BS EN 16196-2012 Fertilizers Manganimetric determination of extracted calcium following precipitation in the form of oxalate《肥料 提取钙后草酸形式沉淀的高锰酸钾测定》.pdf

1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS EN 16196:2012Fertilizers Manganimetric determination of extracted calcium following precipitation in the form of oxalateBS EN 16196:2012 BRITISH STANDARDNational forewordThis

2、British Standard is the UK implementation of EN 16196:2012. It supersedes DD CEN/TS 16196:2011, which is withdrawn.The UK participation in its preparation was entrusted to T e c h n i c a l C o m m i t t e e C I I / 3 7 , F e r t i l i s e r s a n d r e l a t e d c h e m i c a l s .A list of organiz

3、ations 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. The British Standards Institution 2012. Published by BSI Standards Limited 2012

4、.ISBN 978 0 580 78185 8 ICS 65.080 Compliance with a British Standard cannot confer immunity from legal obligations.This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 December 2012.Amendments issued since publicationDate T e x t a f f e c t e

5、 dBS EN 16196:2012EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 16196 November 2012 ICS 65.080 Supersedes CEN/TS 16196:2011English Version Fertilizers - Manganimetric determination of extracted calcium following precipitation in the form of oxalate Engrais - Dosage manganimtrique du calcium e

6、xtrait aprs prcipitation sous forme doxalate Dngemittel - Manganometrische Bestimmung von Calcium nach Oxalatfllung This European Standard was approved by CEN on 6 October 2012. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this E

7、uropean 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 the CEN-CENELEC Management Centre or to any CEN member. This European Standard exists in three official vers

8、ions (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-CENELEC Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria,

9、 Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, S

10、witzerland, Turkey and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: Avenue Marnix 17, B-1000 Brussels 2012 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Member

11、s. Ref. No. EN 16196:2012: EBS EN 16196:2012EN 16196:2012 (E) 2 Contents Page Foreword 31 Scope 42 Normative references 43 Terms and definitions .44 Sampling .45 Principle 46 Reagents .47 Apparatus .58 Preparation of the test portion .59 Procedure .59.1 Preparation of the calcium oxalate 59.2 Titrat

12、ion of the oxalate precipitate .510 Calculation and expression of the result 511 Precision .611.1 Inter-laboratory test .611.2 Repeatability .611.3 Reproducibility .612 Test report 7Annex A (informative) Statistical results of the inter-laboratory tests 8Bibliography . 10BS EN 16196:2012EN 16196:201

13、2 (E) 3 Foreword This document (EN 16196:2012) 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 en

14、dorsement, at the latest by May 2013, and conflicting national standards shall be withdrawn at the latest by May 2013. 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 identifyin

15、g any or all such patent rights. This document supersedes CEN/TS 16196:2011. The following changes have been made to the former edition: a) the CEN Technical Specification has been adopted as a European Standard; b) the document has been editorially revised. This document has been prepared under a m

16、andate given to CEN by the European Commission and the European Free Trade Association. According to the CEN/CENELEC Internal Regulations, the national standards organisations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech

17、 Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom.

18、 BS EN 16196:2012EN 16196:2012 (E) 4 1 Scope This European Standard specifies a manganimetric method for the determination of the calcium content in fertilizer extracts. This method is applicable to EC fertilizers for which a declaration of the total and/or water-soluble calcium content is provided

19、for in Regulation (EC) No 2003/2003, Annex I 3. 2 Normative references The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition

20、 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

21、d liming materials and soil improvers Vocabulary Part 2: Terms relating to fertilizers EN 15960, Fertilizers Extraction of total calcium, total magnesium, total sodium and total sulfur in the forms of sulfates EN 15961, Fertilizers Extraction of water soluble calcium, magnesium, sodium and sulfur in

22、 the form of sulfates 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 Sampling Sampling is not part of the method specified in this document. A recommended sampling method is given in EN 1482-1. Sample prepara

23、tion shall be carried out in accordance with EN 1482-2. Grinding of the laboratory sample is recommended for homogeneity reasons. 5 Principle Precipitation of the calcium contained in an aliquot of the extraction solution in the form of an oxalate, which is determined by titration using potassium pe

