BS EN 15475-2009 Fertilizers — nDetermination of nammoniacal nitrogen《肥料 氨态氮的测定》.pdf

1、BS EN 15475:2009ICS 65.080NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBRITISH STANDARDFertilizers Determination ofammoniacal nitrogenThis British Standardwas published under theauthority of the StandardsPolicy and StrategyCommittee on 28 February2009 BSI 2009ISBN 978 0 580

2、62381 3Amendments/corrigenda issued since publicationDate CommentsBS EN 15475:2009National forewordThis British Standard is the UK implementation of EN 15475:2009. Itsupersedes DD CEN/TS 15475:2006 which is withdrawn.The UK participation in its preparation was entrusted to TechnicalCommittee CII/37,

3、 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.Compliance with a British Stan

4、dard cannot confer immunityfrom legal obligations.BS EN 15475:2009EUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN 15475January 2009ICS 65.080 Supersedes CEN/TS 15475:2006 English VersionFertilizers - Determination of ammoniacal nitrogenEngrais - Dtermination de lazote ammoniacal Dngemittel - Besti

5、mmung von AmmoniumstickstoffThis European Standard was approved by CEN on 30 November 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 li

6、sts 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). A version in any other language made by translationunder the respo

7、nsibility 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, Denmark, Estonia, Finland,France, Germany, Greece, Hungary, Icela

8、nd, 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 NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGManagement Centre: rue de Stass

9、art, 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 15475:2009: EBS EN 15475:2009EN 15475:2009 (E) 2 Contents Page Foreword 3 1 Scope 4 2 Normative references 4 3 Terms and definitions .4 4 Principle 4 5 Reag

10、ents .4 6 Apparatus .5 7 Sampling and sample preparation 10 8 Procedure 10 9 Calculation and expression of the result . 12 10 Precision 12 11 Test report . 13 Annex A (informative) Results of the inter-laboratory tests 14 Bibliography . 15 BS EN 15475:2009EN 15475:2009 (E) 3 Foreword This document (

11、EN 15475:2009) 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 endorsement, at the latest by July

12、 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 identifying any or all such patent right

13、s. This document supersedes CEN/TS 15475:2006. 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

14、 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, Slovakia, Slovenia, Spain, Sweden, Swi

15、tzerland and the United Kingdom. BS EN 15475:2009EN 15475:2009 (E) 4 1 Scope This European Standard specifies a method for the determination of the ammoniacal nitrogen content in fertilizers. The method is applicable to all nitrogenous fertilizers including compound fertilizers, in which nitrogen is

16、 found exclusively either in the form of ammonium salts or ammonium salts together with nitrates. This European Standard is not applicable to fertilizers containing urea, cyanamide or other organic nitrogenous compounds. 2 Normative references The following referenced documents are indispensable for

17、 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 preparation EN

18、 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 test metho

19、ds (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 Displacement of ammonia by means of an excess of sodium hydroxide, distillation and determining the yield of ammonia in a given volu

20、me of a standard sulfuric acid and titration of the excess acid by means of a standard solution of sodium or potassium hydroxide. 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 (grad

21、e 3 according to EN ISO 3696:1995). BS EN 15475:2009EN 15475:2009 (E) 5 5.2 Diluted hydrochloric acid, mix one volume of (HCl) = 1,18 g/ml with one volume of water. 5.3 Sulfuric acid (for variant a), c = 0,05 mol/l. 5.4 Sodium or potassium hydroxide solution (for variant a), carbonate free, c = 0,1

22、mol/l. 5.5 Sulfuric acid (for variant b, see NOTE in 8.2), c = 0,1 mol/l. 5.6 Sodium or potassium hydroxide solution (for variant b, see NOTE in 8.2), carbonate free, c = 0,2 mol/l. 5.7 Sulfuric acid (for variant c, see NOTE in 8.2), c = 0,25 mol/l. 5.8 Sodium or potassium hydroxide solution (for va

