DIN EN 15562-2009 Fertilizers - Determination of cyanamide nitrogen English version of DIN EN 15562 2009-06《肥料 氰胺氮的测定》.pdf

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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!$X5u“1531882www.di

2、n.deDDIN EN 15562Fertilizers Determination of cyanamide nitrogenEnglish version of DIN EN 15562:2009-06Dngemittel Bestimmung von CyanamidstickstoffEnglische Fassung DIN EN 15562:2009-06SupersedesDIN CEN/TS 15562:2007-07www.beuth.deDocument comprises 15 pagesDIN EN 15562:2009-06 2 National foreword T

3、his 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 und landwirtschaftliche Produkte (Food and Agricultura

4、l 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 2.4 (see Bibliography). Amendments This standard differs from DIN CEN/TS 15562:2007-07 as follow

5、s: a) The standard has been editorially revised. b) Normative references have been updated. Previous editions DIN CEN/TS 15562: 2007-07 EUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN 15562January 2009ICS 65.080 Supersedes CEN/TS 15562:2007 English VersionFertilizers - Determination of cyanamide n

6、itrogenEngrais - Dtermination de lazote cyanamid Dngemittel - Bestimmung von CyanamidstickstoffThis 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 s

7、tatus 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).

8、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,

9、 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 STANDARDIZATIONCOMIT EUROPEN DE NORMALIS

10、ATIONEUROPISCHES 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 15562:2009: EEN 15562:2009 (E) 2 Contents Page Foreword 3 1 Scope 4 2 Normative references

11、 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 . 12 Bibliography . 13 DIN EN 15562:2009-06 EN 15562:2009 (E) 3 Foreword This document (EN 15562:2009) has been

12、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 n

13、ational 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 superse

14、des CEN/TS 15562:2007. 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 Europ

15、ean 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

16、Kingdom. DIN EN 15562:2009-06 EN 15562:2009 (E) 4 1 Scope This European Standard specifies a method for the determination of cyanamide nitrogen in fertilizers. The method is applicable to calcium cyanamide and calcium cyanamide/nitrate mixtures. 2 Normative references The following referenced docume

17、nts 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

18、 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 Spe

19、cification 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 Precipitation of cyanamide nitrogen as a silver complex. Digestion in sulfuric acid with the aid of a catal

20、yst. 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 grade and distilled or demineralized water

21、, free from carbon dioxide and all nitrogenous compounds (grade 3 according to EN ISO 3696:1995). 5.2 Glacial acetic acid 5.3 Ammonia solution, containing 10 % of ammonia gas by mass (20= 0,96 g/ml). 5.4 Ammoniacal silver solution, according to Tollens. Mix 500 ml of 10 % silver nitrate (AgNO3) solu

22、tion in water with 500 ml of 10 % ammonia solution (5.3). Do not expose unnecessarily to light, heat or air. The solution normally keeps for years. As long as the solution remains clear, the reagent is of good quality. DIN EN 15562:2009-06 EN 15562:2009 (E) 5 5.5 Concentrated sulfuric acid, 20= 1,84

23、 g/ml. 5.6 Potassium sulfate, p.a. 5.7 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. 5.8 Sodium hydroxide solution, approximately 30 % NaOH (20= 1,33 g/ml), ammonia free. 5.9 Sulfuric acid, c = 0,05 mol/l. 5.10 Sodium o

24、r potassium hydroxide solution, c = 0,1 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 vol

25、ume 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. 5.11.2 Methyl red indicator solution Dissolve 0,1 g of methyl red in 50 ml of 95 % ethanol. Make up

26、to 100 ml with water and filter if necessary. This indicator may be used (4 to 5 drops) instead of that specified in 5.11.1. 5.12 Anti-bump granules (i.e. pumice stone, glass pearls), washed in hydrochloric acid and calcined. 5.13 Potassium thiocyanate, for the control test. 6 Apparatus 6.1 Distilla

27、tion 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,

28、 in Figures 1, 2, 3, and 4. Automatic distillation apparatus may be used also, provided that the results are statistically equivalent. DIN EN 15562:2009-06 EN 15562:2009 (E) 6 Dimensions in millimetres Key 1 round-bottomed, long-necked flask of 1 000 ml capacity 2 distillation tube with a splash hea

29、d, 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 repla

30、ced 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 means of a rubber tube, the spherical joint

31、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 15562:2009-06 EN 15562:2009 (E) 7 Dimensions in millimetres Key 1 round-bottomed, short-necked flask of 1 000 ml capacity with a spherical joint (

32、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 hydroxide 3 six-bulb condenser with a spherica

33、l 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 15562:2009-06 EN 15562:2009 (E) 8 Dimensions in milli

34、metres 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 connection to the distillation tube may

35、 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 DIN EN 15562:2009-06 EN 15562:2009 (E) 9

36、 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) tap (5) for the addition of sodium hyd

37、roxide (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, to a glass extension tube (when the co

38、nnection 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 15562:2009-06 EN 15562:2009 (E) 10 6.2 Graduated flask, capa

39、city 500 ml. 6.3 Long-necked Kjeldahl flask, of suitable capacity (300 ml to 500 ml). 6.4 Pipette, capacity 50 ml. 6.5 Rotary shaker, 35 to 40 turns per minute. 7 Sampling and sample preparation Sampling is not part of the method specified in this European Standard. A recommended sampling method is

40、given in EN 1482-1. Sample preparation shall be carried out in accordance with EN 1482-2. 8 Procedure SAFETY PRECAUTIONS When using any ammoniacal silver solution safety goggles shall be worn. As soon as a thin membrane forms on the surface of the liquid, an explosion can be produced by agitation an

41、d the greatest caution is essential. 8.1 Preparation of the solution for analysis Weigh, to the nearest 0,001 g, about 2,5 g of the prepared sample and place it in a small glass mortar. Grind the sample three times with water, pouring off the water after each grinding into a 500 ml graduated flask (

42、6.2). Transfer quantitatively the sample into the 500 ml graduated flask, washing the mortar, pestle and funnel with water. Make up with water to approximately 400 ml. Add 15 ml of acetic acid (5.2). Shake on the rotary shaker (6.5) for 2 h. Make up to 500 ml with water, mix and filter. The analysis

43、 shall be carried out as quickly as possible. 8.2 Analysis of the solution Transfer 50 ml of the filtrate into a 250 ml beaker. Add ammonia solution (5.3) until slightly alkaline and add 30 ml of warm ammoniacal silver nitrate (5.4) in order to precipitate the yellow silver complex of the cyanamide.

44、 Leave overnight, filter and wash the precipitate with cold water until it is completely free of ammonia. Place the filter and the precipitate, still moist, in a Kjeldahl flask, add 10 g to 15 g of potassium sulfate (5.6), the catalyst (5.7), in the prescribed proportion, then 50 ml of water and 25

45、ml of concentrated sulfuric acid (5.5). Warm the flask slowly, while shaking it gently until the contents come to the boil. Increase the heat, boil until the contents of the flask become colourless or pale green. Continue boiling for 1 h, then leave to cool. Place in the receiving flask 50 ml of sta

46、ndard sulfuric acid. 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. DIN EN 15562:2009-06 EN 15562:2009

47、(E) 11 Transfer by precision pipette, according to the details given in Table 1, an aliquot portionof the clear solution, into the distillation flask of the apparatus. 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 t

48、he 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 (5.8) (add sufficient NaOH solution (5.8) to ensure the presence of a considerable excess). Gradually warm the flask, to avoid boilin

49、g 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. 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 comple