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1、? ? ? ? ? ? ? ? ? This British Standard was published under the authority of the Standards Policy and Strategy Committee on 30 June 2009 ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? BS EN 15559:2009 EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 15559 January 2009 ICS 65.080Supersedes CEN/TS 15559:2007 Eng
2、lish Version Fertilizers - Determination of nitric and ammoniacal nitrogen according to Arnd Engrais - Dosage de lazote nitrique et ammoniacal selon Arnd Dngemittel - Bestimmung von Nitrat- und Ammoniumstickstoff nach Arnd This European Standard was approved by CEN on 6 December 2008. CEN members ar
3、e bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to
4、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 translation under the responsibility of a CEN member into its own language and notified to the CEN Management Centre has the sam
5、e 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, Norway, Poland, Portugal, R
6、omania, 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 CENAll rights of exploitation in any form and by any means reser
7、ved worldwide for CEN national Members. Ref. No. EN 15559:2009: E BS EN 15559:2009 EN 15559:2009 (E) 2 Contents Page Foreword 3 1Scope 4 2Normative references 4 3Terms and definitions .4 4Principle 4 5Reagents .4 6Apparatus .6 7Sampling and sample preparation 11 8Procedure 11 9Calculation and expres
8、sion of the result . 14 10Test report . 14 Bibliography . 15 ? BS EN 15559:2009 EN 15559:2009 (E) 3 Foreword This document (EN 15559:2009) 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
9、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 may be
10、 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 15559:2007. This document has been prepared under a mandate given to CEN by the European Commission and the European Free Trade Association.
11、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, Italy,
12、Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. ? BS EN 15559:2009 EN 15559:2009 (E) 4 1 Scope This European Standard specifies a method for the determination of nitric and ammoniacal nitroge
13、n with reduction according to Arnd (modified for each of the variants a, b and c). The method is applicable to all nitrogenous fertilizers, including compound fertilizers, in which nitrogen is found exclusively in nitrate form, or in ammoniacal and nitrate form. 2 Normative references The following
14、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 1482-2, Fertilizers and liming materials Sampling and sample
15、 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 relating to fertilizers EN ISO 3696:1995, Water for analytical l
16、aboratory 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 Reduction of nitrates and nitrites to ammonia in a neutral aqueous solution by means of a
17、metallic alloy composed of 60 % Cu and 40 % Mg (Arnds alloy) in the presence of magnesium chloride. Distillation of the ammonia and determination of the yield in a known volume of standard sulfuric acid solution. Titration of the excess acid by means of a standard solution of sodium or potassium hyd
18、roxide. 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 Diluted hydrochloric acid Mix one volume of concentrated hydrochloric acid solutio
19、n, (HCl) = 1,18 g/ml, with one volume of water. ? BS EN 15559:2009 EN 15559:2009 (E) 5 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 mol/l. 5.5 Sulfuric acid (for variant b, see NOTES in 8.2), c = 0,1 mol/l. 5.6
20、 Sodium or potassium hydroxide solution (for variant b, see NOTES in 8.2), carbonate free, c = 0,2 mol/l. 5.7 Sulfuric acid (for variant c, see NOTES in 8.2), c = 0,25 mol/l. 5.8 Sodium or potassium hydroxide solution (for variant c, see NOTES in 8.2), carbonate free, c = 0,5 mol/l. 5.9 Sodium hydro
21、xide solution, approximately c = 2 mol/l. 5.10 Arnds alloy, powdered so as to pass through a sieve with apertures less than 1 mm square. 5.11 Magnesium chloride solution, ? = 20 %. Dissolve 200 g of magnesium chloride (MgCl2.6H2O) in approximately 600 ml to 700 ml of water in a 1 l flat- bottomed fl
22、ask. To prevent frothing, add 15 g of magnesium sulfate (MgSO4.7H2O). After dissolution add 2 g of magnesium oxide and a few anti-bump granules of pumice stone and concentrate the suspension to 200 ml by boiling, thus expelling any trace of ammonia from the reagents. Cool, make up the volume to 1 l
23、and filter. 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 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
24、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. 5.12.2 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
