EN ISO 16634-2:2016

SLOVENSKI STANDARD
01-september-2016
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SIST-TS CEN ISO/TS 16634-2:2010
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Food products - Determination of the total nitrogen content by combustion according to
the Dumas principle and calculation of the crude protein content - Part 2: Cereals, pulses
and milled cereal products (ISO 16634-2:2016)
Lebensmittelerzeugnisse - Bestimmung des Gehaltes an Gesamtstickstoff mit dem
Verbrennungsverfahren nach Dumas und Berechnung des Gehaltes an Rohprotein - Teil
2: Getreide, Hülsenfrüchte und gemahlene Getreideerzeugnisse (ISO 16634-2:2016)
Produits alimentaires - Détermination de la teneur en azote total par combustion selon le
principe Dumas et calcul de la teneur en protéines brutes - Partie 2: Céréales,
légumineuses et produits céréaliers de mouture (ISO 16634-2:2016)
Ta slovenski standard je istoveten z: EN ISO 16634-2:2016
ICS:
67.050 Splošne preskusne in General methods of tests and
analizne metode za živilske analysis for food products
proizvode
67.060 äLWDVWURþQLFHLQSURL]YRGLL] Cereals, pulses and derived
QMLK products
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 16634-2
EUROPEAN STANDARD
NORME EUROPÉENNE
June 2016
EUROPÄISCHE NORM
ICS 67.060; 67.050 Supersedes CEN ISO/TS 16634-2:2009
English Version
Food products - Determination of the total nitrogen
content by combustion according to the Dumas principle
and calculation of the crude protein content - Part 2:
Cereals, pulses and milled cereal products (ISO 16634-
2:2016)
Produits alimentaires - Détermination de la teneur en Lebensmittelerzeugnisse - Bestimmung des Gehaltes
azote total par combustion selon le principe Dumas et an Gesamtstickstoff mit dem Verbrennungsverfahren
calcul de la teneur en protéines brutes - Partie 2: nach Dumas und Berechnung des Gehaltes an
Céréales, légumineuses et produits céréaliers de Rohprotein - Teil 2: Getreide, Hülsenfrüchte und
mouture (ISO 16634-2:2016) gemahlene Getreideerzeugnisse (ISO 16634-2:2016)
This European Standard was approved by CEN on 12 May 2016.

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 CEN-CENELEC Management Centre 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 CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2016 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 16634-2:2016 E
worldwide for CEN national Members.

Contents Page
European Foreword . 3

European Foreword
This document (EN ISO 16634-2:2016) has been prepared by Technical Committee ISO/TC 34 "Food
products" in collaboration with Technical Committee CEN/TC 338 “Cereal and cereal products” the
secretariat of which is held by AFNOR.
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 December 2016, and conflicting national standards
shall be withdrawn at the latest by December 2016.
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 document supersedes CEN ISO/TS 16634-2:2009.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta,
Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.
Endorsement notice
The text of ISO 16634-2:2016 has been approved by CEN as EN ISO 16634-2:2016 without any
modification.
INTERNATIONAL ISO
STANDARD 16634-2
First edition
2016-05-15
Food products — Determination of the
total nitrogen content by combustion
according to the Dumas principle
and calculation of the crude protein
content —
Part 2:
Cereals, pulses and milled cereal
products
Produits alimentaires — Détermination de la teneur en azote total
par combustion selon le principe Dumas et calcul de la teneur en
protéines brutes —
Partie 2: Céréales, légumineuses et produits céréaliers de mouture
Reference number
ISO 16634-2:2016(E)
©
ISO 2016
ISO 16634-2:2016(E)
© ISO 2016, Published in Switzerland
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form
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ii © ISO 2016 – All rights reserved

ISO 16634-2:2016(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 2
5 Reagents . 2
6 Apparatus . 3
7 Sampling . 3
8 Preparation of the test sample . 3
9 Procedure. 4
9.1 General . 4
9.2 Test portion . 4
9.3 Control of oxygen supply . 4
9.4 Calibration . 5
9.5 Determination . 5
9.6 Detection and data processing . 5
10 Calculation and expression of results . 6
10.1 Calculation . 6
10.1.1 Nitrogen content . 6
10.1.2 Crude protein content . 6
10.2 Expression of results . 6
11 Precision . 6
11.1 Interlaboratory tests . 6
11.2 Repeatability . 7
11.3 Reproducibility . 7
11.4 Critical difference. 7
11.4.1 Comparison of two groups of measurements in the same laboratory . 7
11.4.2 Comparison of two groups of measurements in two different laboratories . 8
11.5 Uncertainty . 8
12 Test report . 8
Annex A (informative) Flowchart for a basic Dumas apparatus . 9
Annex B (informative) Schematic diagrams of suitable types of Dumas apparatus .10
Annex C (informative) Equipment calibration .13
Annex D (informative) Results of interlaboratory tests .15
Bibliography .22
ISO 16634-2:2016(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
...