SIST-TS CEN/TS 15558:2008

Fertilizers - Determination of nitric and ammoniacal nitrogen according to Ulsch

This Technical Specification specifies a method for the determination of nitrate and ammoniacal nitrogen with reduction according to Ulsch.
The method is applicable to all nitrogenous fertilizers, including compound fertilizers, in which nitrogen is found exclusively in nitrate form, or in ammoniacal and nitrate form.

Düngemittel - Bestimmung von Nitrat- und Ammoniumstickstoff nach Ulsch

Engrais - Détermination de l'azote nitrique et ammoniacal selon Ulsch

La présente Spécification technique spécifie une méthode de dosage de l’azote nitrique et ammoniacal, avec réduction, selon Ulsch.
La présente méthode est applicable a tous les engrais azotés, y compris les engrais composés ou l’azote se trouve exclusivement sous forme nitrique ou sous forme ammoniacale et nitrique.

Trdna gnojila - Določevanje nitratnega in amonijevega dušika po Ulschu

General Information

• Status: Withdrawn
• Publication Date: 12-Feb-2008
• Withdrawal Date: 11-May-2009
• ICS: 65.080 - Fertilizers
• Technical Committee: KAT - Soil quality
• Current Stage: 9900 - Withdrawal (Adopted Project)
• Start Date: 11-May-2009
• Due Date: 03-Jun-2009
• Completion Date: 12-May-2009
• Mandate: M/335 - Standardization Mandate assigned to the CEN concerning the modernisation of the methods of anylysis of Fertilizers
• Ref Project: CEN/TS 15558:2007 - Fertilizers - Determination of nitric and ammoniacal nitrogen according to Ulsch

Relations

• Replaced By: SIST EN 15558:2009 - Fertilizers - Determination of nitric and ammoniacal nitrogen according to Ulsch
• Effective Date: 01-Jun-2009

Standards Content (Sample)

SLOVENSKI STANDARD
SIST-TS CEN/TS 15558:2008
01-marec-2008
7UGQDJQRMLOD'RORþHYDQMHQLWUDWQHJDLQDPRQLMHYHJDGXãLNDSR8OVFKX
Fertilizers - Determination of nitric and ammoniacal nitrogen according to Ulsch
Düngemittel - Bestimmung von Nitrat- und Ammoniumstickstoff nach Ulsch
Engrais - Détermination de l'azote nitrique et ammoniacal selon Ulsch
Ta slovenski standard je istoveten z: CEN/TS 15558:2007
ICS:
65.080
SIST-TS CEN/TS 15558:2008 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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TECHNICAL SPECIFICATION
CEN/TS 15558
SPÉCIFICATION TECHNIQUE
TECHNISCHE SPEZIFIKATION
March 2007
ICS 65.080

English Version
Fertilizers - Determination of nitric and ammoniacal nitrogen
according to Ulsch
Engrais - Détermination de l'azote nitrique et ammoniacal Düngemittel - Bestimmung von Nitrat- und
selon Ulsch Ammoniumstickstoff nach Ulsch
This Technical Specification (CEN/TS) was approved by CEN on 1 January 2007 for provisional application.
The period of validity of this CEN/TS is limited initially to three years. After two years the members of CEN will be requested to submit their
comments, particularly on the question whether the CEN/TS can be converted into a European Standard.
CEN members are required to announce the existence of this CEN/TS in the same way as for an EN and to make the CEN/TS available
promptly at national level in an appropriate form. It is permissible to keep conflicting national standards in force (in parallel to the CEN/TS)
until the final decision about the possible conversion of the CEN/TS into an EN is reached.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, 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: rue de Stassart, 36  B-1050 Brussels
© 2007 CEN All rights of exploitation in any form and by any means reserved Ref. No. CEN/TS 15558:2007: E
worldwide for CEN national Members.

