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!$X8r“1532179www.di
2、n.deDDIN EN 15561Fertilizers Determination of total nitrogen in calcium cyanamide containing nitratesEnglish version of DIN EN 15561:2009-06Dngemittel Bestimmung von Gesamtstickstoff in nitrathaltigem KalkstickstoffEnglische Fassung DIN EN 15561:2009-06SupersedesDIN CEN/TS 15561:2007-07www.beuth.deD
3、ocument comprises pages17DIN EN 15561:2009-06 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
4、Lebensmittel 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 2.3.2. Amendments This standa
5、rd differs from DIN CEN/TS 15561:2007-07 as follows: a) (German version only) In clause 4, 1stsentence, “Zinn(II)chloride” has been replaced by “Zinnchlorid-lsung”. b) Subclause 5.12 has been editorially revised; the NOTE has been changed to normative text. c) In subclause 5.12, the iodine solution
6、has been corrected to read 0,05 mol/l (instead of 0,1 mol/l). d) The standard has been editorially revised. e) Normative references have been updated. Previous editions DIN CEN/TS 15561: 2007-07 EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 15561 January 2009 ICS 65.080 Supersedes CEN/TS 1556
7、1:2007English Version Fertilizers Determination of total nitrogen in calcium cyanamide containing nitrates Engrais Dosage de lazote total dans la cyanamide calcique nitrate Dngemittel Bestimmung von Gesamtstickstoff in nitrathaltigem Kalkstickstoff This European Standard was approved by CEN on 6 Dec
8、ember 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 ob
9、tained 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 Manag
10、ement Centre has the same 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, Norw
11、ay, 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 form
12、 and by any means reserved worldwide for CEN national Members. Ref. No. EN 15561:2009: EEN 15561:2009 (E) 2 Contents Page Foreword 3 Scope 4 2Normative references 4 3Terms and definitions .4 4Principle 4 5Reagents .4 6Apparatus .6 7Sampling and sample preparation 11 8Procedure 11 9Calculation and ex
13、pression of the result . 13 10 Test report . 14 Bibliography . 15 DIN EN 15561:2009-06 EN 15561:2009 (E) 3 Foreword This document (EN 15561:2009) has been prepared by Technical Committee CEN/TC 260 “Fertilizers and liming materials”, the secretariat of which is held by DIN. This European Standard sh
14、all 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
15、 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 15561:2007. This document has been prepared under a mandate given to CEN by the European Commission and the European Free Trade Associ
16、ation. 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,
17、Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. DIN EN 15561:2009-06 EN 15561:2009 (E) 4 1 Scope This European Standard specifies a method for the determination of total nitrogen in ca
18、lcium cyanamide. The method is applicable to calcium cyanamide containing nitrates. 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 th
19、e 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 limi
20、ng 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 1
21、2944-2:1999 apply. 4 Principle Reduction of nitrate nitrogen to ammonia with metallic iron and stannous chloride solution. Digestion in sulfuric acid. Distillation of the ammonia from an alkaline solution, absorption in an excess of standard sulfuric acid solution and back-titration with standard so
22、dium or potassium hydroxide solution. 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 Sulfuric acid, = 1,84 g/ml. 5.3 Powdered iron, reduc
23、ed in hydrogen. 5.4 Potassium sulfate, p.a., finely pulverized. 5.5 Sulfuric acid (for variant a), c = 0,05 mol/l. DIN EN 15561:2009-06 EN 15561:2009 (E) 5 5.6 Sodium or potassium hydroxide standard solution (for variant a), carbonate free, c = 0,1 mol/l. 5.7 Sulfuric acid (for variant b, see NOTE i
24、n 8.2), c = 0,1 mol/l. 5.8 Sodium or potassium hydroxide standard solution (for variant b, see NOTE in 8.2), carbonate free, c = 0,2 mol/l. 5.9 Sulfuric acid (for variant c, see NOTE in 8.2), c = 0,25 mol/l. 5.10 Sodium or potassium hydroxide standard solution (for variant c, see NOTE in 8.2), carbo
25、nate free, c = 0,5 mol/l. 5.11 Indicator solutions 5.11.1 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 wit
26、h 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. 5.11.2 Methyl red indicator solution Dissolve 0,1 g of methyl red in 50 ml of 95 % ethanol. Make up to 100 ml with water
27、and filter if necessary. This indicator may be used (4 to 5 drops) instead of that specified in 5.11.1. 5.12 Stannous chloride solution Dissolve 120 g of SnCl22H2O in 400 ml of concentrated hydrochloric acid (20= 1,18 g/ml) and make up to 1 l with water. The solution shall be completely clear and pr
