis solution . 5
7.3 Calibration stock solutions . 6
7.4 Individual calibration standard solutions . 6
7.4.1 TOC . 6
7.4.2 TN . . 6
7.4.3 TP . 7
7.4.4 Combined calibration standard solutions . 7
7.5 System check stock solutions . 7
7.5.1 TOC and TN stock solution . 7
7.5.2 TP stock solution . 7
7.6 Particle processing control solution . 7
7.7 Gases . 8
8 Apparatus . 8
9 Quality requirements for the analytical system . 8
9.1 System check . 8
9.2 Recovery and variation of replicate determinations for particle processing control
for TOC, TN , and TP . 9
b b
10 Sampling and sample preparation . 9
10.1 Sampling and sample injection . 9
11 Procedure. 9
11.1 General . 9
11.2 Calibration .10
11.3 Validity check of the calibration function .10
11.4 Measurement .10
11.4.1 General.10
11.4.2 Determination .10
12 Evaluation .11
13 Expression of results .11
14 Test report .11
ISO/FDIS 21793:2020(E)
Annex A (normative) Determination of total organic carbon that includes purgeable
organic carbon by difference .13
Annex B (informative) Performance data TOC/TN .15
Annex C (informative) Informative validation data, system check recovery and particle
check recovery for TOC/TN/TP .17
Bibliography .31
iv © ISO 2020 – All rights reserved

ISO/FDIS 21793:2020(E)
Foreword
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This document was prepared by Technical Committee ISO/TC 147, Water quality, Subcommittee SC 2,
Physical, chemical and biochemical methods.
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