1、BS EN 15560:2009ICS 65.080NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBRITISH STANDARDFertilizers Determination of totalnitrogen in calciumcyanamide nitrate freeThis British Standardwas published under theauthority of the StandardsPolicy and StrategyCommittee on 30 June2009
2、. BSI 2009ISBN 978 0 580 62388 2Amendments/corrigenda issued since publicationDate CommentsBS EN 15560:2009National forewordThis British Standard is the UK implementation of EN 15560:2009. Itsupersedes DD CEN/TS 15560:2007 which is withdrawn.The UK participation in its preparation was entrusted to T
3、echnicalCommittee CII/37, Fertilisers and related chemicals.A list of organizations represented on this committee can be obtained onrequest to its secretary.This publication does not purport to include all the necessary provisionsof a contract. Users are responsible for its correct application.Compl
4、iance with a British Standard cannot confer immunityfrom legal obligations.BS EN 15560:2009EUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN 15560January 2009ICS 65.080 Supersedes CEN/TS 15560:2007 English VersionFertilizers - Determination of total nitrogen in calcium cyanamidenitrate freeEngrais -
5、 Dosage de lazote total dans la cyanamidecalcique exempte de nitrateDngemittel - Bestimmung von Gesamtstickstoff innitratfreiem KalkstickstoffThis 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 co
6、nditions 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 thre
7、e 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 Aust
8、ria, 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 COMMITT
9、EE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGManagement Centre: rue de Stassart, 36 B-1050 Brussels 2009 CEN All rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN 15560:2009: EBS EN 15560:2009EN 15560:2009
10、(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 Calculation and expression of the result . 12 10 Test report . 13 Bibliography . 14 BS EN 15560:2009EN 15560:2
11、009 (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 Standard shall be given the status of a national standard, either by publication of an identical text or by
12、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 identi
13、fying 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 Trade Association. According to the CEN/CENELEC Internal Regulations, the national standards organizations of
14、 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, Slov
15、akia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. BS EN 15560:2009EN 15560:2009 (E) 4 1 Scope This European Standard specifies a method for the determination of total nitrogen in nitrate-free calcium cyanamide. 2 Normative references The following referenced documents are indispensa
16、ble 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 prepara
17、tion 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 tes
18、t 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 in sulfuric acid with the aid of a catalyst. Distillation of the ammonia from an alkaline solution, absorption in a
19、n 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 grade and distilled or demineralized water, free from carbon dioxide and all nitrogenous compounds (grade 3 according
20、 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 copper(II)oxide or 0,95 g to 1,25 g of copper(II)sulfate pentahydrate for each determination. BS EN 15560:2009EN 1
21、5560:2009 (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 hydroxide solution, carbonate free, c = 0,1 mol/l. 5.8 Sulfuric acid, c = 0,1 mol/l. 5.9 Sodium or potassium hydroxide
22、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 5.12.1 Mixed indicator Solution A: Dissolve 1 g of methyl red in 37 ml of sodium hydroxide solution c = 0,1 mol/l and make
23、 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 solu
24、tion. 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. 5.13 Anti-bump granules of pumice stone, washed in hydrochloric acid
25、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 a splash head. The equipment is made of borosilicate glass. NOTE The different types of equipment recommended for this
26、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. BS EN 15560:2009EN 15560:2009 (E) 6 Dimensions in millimetres Key 1 round-bottomed, long-nec
27、ked 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)
28、 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 distillat
29、ion 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 BS EN 15560:2009EN 15560:2009 (E) 7 Dimensions in millimetres Key 1 round-bottomed, s
30、hort-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 polytetrafluoroethylene (PTFE) tap (5) for the ad
31、dition 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 connection 4 500 ml flask in which the distillate is collected 5 PTFE-tap a enlarged description Figure 2 Distillation apparatus
32、 2 BS EN 15560:2009EN 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 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
33、 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 distillate is collected Figure 3 Distilla
34、tion apparatus 3 BS EN 15560:2009EN 15560:2009 (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 the side to a funnel with a polytetrafluoroet
35、hylene (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 connection with an appropriate clip) 3 six-bulb condenser with a spherical joint (No 18) at the entrance, joined at the issue, by a rubbe
36、r connection, 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 BS EN 15560:200
37、9EN 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 capacity 250 ml. 7 Sampling and sample preparation Sampling is not part of the method specified in this Technical Specification. A recommended s
38、ampling 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 50 ml of diluted sulfuric acid (5.2), 10 g to 15 g of potas
39、sium 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 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
40、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 quantity 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.
41、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 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
42、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 volume of about 350 ml and several grains of pumice in order to control the boiling. Assemble the distillation apparatus, and taking care to avo
43、id 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 avoid 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
44、 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. 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
45、 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 adop
46、ted (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 far as possible, exceed 45 ml. BS EN 15560:2009EN 15560:2009 (E) 11 Table 1 Weighing, dilution and calculation variant a Declaration % N Amoun
47、t 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 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 t
48、o 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
49、; A = volume of sodium or potassium hydroxide used for the back titration, in millilitres; F = factor comprising the amount weighed, the dilution, the aliquot part of solution of the sample to be distilled and the volumetric equivalent. Table 2 Weighing, dilution and calculation variant b 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 10 7 5 7 500 500 500 500 500 100 50 50 50 20 (50 A) 0,1
