1、June 2009DEUTSCHE NORM English price group 10No part of this standard may be reproduced without prior permission ofDIN Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale for German Standards (DIN-Normen).ICS 65.080!$X8q“1532178www.di
2、n.deDDIN EN 15558Fertilizers Determination of nitric and ammoniacal nitrogen according to UlschEnglish version of DIN EN 15558:2009-06Dngemittel Bestimmung von Nitrat- und Ammoniumstickstoff nach UlschEnglische Fassung DIN EN 15558:2009-06SupersedesDIN CEN/TS 15558:2007-06www.beuth.deDocument compri
3、ses pages15DIN EN 15558:2009-06 2 National foreword This standard has been prepared by Technical Committee CEN/TC 260 “Fertilizers and liming materials” (Secretariat: DIN, Germany) under the mandate M/335. The responsible German body involved in its preparation was the Normenausschuss Lebensmittel u
4、nd landwirtschaftliche Produkte (Food and Agricultural Products Standards Committee), Technical Committee NA 057-03-02 AA Dngemittel. The method specified in this standard is based upon Regulation (EC) No 2003/2003 relating to fertilizers, Annex IV, method 2.2.1 (see Bibliography). Amendments This s
5、tandard differs from DIN CEN/TS 15558:2007-06 as follows: a) The standard has been editorially revised. b) Normative references have been updated. Previous editions DIN CEN/TS 15558: 2007-06 EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 15558 January 2009 ICS 65.080 Supersedes CEN/TS 15558:20
6、07English Version Fertilizers Determination of nitric and ammoniacal nitrogen according to Ulsch Engrais Dosage de lazote nitrique et ammoniacal selon Ulsch Dngemittel Bestimmung von Nitrat- und Ammoniumstickstoff nach Ulsch This European Standard was approved by CEN on 30 November 2008. CEN members
7、 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
8、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 s
9、ame status as the official 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,
10、Romania,Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: rue de Stassart, 36 B-1050 Brussels 2009 CEN All rights of exploitation in any form and by any means rese
11、rved worldwide for CEN national Members. Ref. No. EN 15558:2009: EEN 15558:2009 (E) 2 Contents 1 Scope 42 Normative references 43 Terms and definitions .44 Principle 45 Reagents .46 Apparatus .57 Sampling and sample preparation 108 Procedure 109 Calculation and expression of the result . 1110 Test r
12、eport . 12Bibliography . 13Foreword 3PageDIN EN 15558:2009-06 EN 15558:2009 (E) 3 Foreword This document (EN 15558:2009) 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 o
13、f 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 pa
14、tent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights. This document supersedes CEN/TS 15558:2007. This document has been prepared under a mandate given to CEN by the European Commission and the European Free Trade Association. According to the C
15、EN/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,
16、 Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. DIN EN 15558:2009-06 EN 15558:2009 (E) 4 1 Scope This European Standard specifies a method for the determination of nitrate and ammoniacal nitrogen with reductio
17、n 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
18、 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, Fert
19、ilizers 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)
20、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 o
21、f 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 reag
22、ents 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, (HCl) = 1,18 g/ml, with one volume of wat
23、er. DIN EN 15558:2009-06 EN 15558:2009 (E) 5 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 % H2SO4(mass concentration), ammonia free. 5.6 Powdered iron, reduced in hydrogen. The prescribed qu
24、antity 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 (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 sol
25、ution 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 d
26、rops) 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, for example pumice
27、stone, washed in hydrochloric acid and calcined. 5.10 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 eq
28、uipment 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. DIN EN 15558:2009-06 EN 15558:2009 (E) 6 Dimensions in millimet
29、res 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 poly
30、tetrafluoroethylene (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 (whe
31、n the connection to the distillation tube is effected by means of a rubber tube, thespherical 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 DIN EN 15558:2009-06 EN 15558:2009 (E) 7 Dimensions i
32、n millimetres Key 1 round-bottomed, short-necked flask of 1 000 ml capacity with a spherical joint (No 35) 2 distillation tube with a splash head, equipped with a spherical joint (No 35) at the entrance and a spherical joint (No 18) at the issue, connected at the side to a funnel with a polytetraflu
33、oroethylene (PTFE) tap (5) for the additionof sodium hydroxide 3 six-bulb condenser with a spherical joint (No 18) at the entrance and joined at the issue to a glass extension tube by means of a small rubber connection 4 500 ml flask in which the distillate is collected 5 PTFE-tap a enlarged descrip
