1、BS EN 15558:2009ICS 65.080NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBRITISH STANDARDFertilizers Determination ofnitric and ammoniacalnitrogen according toUlschThis British Standardwas published under theauthority of the StandardsPolicy and StrategyCommittee on 28 February
2、2009 BSI 2009ISBN 978 0 580 62386 8Amendments/corrigenda issued since publicationDate CommentsBS EN 15558:2009National forewordThis British Standard is the UK implementation of EN 15558:2009. Itsupersedes DD CEN/TS 15558:2007 which is withdrawn.The UK participation in its preparation was entrusted t
3、o TechnicalCommittee 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.Co
4、mpliance with a British Standard cannot confer immunityfrom legal obligations.BS EN 15558:2009EUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN 15558January 2009ICS 65.080 Supersedes CEN/TS 15558:2007 English VersionFertilizers - Determination of nitric and ammoniacal nitrogenaccording to UlschEngra
5、is - Dosage de lazote nitrique et ammoniacal selonUlschDngemittel - Bestimmung von Nitrat- undAmmoniumstickstoff nach UlschThis 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 givin
6、g 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 three official version
7、s (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 Austria, Belgium, Bulg
8、aria, 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 COMMITTEE FOR STANDARDIZA
9、TIONCOMIT 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 15558:2009: EBS EN 15558:2009EN 15558:2009 (E) 2 Contents For
10、eword 31 Scope 42 Normative references 43 Terms and definitions .44 Principle 45 Reagents .46 Apparatus .57 Sampling and sample preparation 108 Procedure 109 Calculation and expression of the result . 1110 Test report . 12Bibliography . 13BS EN 15558:2009EN 15558:2009 (E) 3 Foreword This document (E
11、N 15558:2009) 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 rights
13、. This document supersedes CEN/TS 15558:2007. 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
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, Swit
15、zerland and the United Kingdom. BS EN 15558:2009EN 15558:2009 (E) 4 1 Scope This European Standard specifies a method for the determination of nitrate and ammoniacal nitrogen with reduction according to Ulsch. The method is applicable to all nitrogenous fertilizers, including compound fertilizers, i
16、n which nitrogen is found exclusively in nitrate form, or in ammoniacal and nitrate form. 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
17、 of the referenced document (including any amendments) applies. EN 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 an
18、d liming materials and soil improvers Vocabulary Part 2: Terms relating 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 an
19、d EN 12944-2:1999 apply. 4 Principle Reduction of nitrates and nitrites to ammonia by means of metallic iron in an acid medium and displacement of the ammonia thus formed by the addition of an excess of sodium hydroxide: distillation of the ammonia and determination of the yield of ammonia in a know
20、n volume of standard sulfuric acid solution and titration of the excess sulfuric 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 nitro
21、genous compounds (grade 3 according to EN ISO 3696:1995). 5.2 Diluted hydrochloric acid Mix one volume of concentrated hydrochloric acid solution, (HCl) = 1,18 g/ml, with one volume of water. BS EN 15558:2009EN 15558:2009 (E) 5 5.3 Sulfuric acid, c = 0,05 mol/l. 5.4 Sodium or potassium hydroxide sol
22、ution, carbonate free, c = 0,1 mol/l. 5.5 Sulfuric acid solution, approximately 30 % H2SO4(mass concentration), ammonia free. 5.6 Powdered iron, reduced in hydrogen. The prescribed quantity of iron shall be able to reduce at least 0,05 g of nitrate nitrogen. 5.7 Sodium hydroxide solution, 30 % mass
23、concentration, of approximately (NaOH) = 1,33 g/ml, ammonia free. 5.8 Indicator solutions 5.8.1 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
24、 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 solution. 5.8.2 Methyl red indicator solution Dissolve 0,1 g of methyl red in 50 ml of 95 % e
25、thanol. 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 5.8.1. 5.9 Anti-bump granules, for example pumice stone, washed in hydrochloric acid and calcined. 5.10 Sodium nitrate, p. a. 6 Apparatus 6.1 Distillation apparatus Co
26、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,
27、 3 and 4. An automatic distillation apparatus may also be used, provided that the results are statistically equivalent. BS EN 15558:2009EN 15558:2009 (E) 6 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
28、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 conn
29、ection 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 by a
30、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 15558:2009EN 15558:2009 (E) 7 Dimensions in millimetres Key 1 round-bottomed, short-necked flask of 1 000 ml capacity with a spherical joint (No 35) 2 distillation tube
31、 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 the ent
32、rance 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 15558:2009EN 15558:2009 (E) 8 Dimensions in millimetres Key 1 round-bottomed, lo
33、ng-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 of a rubbe
34、r 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 15558:2009EN 15558:2009 (E) 9 Dimensions in millimetres Key 1 roun
35、d-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 rubber bung may be
36、 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 distillation tube is
37、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 15558:2009EN 15558:2009 (E) 10 6.2 Pipettes, of capacity 10 ml, 20 ml, 25 ml, 50 ml, 100 ml and 20
38、0 ml. 6.3 Graduated flasks, 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 be carried out i
39、n 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 of 5 g or 7 g o
40、r 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 dissolved, make up t
41、he 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 the rotary shaker
42、(6.4). Make up the volume with water, mix and filter through a dry filter into a dry receptacle. 8.2 Procedure Place in the receiving flask an exactly measured quantity of 50 ml standard sulfuric acid and add the appropriate quantity of indicator solution 5.8.1 or 5.8.2. The end of the extension tub
43、e of the condenser shall be below the surface of the standard acid in the receiving flask. Using a precision pipette, transfer an aliquot part of the clear solution as indicated in Table 1 and place it in the distillation flask of the apparatus. Add 350 ml of water, 20 ml of 30 % sulfuric acid solut
44、ion (5.5) stir, and add 5 g of reduced iron (5.6). Wash the neck of the flask with several millilitres of water, and place in the neck of the flask a small, long-stemmed funnel. Heat in a boiling water bath for an hour and then wash the stem of the funnel with a few millilitres of water. Taking care
45、 to avoid any loss of ammonia, add to the contents of the distillation flask 50 ml of concentrated sodium hydroxide solution (5.7), or in the cases where 20 ml of hydrochloric acid (5.2) has been used to dissolve the sample, add 60 ml of concentrated sodium hydroxide solution (5.7). Assemble the dis
46、tillation apparatus. 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 about 250 ml. The condenser shall be regulated in such a way that a continuous flow of condensate is en
47、sured. The distillation should be completed BS EN 15558:2009EN 15558:2009 (E) 11 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 a
48、ppropriate 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 adopted (see NOTE). NOTE Standard solutions of different str
49、engths may be used for the back titration provided that the volumes used for the titration do not, as far as possible, exceed 45 ml. Table 1 Weighing, dilution and calculation 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 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 nitrog
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