SIST-TS CEN/TS 15559:2008
(Main)Fertilizers - Determination of nitric and ammoniacal nitrogen according to Arnd
Fertilizers - Determination of nitric and ammoniacal nitrogen according to Arnd
This Technical Specification specifies a method for the determination of nitric and ammoniacal nitrogen with reduction according to Arnd (modified for each of the variants a, b and c).
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 Arnd
Engrais - Détermination de l'azote nitrique et ammoniacal selon Arnd
La présente Spécification technique spécifie une méthode de dosage de l’azote nitrique et ammoniacal, avec réduction, selon Arnd (modifiée pour chacune des variantes a, b et c).
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.
Gnojila - Določevanje nitratnega in amonijevega dušika po Arndu
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
SIST-TS CEN/TS 15559:2008
01-marec-2008
*QRMLOD'RORþHYDQMHQLWUDWQHJDLQDPRQLMHYHJDGXãLNDSR$UQGX
Fertilizers - Determination of nitric and ammoniacal nitrogen according to Arnd
Düngemittel - Bestimmung von Nitrat- und Ammoniumstickstoff nach Arnd
Engrais - Détermination de l'azote nitrique et ammoniacal selon Arnd
Ta slovenski standard je istoveten z: CEN/TS 15559:2007
ICS:
65.080
SIST-TS CEN/TS 15559:2008 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 15559
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 Arnd
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 15559:2007: E
worldwide for CEN national Members.
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CEN/TS 15559:2007 (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 .14
10 Test report .14
Bibliography .15
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CEN/TS 15559:2007 (E)
Foreword
This document (CEN/TS 15559:2007) 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.
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CEN/TS 15559:2007 (E)
1 Scope
This Technical Specification specifies a method for the determination of nitric and ammoniacal nitrogen with
reduction according to Arnd (modified for each of the variants a, b and c).
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 in a neutral aqueous solution by means of a metallic alloy
composed of 60 % Cu and 40 % Mg (Arnd’s alloy) in the presence of magnesium chloride.
Distillation of the ammonia and determination of the yield in a known volume of standard sulfuric acid solution.
Titration of the excess 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.
5.3 Sulfuric acid (for variant a)
c = 0,05 mol/l
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CEN/TS 15559:2007 (E)
5.4 Sodium or potassium hydroxide solution (for variant a)
carbonate free, c = 0,1 mol/l
5.5 Sulfuric acid (for variant b, see NOTES in 8.2)
c = 0,1 mol/l
5.6 Sodium or potassium hydroxide solution (for variant b, see NOTES in 8.2)
carbonate free, c = 0,2 mol/l
5.7 Sulfuric acid (for variant c, see NOTES in 8.2)
c = 0,25 mol/l
5.8 Sodium or potassium hydroxide solution (for variant c, see NOTES in 8.2)
carbonate free, c = 0,5 mol/l
5.9 Sodium hydroxide solution
approximately c = 2 mol/l
5.10 Arnd’s alloy
powdered so as to pass through a sieve with apertures less than 1 mm square
5.11 Magnesium chloride solution, 20 %
.
Dissolve 200 g of magnesium chloride (MgCl 6H O) in approximately 600 ml to 700 ml of water in a 1 l flat-
2 2
bottomed flask. To prevent frothing, add 15 g of magnesium sulfate (MgSO .7H O).
4 2
After dissolution add 2 g of magnesium oxide and a few anti-bump granules of pumice stone and concentrate
the suspension to 200 ml by boiling, thus expelling any trace of ammonia from the reagents. Cool, make up
the volume to 1 l and filter.
5.12 Indicator solutions
5.12.1 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.
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CEN/TS 15559:2007 (E)
5.12.2 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 5.12.1.
5.12.3 Congo red indicator solution
Dissolve 3 g of Congo red in 1 l of warm water and filter if necessary after cooling. This indicator may be used,
instead of that specified in 5.12.1.or 5.12.2, in the neutralization of acid extracts before distillation, using
0,5 ml per 100 ml of liquid to be neutralized.
5.13 Anti-bump granules of pumice stone
washed in hydrochloric acid and reclaimed
5.14 Sodium nitrate
p.a.
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.
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CEN/TS 15559:2007 (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)
3 funnel with a polytetrafluoroethylene (PTFE) tap (6) for the addition of sodium hydroxide (the tap may
likewise be replaced by a rubber connection with a clip)
4 six-bulb condenser with spherical joint (No 18) at the entrance, and joined at the issue to a glass
extension tube by means of a small rubber connection (when the connection to the distillation tube is effected
by means of a rubber tube, the spherical joint may be replaced by a suitable rubber bung)
5 500 ml flask in which the distillate is collected
6 PTFE-tap
a
hole
Figure 1 — Distillation apparatus 1
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