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!$X8l“1532173www.di
2、n.deDDIN EN 15560Fertilizers Determination of total nitrogen in calcium cyanamide nitrate freeEnglish version of DIN EN 15560:2009-06Dngemittel Bestimmung von Gesamtstickstoff in nitratfreiem KalkstickstoffEnglische Fassung DIN EN 15560:2009-06SupersedesDIN CEN/TS 15560:2007-07www.beuth.deDocument c
3、omprises pages16DIN EN 15560:2009-06 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 Lebensmit
4、tel und 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 2.3.1 (see Bibliography). Amendments T
5、his standard differs from DIN CEN/TS 15560:2007-07 as follows: a) The standard has been editorially revised. b) Normative references have been updated. Previous editions DIN CEN/TS 15560: 2007-07 EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 15560 January 2009 ICS 65.080 Supersedes CEN/TS 155
6、60:2007English Version Fertilizers Determination of total nitrogen in calcium cyanamide nitrate free Engrais Dosage de lazote total dans la cyanamide calcique exempte de nitrate Dngemittel Bestimmung von Gesamtstickstoff in nitratfreiem Kalkstickstoff This European Standard was approved by CEN on 6
7、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 national standards may be
8、 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 Ma
9、nagement 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, No
10、rway, Poland, Portugal, 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 fo
11、rm and by any means reserved worldwide for CEN national Members. Ref. No. EN 15560:2009: EEN 15560:2009 (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 .5 7 Sampling and sample preparation 10 8 Procedure 10 9 Calcul
12、ation and expression of the result . 12 10 Test report . 13 Bibliography . 14 DIN EN 15560:2009-06 EN 15560:2009 (E) 3 Foreword This document (EN 15560:2009) has been prepared by Technical Committee CEN/TC 260 “Fertilizers and liming materials”, the secretariat of which is held by DIN. This European
13、 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 t
14、his 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 15560:2007. This document has been prepared under a mandate given to CEN by the European Commission and the European Free
15、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, Icelan
16、d, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. DIN EN 15560:2009-06 EN 15560:2009 (E) 4 1 Scope This European Standard specifies a method for the determination of total ni
17、trogen in nitrate-free calcium cyanamide. 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 amend
18、ments) 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
19、 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 Digestion i
20、n sulfuric acid with the aid of a catalyst. Distillation of the ammonia from an alkaline solution, absorption in an excess of standard sulfuric acid solution and back-titration with standard sodium or potassium hydroxide solution. 5 Reagents 5.1 General Use only reagents of recognized analytical gra
21、de and distilled or demineralized water, free from carbon dioxide and all nitrogenous compounds (grade 3 according to EN ISO 3696:1995). 5.2 Diluted sulfuric acid, mix one volume of sulfuric acid, = 1,84 g/ml, with one volume of water. 5.3 Potassium sulphate, p.a. 5.4 Catalyst Use 0,3 g to 0,4 g of
22、copper(II)oxide or 0,95 g to 1,25 g of copper(II)sulfate pentahydrate for each determination. DIN EN 15560:2009-06 EN 15560:2009 (E) 5 5.5 Sodium hydroxide solution, 30 % mass concentration, of approximately (NaOH) = 1,33 g/ml, ammonia free 5.6 Sulfuric acid, c = 0,05 mol/l. 5.7 Sodium or potassium
23、hydroxide solution, carbonate free, c = 0,1 mol/l. 5.8 Sulfuric acid, c = 0,1 mol/l. 5.9 Sodium or potassium hydroxide solution, carbonate free, c = 0,2 mol/l. 5.10 Sulfuric acid, c = 0,25 mol/l. 5.11 Sodium or potassium hydroxide solution, carbonate free, c = 0,5 mol/l. 5.12 Indicator solutions 5.1
24、2.1 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
25、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
26、 to 5 drops) instead of that specified in 5.12.1. 5.13 Anti-bump granules of pumice stone, washed in hydrochloric acid and calcined. 5.14 Potassium thiocyanate, p.a. 6 Apparatus 6.1 Distillation apparatus Consisting of a round-bottomed flask of suitable capacity connected to a condenser by means of
27、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
28、 statistically equivalent. DIN EN 15560:2009-06 EN 15560:2009 (E) 6 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
29、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, a
30、nd 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, thespherical joint may be replaced by a suitable rubber bung) 5 500 ml flask in which the distillate is collected 6 PTFE-tap a h