34、tion Figure 2 Distillation apparatus 2 DIN EN 15558:2009-06 EN 15558:2009 (E) 8 Dimensions in millimetres Key 1 round-bottomed, long-necked flask of 750 ml or 1 000 ml capacity with, a bell mouth 2 distillation tube with a splash head and a spherical joint (No 18) at the issue 3 elbow tube with a sp
35、herical joint (No 18) at the entrance and a drip cone (the connection to the distillation tube may be effected by means of a rubber tube instead of a spherical joint) 4 six-bulb condenser joined at the issue to a glass extension tube by means of a small rubber connection 5 500 ml flask in which the
36、distillate is collected Figure 3 Distillation apparatus 3 DIN EN 15558:2009-06 EN 15558:2009 (E) 9 Dimensions in millimetres Key 1 round-bottomed, long-necked flask of 1 000 ml capacity with a bell mouth 2 distillation tube with a splash head and a spherical joint (No 18), at the issue, connected at
37、 the side to a funnel with a polytetrafluoroethylene (PTFE) tap (5) for the addition of sodium hydroxide (a suitable rubber bung may be usedinstead of the spherical joint; the tap may be replaced by a rubber connection with an appropriate clip) 3 six-bulb condenser with a spherical joint (No 18) at
38、the entrance, joined at the issue, by a rubber connection, to a glass extension tube (when the connection to the distillation tube is effected by means of a rubber tube, the sphericaljoint may be replaced by a suitable rubber bung) 4 500 ml flask for the collection of the distillate 5 PTFE-tap Figur
39、e 4 Distillation apparatus 4 DIN EN 15558:2009-06 EN 15558:2009 (E) 10 6.2 Pipettes, of capacity 10 ml, 20 ml, 25 ml, 50 ml, 100 ml and 200 ml. 6.3 Graduated flasks, of capacity 500 ml. 6.4 Rotary shaker, 35 to 40 turns per minute. 7 Sampling and sample preparation Sampling is not part of the method
40、 specified in this Technical Specification. A recommended sampling method is given in EN 1482-1. Sample preparation shall be carried out in accordance with EN 1482-2. 8 Procedure 8.1 Preparation of the solution 8.1.1 General Carry out a solubility test on the sample in water at room temperature and
41、in the proportion of 2 % (mass concentration). Weigh to 0,001 g, according to the indications given in Table 1, a quantity of 5 g or 7 g or 10 g of the prepared sample and place it in a 500 ml graduated flask. According to the result of the solubility test, proceed as follows: 8.1.2 Products complet
42、ely soluble in water Add to the flask the quantity of water needed to dissolve the sample; shake, and when completely dissolved, make up the volume and mix thoroughly. 8.1.3 Products not completely soluble in water Add to the flask 50 ml of water and then 20 ml of hydrochloric acid (5.2). Shake and
43、leave undisturbed until the evolution of carbon dioxide has ceased. Add 400 ml of water and shake for half an hour with the rotary shaker (6.4). Make up the volume with water, mix and filter through a dry filter into a dry receptacle. 8.2 Procedure Place in the receiving flask an exactly measured qu
44、antity of 50 ml standard sulfuric acid and add the appropriate quantity of indicator solution 5.8.1 or 5.8.2. The end of the extension tube of the condenser shall be below the surface of the standard acid in the receiving flask. Using a precision pipette, transfer an aliquot part of the clear soluti
45、on as indicated in Table 1 and place it in the distillation flask of the apparatus. Add 350 ml of water, 20 ml of 30 % sulfuric acid solution (5.5) stir, and add 5 g of reduced iron (5.6). Wash the neck of the flask with several millilitres of water, and place in the neck of the flask a small, long-
46、stemmed funnel. Heat in a boiling water bath for an hour and then wash the stem of the funnel with a few millilitres of water. Taking care to avoid any loss of ammonia, add to the contents of the distillation flask 50 ml of concentrated sodium hydroxide solution (5.7), or in the cases where 20 ml of
47、 hydrochloric acid (5.2) has been used to dissolve the sample, add 60 ml of concentrated sodium hydroxide solution (5.7). Assemble the distillation apparatus. Gradually warm the flask, to avoid boiling vigorously. When boiling commences, distil at the rate of about 100 ml in 10 min to 15 min; the to
48、tal volume of distillate should be about 250 ml. The condenser shall be regulated in such a way that a continuous flow of condensate is ensured. The distillation should be completed DIN EN 15558:2009-06 EN 15558:2009 (E) 11 in 30 min to 40 min. When no more ammonia is likely to be evolved, lower the
49、 receiving flask so that the tip of the condenser extension is above the surface of the liquid. Test the subsequent distillate by means of an appropriate reagent to ensure that all the ammonia is completely distilled. Wash the condenser extension with a little water and titrate the surplus acid with the standard solution of sodium or potassium hydroxide prescribed for the variant adopted (see NOTE). NOTE Standard solutions of different strengths may be used for the back titration provided that the volum
