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1、DRAFT FOR DEVELOPMENT DD CEN/TS 15477:2006 Fertilizers Determination of the water-soluble potassium content ICS 65.080 ? Licensed Copy: London South Bank University, London South Bank University, Sun Dec 24 04:41:12 GMT+00:00 2006, Uncontrolled Copy, (c) BSI DD CEN/TS 15477:2006 This Draft for Devel
2、opment was published under the authority of the Standards Policy and Strategy Committee on 29 December 2006 BSI 2006 ISBN 0 580 49799 2 National foreword This Draft for Development was published by BSI. It is the UK implementation of CEN/TS 15477:2006. This publication is not to be regarded as a Bri
3、tish Standard. It is being issued in the Draft for Development series of publications and is of a provisional nature. It should be applied on this provisional basis, so that information and experience of its practical application can be obtained. Comments arising from the use of this Draft for Devel
4、opment are requested so that UK experience can be reported to the European organization responsible for its conversion to a European standard. A review of this publication will be initiated not later than 3 years after its publication by the European organization so that a decision can be taken on i
5、ts status. Notification of the start of the review period will be made in an announcement in the appropriate issue of Update Standards. According to the replies received by the end of the review period, the responsible BSI Committee will decide whether to support the conversion into a European Stand
6、ard, to extend the life of the Technical Specification or to withdraw it. Comments should be sent to the Secretary of the responsible BSI Technical Committee at British Standards House, 389 Chiswick High Road, London W4 4AL. The UK participation in its preparation was entrusted to Technical Committe
7、e CII/37, Fertilisers and related chemicals. A list of organizations represented on CII/37 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. Amendments issued since
8、publication Amd. No. DateComments Licensed Copy: London South Bank University, London South Bank University, Sun Dec 24 04:41:12 GMT+00:00 2006, Uncontrolled Copy, (c) BSI TECHNICAL SPECIFICATION SPCIFICATION TECHNIQUE TECHNISCHE SPEZIFIKATION CEN/TS 15477 September 2006 ICS 65.080 English Version F
9、ertilizers - Determination of the water-soluble potassium content Engrais - Dtermination de la teneur en potassium soluble dans leau Dngemittel - Bestimmung von wasserlslichem Kalium This Technical Specification (CEN/TS) was approved by CEN on 24 June 2006 for provisional application. The period of
10、validity of this CEN/TS is limited initially to three years. After two years the members of CEN will be requested to submit their comments, particularly on the question whether the CEN/TS can be converted into a European Standard. CEN members are required to announce the existence of this CEN/TS in
11、the same way as for an EN and to make the CEN/TS available promptly at national level in an appropriate form. It is permissible to keep conflicting national standards in force (in parallel to the CEN/TS) until the final decision about the possible conversion of the CEN/TS into an EN is reached. CEN
12、members are the national standards bodies of Austria, Belgium, 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, Switze
13、rland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: rue de Stassart, 36 B-1050 Brussels 2006 CENAll rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No.
