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1、BS EN 15475:2009 ICS 65.080 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW BRITISH STANDARD Fertilizers Determination of ammoniacal nitrogen This British Standard was published under the authority of the Standards Policy and Strategy Committee on 28 February 2009 BSI 2009 ISB
2、N 978 0 580 62381 3 Amendments/corrigenda issued since publication DateComments BS EN 15475:2009 National foreword This British Standard is the UK implementation of EN 15475:2009. It supersedes DD CEN/TS 15475:2006 which is withdrawn. The UK participation in its preparation was entrusted to Technica
3、l Committee CII/37, Fertilisers and related chemicals. A list of organizations represented on this committee can be obtained on request to its secretary. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Compli
4、ance with a British Standard cannot confer immunity from legal obligations. BS EN 15475:2009 EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 15475 January 2009 ICS 65.080Supersedes CEN/TS 15475:2006 English Version Fertilizers - Determination of ammoniacal nitrogen Engrais - Dtermination de laz
5、ote ammoniacalDngemittel - Bestimmung von Ammoniumstickstoff This 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 European Standard the status of a national standard wi
6、thout any alteration. Up-to-date lists and bibliographical references concerning such national standards 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 langua
7、ge made by translation under the responsibility of a CEN member into its own language and notified to the CEN Management 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
8、, 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 STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMI
9、TEE FR NORMUNG Management Centre: rue de Stassart, 36 B-1050 Brussels 2009 CENAll rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 15475:2009: E BS EN 15475:2009 EN 15475:2009 (E) 2 Contents Page Foreword 3 1 Scope 4 2 Normative references
10、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 Precision 12 11 Test report . 13 Annex A (informative) Results of the inter-laboratory tests 14 Bibliography . 15 w w w . b z
11、 f x w . c o m BS EN 15475:2009 EN 15475:2009 (E) 3 Foreword This document (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
12、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 may be the subject of patent rights. CEN and/or CENELE
13、C shall not be held responsible for identifying any or all such patent rights. 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 Regulation
14、s, 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, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherland
15、s, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. w w w . b z f x w . c o m BS EN 15475:2009 EN 15475:2009 (E) 4 1 Scope This European Standard specifies a method for the determination of the ammoniacal nitrogen content in fertilizers. The m
16、ethod is applicable to all nitrogenous fertilizers including compound fertilizers, in which nitrogen is 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
17、 nitrogenous compounds. 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 amendments) applies. EN
18、 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 Part 2: Terms rel
19、ating 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 Displacement of ammonia by me
20、ans of an excess of sodium hydroxide, distillation and determining the yield of ammonia in a given volume 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 g
21、rade and distilled or demineralized water, free from carbon dioxide and all nitrogenous compounds (grade 3 according to EN ISO 3696:1995). w w w . b z f x w . c o m BS EN 15475:2009 EN 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 S
22、ulfuric acid (for variant a), c = 0,05 mol/l. 5.4 Sodium or potassium hydroxide solution (for variant a), carbonate free, c = 0,1 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 =
23、 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 variant 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 M
24、ixed 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 A with two volumes of B. This indicator is violet in acid solution, grey
25、in neutral solution and green in alkaline solution. Use 0,5 ml (10 drops) of this indicator solution. 5.10.2 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
26、 the preceding one. This indicator is red in acid solution and yellow in alkaline solution. 5.11 Anti-bump granules (i. e. pumice 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 o
27、f 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 in Figures 1, 2, 3 and 4. w w w . b z f x w . c o m B
28、S EN 15475:2009 EN 15475:2009 (E) 6 An automatic distillation apparatus may also be used, provided that the results are statistically equivalent. 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
29、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 4 six-bulb condenser with spherical joint (No 18) at the ent
30、rance, 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 may be replaced by a suitable rubber bung) 5 500-ml-flask in which the distillate is collected 6 PTF
31、E-tap (the tap may likewise be replaced by a rubber connection with a clip) Figure 1 Distillation apparatus 1 w w w . b z f x w . c o m BS EN 15475:2009 EN 15475:2009 (E) 7 Dimensions in millimetres Key 1 round-bottomed, short-necked flask of 1 000 ml capacity with a spherical joint (No 35) 2 distil
32、lation 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 spherical joint (No 18)
33、 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 w w w . b z f x w . c o m BS EN 15475:2009 EN 15475:2009 (E) 8 Dimensions i
34、n 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 connection to the distillation t
35、ube 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 w w w . b z f x w . c o m BS EN 1
36、5475:2009 EN 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 side to a funnel with a polytetrafluoroethylene (PTFE) tap (5) f
37、or 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, to a glas
38、s 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 w w w . b z f x w . c o m BS EN 15475:
39、2009 EN 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 specified in this document. A recommended
40、 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 quantity of 5 g, 7 g, or 10 g of the pre
41、pared 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). Filter through a filter into a 500-m
42、l 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 quantity of the chosen indicator solution
43、(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 aliquot portion of the clear solution, in
44、to 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 contents of the distillation flask 10 ml
45、 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 commences, distil at a rate of about 1
46、00 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
47、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 surplus acid with the standard soluti
48、on 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. w w w . b z f x w . c o m BS EN 154
49、75:2009 EN 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 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