25、necessary. This indicator may be used (4 to 5 drops) instead of that specified in 5.12.1. 5.12.3 Congo red indicator solution Dissolve 3 g of Congo red in 1 l of warm water and filter if necessary after cooling. This indicator may be used, instead of that specified in 5.12.1.or 5.12.2, in the neutra
26、lization of acid extracts before distillation, using 0,5 ml per 100 ml of liquid to be neutralized. 5.13 Anti-bump granules, for example pumice stone, washed in hydrochloric acid and reclaimed. ? BS EN 15559:2009 EN 15559:2009 (E) 6 5.14 Sodium nitrate, p.a. 6 Apparatus 6.1 Distillation apparatus Co
27、nsisting 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, in Figures 1, 2,
28、 3 and 4. An automatic distillation apparatus may also be used, provided that the results are statistically equivalent. ? BS EN 15559:2009 EN 15559:2009 (E) 7 Dimensions in millimetres Key 1 round-bottomed, long-necked flask of 1 000 ml capacity 2 distillation tube with a splash head, connected to t
29、he 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 replaced by a rubber c
30、onnection 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 may be replaced b
31、y 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 15559:2009 EN 15559:2009 (E) 8 Dimensions in millimetres Key 1 round-bottomed, short-necked flask of 1 000 ml capacity with a spherical joint (No 35) 2 distillati
32、on 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) at
33、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 ? BS EN 15559:2009 EN 15559:2009 (E) 9 Dimensions in millimetres Key 1 round-bo
34、ttomed, 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 be effected by means
35、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 ? BS EN 15559:2009 EN 15559:2009 (E) 10 Dimensions in millimet
36、res 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 hydroxide (a suitable rubb
37、er 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 connection to the distill
38、ation 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 15559:2009 EN 15559:2009 (E) 11 6.2 Pipettes, of capacity 10 ml, 20 ml, 25 ml, 50
39、ml, 100 ml and 200 ml. 6.3 Graduated flask, of capacity 500 ml. 6.4 Rotary shaker, 35 to 40 turns per minute. 7 Sampling and sample preparation Sampling is not part of the method specified in this Technical Specification. A recommended sampling method is given in EN 1482-1. Sample preparation shall
40、be carried out in accordance with EN 1482-2. 8 Procedure 8.1 Preparation of the solution 8.1.1 General Carry out a solubility test on the sample in water at room temperature and in the proportion of 2 % (mass concentration). Weigh to 0,001 g, according to the indications given in Table 1, a quantity
41、 of 5 g or 7 g or 10 g of the prepared sample and place it in a 500 ml graduated flask. According to the result of the solubility test, proceed as follows: 8.1.2 Products completely soluble in water Add to the flask the quantity of water needed to dissolve the sample; shake, and when completely diss
42、olved, make up the volume and mix thoroughly. 8.1.3 Products not completely soluble in water Add to the flask 50 ml of water and then 20 ml of hydrochloric acid (5.2). Shake and leave undisturbed until the evolution of carbon dioxide has ceased. Add 400 ml of water and shake for half an hour with th
43、e rotary shaker (6.4). Make up the volume with water, mix and filter through a dry filter into a dry receptacle. 8.2 Analysis of the solution According to the chosen variant, place in the receiving flask the exactly measured quantity of standard sulfuric acid as indicated in Table 1, Table 2 or Tabl
44、e 3. Add the appropriate quantity of chosen indicator solution (5.12.1 or 5.12.2) and finally, sufficient water to give a volume of at least 50 ml. The end of the extension tube of the condenser shall be below the surface of the solution. Using a precision pipette, take, according to Table 1, Table
45、2 or Table 3, an adequate aliquot of the clear solution. Place it in the distillation flask. ? BS EN 15559:2009 EN 15559:2009 (E) 12 Add sufficient water to obtain a total volume of about 350 ml (see NOTE 1), 10 g of Arnds alloy (5.10), 50 ml of magnesium chloride solution (5.11) and a few fragments
46、 of pumice stone (5.13). Rapidly connect the flask to the distillation apparatus. Heat gently for about 30 min. Then increase the heating to distil the ammonia. Continue the distillation for about 1 h. After this time, the residue in the flask ought to have a syrupy consistency. When the distillation has finished, 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