24、rmanganate. 6 Reagents 6.1 Diluted hydrochloric acid, one volume of hydrochloric acid, = 1,18g/ml, and one volume of water. 6.2 Sulfuric acid, 1:10 diluted, one volume of sulfuric acid, = 1,84 g/ml, in ten volumes of water. 6.3 Ammonia solution, 1:1 diluted, one volume of ammonia, = 0,88 g/ml, and o

25、ne volume of water. 6.4 Ammonia oxalate, (NH4)2 C2O4H2O, saturated solution at ambient temperature, approximately = 40 g/l. BS EN 16196:2012EN 16196:2012 (E) 5 6.5 Citric acid solution, 30 % (mass concentration). 6.6 Ammonium chloride solution, 5 % (mass concentration). 6.7 Solution of bromothymol b

26、lue in ethanol, at 95 %, 0,1 % (mass concentration). 6.8 Solution of bromocresol green in ethanol, at 95 %, 0,04 % (mass concentration). 6.9 Standard solution of potassium permanganate, c = 0,02 mol/l. 7 Apparatus 7.1 Filter crucible, with 5 m to 20 m porosity sintered glass. 7.2 Hot water bath. 7.3

27、 400 ml beaker. 8 Preparation of the test portion Using a pipette, take an aliquot portion of the extraction solution obtained according to EN 15960 or EN 15961, containing between 15 mg and 50 mg of Ca (= 21 mg to 70 mg of CaO). The volume of this aliquot is v2. Pour into a beaker (7.3). If necessa

28、ry, neutralise, turning of indicator (6.7) from green to blue, with a few drops of the ammonia solution (6.3). Add 1 ml of the citric acid solution (6.5) and 5 ml of ammonium chloride solution (6.6). 9 Procedure 9.1 Preparation of the calcium oxalate Add approximately 100 ml of water. Bring to the b

29、oil, add eight to ten drops of indicator solution (6.8) and, slowly, 50 ml of a hot ammonium oxalate solution (6.4). If a precipitate forms, dissolve by adding a few drops of hydrochloric acid (6.1). Neutralise very slowly with ammonia solution (6.3) while stirring continuously to a pH of 4,4 to 4,6

30、, turning of indicator (6.8) from green to blue. Place the beaker in a boiling hot water bath (7.2) for approximately 30 min. Remove the beaker from the bath, leave standing for 1 h and filter through the crucible (7.1). 9.2 Titration of the oxalate precipitate Wash the beaker and crucible until the

31、 excess ammonium oxalate has been completely removed (this can be checked by the absence of chloride in the washing water). Place the crucible in the beaker (7.3) and dissolve the precipitate with 50 ml of hot sulfuric acid (6.2). Add water to the beaker in order to obtain a volume of approximately

32、100 ml. Bring to a temperature of 70 C to 80 C and titrate drop by drop with a permanganate solution (6.9) until the pink colour lasts for a minute. This volume is v. 10 Calculation and expression of the result Calculate the calcium (Ca) content, wCa, in percent of the fertilizer analysed according

33、to Formula (1). mvvtvw=21Ca0,0240,200 (1) where BS EN 16196:2012EN 16196:2012 (E) 6 v is the volume of permanganate used, in millilitres; m is the mass of the test portion, in grams; v2is the aliquot volume, in millilitres; v1is the volume of the extraction solution, in millilitres; t is the substan

34、ce concentration of the permanganate solution in moles per litre. CaO (%) = Ca (%) 1,400 11 Precision 11.1 Inter-laboratory test Repeated inter-laboratory tests have been carried out in 2007 and 2009 with different numbers of participating laboratories and several different samples (see Table A.1 to

35、 Table A.4). Repeatability and reproducibility were calculated according to ISO 5725-2. The values derived from these inter-laboratory tests may not be applicable to concentration ranges and matrices other than those given in Annex A. 11.2 Repeatability The absolute difference between two independen

36、t single test results, obtained with the same method on identical test material in the same laboratory by the same operator using the same equipment within a short interval of time, will in not more than 5 % of the cases exceed the values of r given in Table 1 and Table 2. 11.3 Reproducibility The a

37、bsolute difference between two single test results, obtained with the same method on identical test material in different laboratories by different operators using different equipment, will in not more than 5 % of the cases exceed values of R given in Table 1 and Table 2. BS EN 16196:2012EN 16196:20