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CEN/TS 15558:2007 (E)
Contents Page
Foreword.3
1 Scope .4
2 Normative references .4
3 Terms and definitions .4
4 Principle.4
5 Reagents.4
6 Apparatus .6
7 Sampling and sample preparation.11
8 Procedure .11
9 Calculation and expression of the result .13
10 Test report .13
Bibliography .14

2

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CEN/TS 15558:2007 (E)
Foreword
This document (CEN/TS 15558:2007) has been prepared by Technical Committee CEN/TC 260 “Fertilizers
and liming materials”, the secretariat of which is held by DIN.
This document has been prepared under a mandate given to CEN by the European Commission and the
European Free Trade Association.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to announce this Technical Specification: Austria, Belgium, Bulgaria, 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 the United Kingdom.
3

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CEN/TS 15558:2007 (E)

1 Scope
This Technical Specification specifies a method for the determination of nitrate and ammoniacal nitrogen with
reduction according to Ulsch.
The method is applicable to all nitrogenous fertilizers, including compound fertilizers, in which nitrogen is
found exclusively in nitrate form, or in ammoniacal and nitrate form.
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.
EN 1482-2, Fertilizers and liming materials — Sampling and sample preparation — Part 2: Sample
preparation
EN 12944-1:1999, Fertilizers and liming materials and soil improvers — Vocabulary— Part 1: General terms
EN 12944-2:1999, Fertilizers and liming materials and soil improvers — Vocabulary— Part 2: Terms relating
to fertilizers
EN ISO 3696:1995, Water for analytical laboratory use — Specification and test methods (ISO 3696:1987)
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 12944-1:1999 and EN 12944-2:1999
apply.
4 Principle
Reduction of nitrates and nitrites to ammonia by means of metallic iron in an acid medium and displacement
of the ammonia thus formed by the addition of an excess of sodium hydroxide: distillation of the ammonia and
determination of the yield of ammonia in a known volume of standard sulfuric acid solution and titration of the
excess sulfuric acid by means of a standard solution of sodium or potassium hydroxide.
5 Reagents
5.1 General
Use only reagents of recognized analytical grade and distilled or demineralized water, free from carbon
dioxide and all nitrogenous compounds (grade 3 according to EN ISO 3696:1995).
5.2 Diluted hydrochloric acid
Mix one volume of concentrated hydrochloric acid solution, ρ(HCl) = 1,18 g/ml, with one volume of water.
4

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CEN/TS 15558:2007 (E)
5.3 Sulfuric acid
c = 0,05 mol/l
5.4 Sodium or potassium hydroxide solution
carbonate free, c = 0,1 mol/l
5.5 Sulfuric acid solution
approximately 30 % H SO (mass concentration), ammonia free
2 4
5.6 Powdered iron
Reduced in hydrogen (the prescribed quantity of iron shall be able to reduce at least 0,05 g of nitrate nitrogen)
5.7 Sodium hydroxide solution
30 % mass concentration, of approximately ρ(NaOH) = 1,33 g/ml, ammonia free
5.8 Indicator solutions
5.8.1 Mixed indicator
Solution A: Dissolve 1 g of methyl red in 37 ml of sodium hydroxide solution c = 0,1 mol/l and make up to 1 l
with water.
Solution B: Dissolve 1 g of methylene blue in water and make up to 1 l.
Mix one volume of solution A with two volumes of solution B.
This indicator is violet in acid solution, grey in neutral solution and green in alkaline solution. Use 0,5 ml
(10 drops) of this indicator solution.
5.8.2 Methyl red indicator solution
Dissolve 0,1 g of methyl red in 50 ml of 95 % ethanol. Make up to 100 ml with water and filter if necessary.
This indicator may be used (4 to 5 drops) instead of that specified in 5.8.1.
5.9 Anti-bump granules of pumice stone
washed in hydrochloric acid and calcined
5.10 Sodium nitrate
p. a.
5

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CEN/TS 15558:2007 (E)

6 Apparatus
6.1 Distillation apparatus
Consisting of a round-bottomed flask of suitable capacity connected to a condenser by means of a splash
head. The equipment is made of borosilicate glass.
NOTE The different types of equipment recommended for this determination are reproduced, showing all the features
of construction, in Figures 1, 2, 3 and 4.
An automatic distillation apparatus may also be used, provided that the results are statistically equivalent.
6

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CEN/TS 15558:2007 (E)
Dimensions in millimetres

Key
1 round-bottomed, long-necked flask of 1 000 ml capacity
2 distillation tube with a splash head, connected to the condenser by means of a spherical joint (No 18) (the
spherical joint for the connection to the condenser may be replaced by an appropriate rubber connection)
...