23、riant c, see NOTE in 8.2), carbonate free, c = 0,5 mol/l. 5.9 Sodium hydroxide, 30 %, of approximately (NaOH) = 1,33 g/ml, ammonia free. 5.10 Indicator solutions 5.10.1 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

24、water. Solution B: Dissolve 1 g of methylene blue in water and make up to 1 l. Mix one volume of A with two volumes of 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. 5.10.2 Methyl red indicator

25、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 the preceding one. This indicator is red in acid solution and yellow in alkaline solution. 5.11 Anti-bump granules (i. e. pumice

26、stone, glass pearls), washed in hydrochloric acid and calcined. 5.12 Ammonium sulfate, 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 diff

27、erent types of equipment recommended for this determination are reproduced, showing all the features of construction in Figures 1, 2, 3 and 4. BS EN 15475:2009EN 15475:2009 (E) 6 An automatic distillation apparatus may also be used, provided that the results are statistically equivalent. Dimensions

28、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 to the condenser may be replaced by an appropriate rubber connection) 3 funnel

29、with a polytetrafluoroethylene (PTFE) tap (6) for the addition of sodium hydroxide 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 m

30、eans 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 (the tap may likewise be replaced by a rubber connection with a clip) Figure 1 Distillation apparatus 1 BS EN 15475:2009EN 15475:2009 (E) 7 Dimensions

31、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 spherical joint (No 18) at the issue, connected at the side to a funnel with a polytetrafl

32、uoroethylene (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 connection 4 500-ml-flask in which the distillate is collected 5 PTFE-tap a enlarged descr

33、iption Figure 2 Distillation apparatus 2 BS EN 15475:2009EN 15475:2009 (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 spher

34、ical 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 di

35、stillate is collected Figure 3 Distillation apparatus 3 BS EN 15475:2009EN 15475:2009 (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 si

36、de 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 connection with an appropriate clip) 3 six-bulb condenser with a spherical joint (No 18) at the en

37、trance, 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 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 D

38、istillation apparatus 4 BS EN 15475:2009EN 15475:2009 (E) 10 6.2 Pipettes, capacity of 10 ml, 20 ml, 25 ml, 50 ml, 100 ml and 200 ml. 6.3 Graduated flasks, capacity 500 ml. 6.4 Rotary shaker, 35 to 40 revolutions per minute. 7 Sampling and sample preparation Sampling is not part of the method specif

39、ied in this document. 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 According to Table 1, Table 2 or Table 3, depending on the variant chosen, weigh to the nearest 0,001 g a quant

40、ity of 5 g, 7 g, or 10 g of the prepared sample and transfer it into a 500-ml flask. Add 50 ml of water and then 20 ml of hydrochloric acid (5.2). Shake. Leave undisturbed until the evolution of carbon dioxide has ceased. Add 200 ml of water and shake for half an hour with the rotary shaker (6.4). F

41、ilter through a filter into a 500-ml graduated flask and make up to the volume with water. 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 quantit

42、y of the chosen indicator solution (5.10.1 or 5.10.2) 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. Transfer by precision pipette, according to the details given in Table 1, an aliquo

43、t 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 the distillation apparatus and taking care to avoid any loss of ammonia, add to the conten

44、ts of the distillation flask 10 ml of concentrated sodium hydroxide solution (5.9) or 20 ml of the sodium hydroxide solution (5.9) in the cases where one has used 20 ml hydrochloric acid (5.2) in order to dissolve the test sample. Gradually warm the flask; avoid boiling vigorously. When boiling comm

45、ences, distil at a 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 evol

46、ved, 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 extension with a little water and titrate the sur

47、plus 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 far as possible, exceed 40 ml to 45 ml. B

48、S EN 15475:2009EN 15475:2009 (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 resulta 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

49、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 c=0,1 mol/l. aFor the purposes of the formula for expression of the result: 50 = millilitres of standard solution of sulfuric acid to be placed in the receiving flask; A = millilitres of sodium or potassium hydroxide used for the back titration; F = factor comprising the amount weighed, the dilu