14、CEN/TS 15477:2006: E Licensed Copy: London South Bank University, London South Bank University, Sun Dec 24 04:41:12 GMT+00:00 2006, Uncontrolled Copy, (c) BSI 2 Contents Page Foreword3 1 Scope 4 2 Normative references4 3 Terms and definitions .4 4 Principle4 5 Reagents.4 6 Apparatus .5 7 Sampling an
15、d sample preparation.5 8 Procedure .6 9 Calculation and expression of the result 7 10 Precision.8 11 Test report9 Annex A (informative) Results of the inter-laboratory tests.10 Bibliography11 CEN/TS 15477:2006 Licensed Copy: London South Bank University, London South Bank University, Sun Dec 24 04:4
16、1:12 GMT+00:00 2006, Uncontrolled Copy, (c) BSI 3 Foreword This document (CEN/TS 15477:2006) has been prepared by Technical Committee CEN/TC 260 “Fertilizers and liming materials”, the secretariat of which is held by DIN. This document has been prepared under a mandate given to CEN by the European C
17、ommission and the European Free Trade Association. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to announce this Technical Specification: Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germa
18、ny, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. CEN/TS 15477:2006 Licensed Copy: London South Bank University, London South Bank University, Sun
19、Dec 24 04:41:12 GMT+00:00 2006, Uncontrolled Copy, (c) BSI 4 1 Scope This Technical Specification specifies a method for the determination of water-soluble potassium, which is applicable to all potassium fertilizers listed in Annex I of the Regulation (EC) No 2003/2003 1. 2 Normative references The
20、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. prEN 1482-2, Fertilizers and liming materials Samplin
21、g and sample preparation Part 2: Sample preparation EN 12944-1:1999, Fertilizers and liming materials Vocabulary Part 1: General terms EN 12944-2:1999, Fertilizers and liming materials Vocabulary Part 2: Terms relating to fertilizers (including corrigendum AC:2000) EN ISO 3696:1995, Water for analyt
22、ical 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 The potassium in the sample to be analyzed is dissolved in water. After eliminating
23、or fixing the substances that might interfere with the quantitative determination, the potassium is precipitated in a slightly alkaline medium in the form of potassium tetraphenylborate. 5 Reagents 5.1 General Use only reagents of recognized analytical grade and distilled or demineralized water (gra
24、de 3 according to EN ISO 3696:1995). 5.2 Formaldehyde clear formaldehyde solution with a mass fraction of 25 % to 35 % formaldehyde 5.3 Potassium chloride p. a. 5.4 Sodium hydroxide solution c = 10 mol/l Care should be taken to ensure that only potassium free sodium hydroxide is used. CEN/TS 15477:2
25、006 Licensed Copy: London South Bank University, London South Bank University, Sun Dec 24 04:41:12 GMT+00:00 2006, Uncontrolled Copy, (c) BSI 5 5.5 Indicator solution Dissolve 0,5 g of phenolphthalein in ethanol at 90 % and make the volume up to 100 ml. 5.6 EDTA solution Dissolve 4 g of the dihydrat
26、ed disodium salt of ethylenediaminetetraacetic acid in water in a 100 ml graduated flask. Make up the volume and mix. Store the reagent in a plastics container. 5.7 STPB solution Dissolve 32,5 g of sodium tetraphenylborate in 480 ml of water, add 2 ml of the sodium hydroxide solution (5.4) and 20 ml
27、 of a magnesium chloride solution (100 g of MgCl2 6H2O per litre). Stir for 15 min and filter through a fine, ashless filter. Store this reagent in a plastics container. 5.8 Liquid for washing Dilute 20 ml of the STPB solution (5.7) to 1 000 ml with water. 5.9 Bromine water saturated bromine solutio
28、n in water 6 Apparatus 6.1 Graduated flasks capacity 1 000 ml 6.2 250 ml and 600 ml beaker 6.3 Filter crucibles porosity 5 m to 20 m 6.4 Oven Regulated at (120 10) C 6.5 Desiccator 7 Sampling and sample preparation Sampling is not part of the method specified in this document. A recommended sampling
29、 method is given in prEN 1482-1. Sample preparation shall be carried out in accordance with prEN 1482-2. Grinding is recommended for homogeneity reasons. CEN/TS 15477:2006 Licensed Copy: London South Bank University, London South Bank University, Sun Dec 24 04:41:12 GMT+00:00 2006, Uncontrolled Copy
30、, (c) BSI 6 8 Procedure 8.1 Test portion Weigh to the nearest 0,001 g 10 g of the prepared sample (5 g for potassium salts with a mass fraction of potassium oxide of more than 50 %). Place this test portion in a 600 ml beaker with approximately 400 ml of water. Bring to a boil and allow it to boil f
31、or 30 min. Cool, transfer quantitatively into a 1 000 ml graduated flask, make up the volume, mix and filter into a dry receiver. Discard the first 50 ml of the filtrate (see 8.6). 8.2 Preparation of the aliquot part for precipitation Transfer by pipette an aliquot part of the filtrate containing 25
32、 mg to 50 mg of potassium (see Table 1) and place it in a 250 ml beaker. If required make up to 50 ml with water. To remove any interference, add 10 ml of the EDTA solution (5.6), several drops of the phenolphtalein solution (5.5) and stir in, drop by drop, sodium hydroxide solution (5.4) until it t
33、urns red, then finally add a few more drops of sodium hydroxide to ensure an excess (usually 1 ml of sodium hydroxide is sufficient to neutralize the sample and ensure an excess). To eliminate most of the ammonia, (see 8.6) boil gently for 15 min. If necessary, add water to make the volume up to 60
34、ml. Bring the solution to the boil, remove the beaker from the heat and add 10 ml of formaldehyde (5.2). Add several drops of phenolphtalein and, if necessary, some more sodium hydroxide until a distinct red colour appears. Cover the beaker with a watch glass and place it on a steam bath for 15 min.