31、ole Figure 1 Distillation apparatus 1 DIN EN 15560:2009-06 EN 15560:2009 (E) 7 Dimensions in 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
32、spherical joint (No 18) at the issue, connected at the side to a funnel with a polytetrafluoroethylene (PTFE) tap (5) for the addition of 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
33、connection 4 500 ml flask in which the distillate is collected 5 PTFE-tap a enlarged description Figure 2 Distillation apparatus 2 DIN EN 15560:2009-06 EN 15560:2009 (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 distillati
34、on tube with a splash head and a spherical joint (No 18) at the issue 3 elbow tube with a spherical 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
35、to a glass extension tube by means of a small rubber connection 5 500 ml flask in which the distillate is collected Figure 3 Distillation apparatus 3 DIN EN 15560:2009-06 EN 15560:2009 (E) 9 Dimensions in millimetres Key 1 round-bottomed, long-necked flask of 1 000 ml capacity with a bell mouth 2 di
36、stillation tube with a splash head and a spherical joint (No 18), at the issue, connected at the side to a funnel with a polytetrafluoroethylene (PTFE) tap (5) for the addition of sodium hydroxide (a suitable rubber bung may be used instead of the spherical joint; the tap may be replaced by a rubber
37、 connection with an appropriate clip) 3 six-bulb condenser with a spherical joint (No 18) at 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
38、 a suitable rubber bung) 4 500 ml flask for the collection of the distillate 5 PTFE-tap Figure 4 Distillation apparatus 4 DIN EN 15560:2009-06 EN 15560:2009 (E) 10 6.2 Kjeldahl flask, long necked and of suitable capacity. 6.3 Pipettes, of capacity 50 ml, 100 ml and 200 ml. 6.4 Graduated flask, of ca
39、pacity 250 ml. 7 Sampling and sample preparation Sampling is not part of the method 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 Weigh,
40、 to the nearest 0,001 g, 1 g of the sample and place it in the Kjeldahl flask. Add 50 ml of diluted sulfuric acid (5.2), 10 g to 15 g of potassium sulfate (5.3) and the appropriate amount of catalyst (5.4). Heat slowly to drive off the water, boil gently for 2 h, allow to cool and dilute with 100 ml
41、 to 150 ml of water. Cool again, transfer quantitatively the suspension to a graduated 250 ml flask, and make up the volume with water, shake and filter through a dry filter into a dry flask. 8.2 Analysis of the solution According to the variant chosen, place in the receiving flask a measured quanti
42、ty of standard sulfuric acid as indicated in Table 1, Table 2 or Table 3. Add the appropriate quantity of the chosen indicator solution (5.12.1 or 5.12.2) and, if necessary, water in order to obtain a volume of at least 50 ml. The end of the extension tube of the condenser shall be below the surface
43、 of the solution. With a pipette, transfer, according to the variant chosen, 50 ml, 100 ml or 200 ml of the solution obtained as described in 8.1, and distil the ammonia as described below, adding sufficient NaOH solution (5.5) to ensure a considerable excess. Add water in order to obtain a total vo
44、lume of about 350 ml and several grains of pumice in order to control the boiling. Assemble the distillation apparatus, and taking care to avoid any loss of ammonia, add to the contents of the distillation flask 10 ml of concentrated sodium hydroxide solution (5.5). Gradually warm the flask, to avoi
45、d boiling vigorously. When boiling commences, distil at the rate of about 100 ml in 10 min to 15 min; the total volume of distillate should be about 250 ml. The condenser shall be regulated so that a continuous flow of condensate is ensured. The distillation should be completed in 30 min to 40 min.
46、When no more ammonia is likely to be evolved, lower the 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 extensio
47、n 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 volumes used for the titration do not, as
48、far as possible, exceed 45 ml. DIN EN 15560:2009-06 EN 15560:2009 (E) 11 Table 1 Weighing, dilution and calculation variant a Declaration % N Amount to be weighed g Dilution ml Solution of sample to be distilled ml Expression of the result a% N = (50 A) F 0 to 5 5 to 10 10 to 15 15 to 20 20 to 40 10
49、 10 7 5 7 500 500 500 500 500 50 25 25 25 10 (50 A) 0,14 (50 A) 0,28 (50 A) 0,40 (50 A) 0,56 (50 A) 1,00 Approximate maximum quantity of nitrogen to be distilled: 50 mg. Sulfuric acid 0,05 mol/l to be placed in the receiving flask: 50 ml. Back titration with NaOH or KOH 0,1 mol/l. aFor the purposes of the equation for expression of the result: 50 = volume of standard solution of sulfuric acid to be placed in the receiving flask, in millilitres; A = volume of sodium or potassium hydroxide used for the back titration,