28、epared immediately before use. It is essential to check the reducing power of the stannous chloride: dissolve 0,5 g of SnCl22H2O in 2 ml of concentrated hydrochloric acid (20= 1,18 g/ml) and make up to 50 ml with water. Then add 5 g of Rochelle salt (potassium sodium tartrate), then a sufficient qua
29、ntity of sodium bicarbonate for the solution to be alkaline to litmus paper. Titrate with an iodine solution (I2) of c = 0,05 mol/l in the presence of a starch solution as an indicator. 1 ml of iodine solution (I2) of c = 0,05 mol/l corresponds to 0,011 28 g of SnCl22H2O. At least 80 % of the total
30、tin present in the solution thus prepared shall be in bivalent form. For the titration at least 35 ml of the c = 0,1 mol/l iodine solution (I2) should be used. 5.13 Sodium hydroxide solution, containing about 30 % NaOH ( = 1,33 g/ml), ammonia free. 5.14 Standard nitrate-ammoniacal solution Weigh 2,5
31、 g of potassium nitrate and 10,16 g of ammonium sulfate and place them in a 250 ml graduated flask. Dissolve in water and make up to 250 ml. 1 ml of this solution contains 0,01 g of nitrogen. 5.15 Anti-bump granules of pumice stone, washed in hydrochloric acid and calcined. DIN EN 15561:2009-06 EN 1
32、5561:2009 (E) 6 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, s
33、howing all the features of construction, in Figures 1, 2, 3, and 4. Automatic distillation apparatus may be used also, provided that the results are statistically equivalent. DIN EN 15561:2009-06 EN 15561:2009 (E) 7 Dimensions in millimetres Key 1 round-bottomed, long-necked flask of 1 000 ml capaci
34、ty 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
35、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 mean
36、s 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 DIN EN 15561:2009-06 EN 15561:2009 (E) 8 Dimensions in millimetres Key 1 round-bottomed, short-necked flask of 1 0
37、00 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 polytetrafluoroethylene (PTFE) tap (5) for the addition of sodium hydroxi
38、de 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 description Figure 2 Distillation apparatus 2 DIN EN 15561:2009-06
39、EN 15561:2009 (E) 9 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 spherical joint (No 18) at the entrance and a drip cone (the c
40、onnection 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 distillate is collected Figure 3 Distillation apparatus 3 DI
41、N EN 15561:2009-06 EN 15561:2009 (E) 10 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 the side to a funnel with a polytetrafluoroethylene (PTFE)
42、 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 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,
43、 to a glass extension tube (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) 4 500 ml flask for the collection of the distillate 5 PTFE-tap Figure 4 Distillation apparatus 4 DIN EN 15561:2009-06 EN 1556
44、1:2009 (E) 11 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 capacity 250 ml. 7 Sampling and sample preparation Sampling is not part of the method specified in this Technical Specification. A recommended sampling
45、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, to the nearest 0,001 g, 1 g of the sample and place it in the Kjeldahl flask. Add 0,5 g of powdered iron (5.3) and 50 ml of the stannous chloride sol
46、ution (5.12), stir and leave standing for 0,5 h. During the time it is left standing, stir again after 10 min and 20 min. Then add 10 g of potassium sulfate (5.4) and 30 ml of sulfuric acid (5.2). Bring to the boil and maintain boiling for 1 h after the appearance of white fumes. Leave to cool and d
47、ilute with 100 ml to 150 ml of water. Transfer the suspension quantitatively into a 250 ml graduated flask, cool and make up the volume with water, stir and filter through a dry filter into a dry container. Instead of then siphoning off the suspension in order to apply the variant a, b or c, the amm
48、oniacal nitrogen in this solution may also be distilled directly, after adding sufficient sodium hydroxide to ensure a large surplus (5.13). 8.2 Analysis of the solution According to the variant chosen, place in the receiving flask a measured quantity of standard sulfuric acid as indicated in Table
49、1, Table 2 or Table 3. Add the appropriate quantity of the chosen indicator solution (5.11.1 or 5.11.2) 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 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 (5.13) to ensure a considerable excess. Add water in order to obtain a tot
