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STANDARDSIST-TS CEN/TS 15559:20081DGRPHãþD
SIST EN 15559:2009
EUROPEAN STANDARDNORME EUROPÉENNEEUROPÄISCHE NORMEN 15559January 2009ICS 65.080Supersedes CEN/TS 15559:2007
English VersionFertilizers - Determination of nitric and ammoniacal nitrogenaccording to ArndEngrais - Dosage de l'azote nitrique et ammoniacal selonArndDüngemittel - Bestimmung von Nitrat- undAmmoniumstickstoff nach ArndThis European Standard was approved by CEN on 6 December 2008.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nationalstandards may be obtained on application to the CEN 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 translationunder the responsibility of a CEN member into its own language and notified to the CEN Management Centre has the same status as theofficial versions.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 STANDARDIZATIONCOMITÉ EUROPÉEN DE NORMALISATIONEUROPÄISCHES KOMITEE FÜR NORMUNGManagement Centre: rue de Stassart, 36
B-1050 Brussels© 2009 CENAll rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN 15559:2009: ESIST EN 15559:2009
EN 15559:2009 (E) 2 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
SIST EN 15559:2009
EN 15559:2009 (E) 3 Foreword This document (EN 15559:2009) has been prepared by Technical Committee CEN/TC 260 “Fertilizers and liming materials”, the secretariat of 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 July 2009, and conflicting national standards shall be withdrawn at the latest by July 2009. 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/TS 15559:2007. 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 implement this European Standard: 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.
SIST EN 15559:2009
EN 15559:2009 (E) 4 1 Scope This European Standard 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. SIST EN 15559:2009
EN 15559:2009 (E) 5 5.3 Sulfuric acid (for variant a), c = 0,05 mol/l. 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 (MgCl2.6H2O) in approximately 600 ml to 700 ml of water in a 1 l flat-bottomed flask. To prevent frothing, add 15 g of magnesium sulfate (MgSO4.7H2O). 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. 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, for example pumice stone, washed in hydrochloric acid and reclaimed. SIST EN 15559:2009
EN 15559:2009 (E) 6
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. SIST EN 15559:2009
EN 15559:2009 (E) 7 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 rubbe
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