38、12 (E) 7 Table 1 Results ring test 2007 Sample Extraction methodx% r % R % CAN EN 15960 6,39 0,19 1,13 EN 15961 2,49 0,38 1,85 NPK1:23-4-13+7SO3 EN 15960 0,51 0,08 0,43 EN 15961 0,36 0,07 0,31 NPK2:12-11-18+2+8 EN 15960 3,49 0,15 1,20 EN 15961 0,53 0,10 0,49 Table 2 Results ring test 2009 Sample Ext

39、raction methodx% r % R % CAN EN 15960 6,20 0,25 1,2 EN 15961 2,61 0,19 4,05 NPK:12-12-17S+2 EN 15960 5,80 0,13 0,74 EN 15961 3,52 0,27 3,93 12 Test report The test report shall contain at least the following information: a) all information necessary for the complete identification of the sample; b)

40、the test method used with reference to this document; c) the method of preparation of the extraction solution (EN 15960 or EN 15961); d) the test results obtained; e) date of sampling and sampling procedure (if known); f) date when the analysis was finished; g) whether the requirement of the repeata

41、bility limit has been fulfilled; h) all operating details not specified in this document, or regarded as optional, together with details of any incidents occurred when performing the method, which might have influenced the test result(s). BS EN 16196:2012EN 16196:2012 (E) 8 Annex A (informative) Sta

42、tistical results of the inter-laboratory tests The precision of the method was established in 2007 and in 2009 by Working Group 7 “Chemical analysis” of CEN/TC 260 “Fertilizers and liming materials” in several inter-laboratory tests evaluated in accordance with ISO 5725-2. The statistical results ar

43、e given in Table A.1 to Table A.4. Table A.1 Statistical results of the inter-laboratory test in 2007 Extraction method EN 15960 Parameter Sample CAN NPK1:23-4-13+7SO3 NPK2:12-11-18+2+8 Number of participating laboratories 14 11 13 Number of laboratories after elimination of outliers (accepted test

44、results) 12 11 13 Mean value x (%) 6,39 0,51 3,49 Repeatability standard deviation sr(%) 0,07 0,03 0,06 RSDr(%) 1,1 6,0 1,6Repeatability limit r (%) 0,19 0,08 0,15 Reproducibility standard deviation sR(%) 0,40 0,15 0,43 RSDR(%) 6,3 30,0 12,3 Reproducibility limit R (%) 1,13 0,43 1,20Table A.2 Statis

45、tical results of the inter-laboratory test in 2007 Extraction method EN 15961 Parameter Sample CAN NPK1:23-4-13+7SO3 NPK2:12-11-18+2+8 Number of participating laboratories 14 10 12 Number of laboratories after elimination of outliers (accepted test results) 14 10 12 Mean value x (%) 2,49 0,36 0,53 R

46、epeatability standard deviation sr(%) 0,14 0,02 0,03 RSDr(%) 5,0 6,0 7,0Repeatability limit r (%) 0,38 0,07 0,10 Reproducibility standard deviation sR(%) 0,66 0,11 0,18 RSDR(%) 27,0 31,0 33,0 Reproducibility limit R (%) 1,85 0,31 0,49BS EN 16196:2012EN 16196:2012 (E) 9 Table A.3 Statistical results

47、of the inter-laboratory test in 2009 Extraction method EN 15960 Parameter Sample CAN NPK:12-12-17S+2 Number of participating laboratories 12 12 Number of laboratories after elimination of outliers (accepted test results) 12 10Mean value x (%) 6,20 5,80 Repeatability standard deviation sr(%) 0,09 0,0

48、5RSDr(%) 1,4 0,8 Repeatability limit r (%) 0,25 0,13Reproducibility standard deviation sR(%) 0,43 0,26 RSDR(%) 6,9 4,5Reproducibility limit R (%) 1,2 0,74 Table A.4 Statistical results of the inter-laboratory test in 2009 Extraction method EN 15961 Parameter Sample CAN NPK:12-12-17S+2 Number of part

49、icipating laboratories 12 12 Number of laboratories after elimination of outliers (accepted test results) 10 12Mean value x (%) 2,61 3,52 Repeatability standard deviation sr(%) 0,07 0,10RSDr(%) 3,0 3,0 Repeatability limit r (%) 0,19 0,27Reproducibility standard deviation sR(%) 1,45 1,40 RSDR(%) 55,0 40,0Reproducibility limit R (%) 4,05 3,93 BS EN 16196:2012EN 16196:2012 (E) 10 Bibliography 1 EN 1482-1, Fertilizers and liming materials Sampling and sample preparation Part