35、 8.3 Weighing the crucible Dry the filter crucible to a constant mass (about 15 min) in the oven at 120 C. Allow the crucible to cool in a desiccator and then weigh it. 8.4 Precipitation Remove the beaker from the steam bath, stir in drop-by-drop 10 ml of the STPB solution (5.7). This addition takes
36、 about 2 min. Wait for at least 10 min before filtering. 8.5 Filtering and washing Filter under vacuum into the weighed crucible, rinse the beaker with the liquid for washing (5.8), wash the precipitate three times with the liquid for washing (60 ml in all of the liquid for washing), and twice with
37、5 ml to 10 ml of water. Dry the precipitate thoroughly. 8.6 Drying and weighing Wipe the outside of the crucible with a filter paper. Place the crucible with its contents in the oven for 1,5 h at 120 C. Allow the crucible to cool in a desiccator to ambient temperature and weigh immediately. If the f
38、iltrate is dark in colour, transfer by pipette, an aliquot part containing at the most, 100 mg of K2O and place in a 100 ml graduated flask. Add bromine water (5.9) and bring to a boil to eliminate any surplus bromine. After cooling make up the volume, filter and quantitatively determine the potassi
39、um in an aliquot part of the filtrate. CEN/TS 15477:2006 Licensed Copy: London South Bank University, London South Bank University, Sun Dec 24 04:41:12 GMT+00:00 2006, Uncontrolled Copy, (c) BSI 7 Where there is little or no ammoniacal nitrogen present there is no need to boil for 15 min. 8.7 Aliquo
40、t parts to be taken as samples and conversion factors Table 1 Aliquot parts and conversion factors K2O in the fertilizer % K in the fertilizer % Sample for analysis g Sample of the extract solution for the dilution ml Dilution to ml Aliquot part to be taken as a sample for precipitation ml Conversio
41、n factor F TPBKg OK%2 Conversion factor F TPBKg K% 5 - 10 4,2 8,3 10 - - 50 26,280 21,812 10 - 20 8,3 16,6 10 - - 25 52,560 43,624 20 - 50 16,6 41,5 10 either or 50 250 10 50 131,400 131,400 109,060 109,060 more than 50 more than 41,5 5 either or 50 - 250 10 50 262,800 262,800 218,120 218,120 8.8 Bl
42、ank test For each series of determinations, carry out a blank test using only the reagents in the proportions used in the analysis and allow for this when calculating the final result. 8.9 Control test In order to obtain a control for the Method of analysis, carry out a determination on an aliquot p
43、art of an aqueous solution of potassium chloride, containing at the most 40 mg of K2O. 9 Calculation and expression of the result 9.1 Dilution according to Table 1 Calculate the K2O content, OK2 w, as mass fraction in percent of the fertilizer according to equation (1): Fmmw=)( 21OK2 (1) CEN/TS 1547
44、7:2006 Licensed Copy: London South Bank University, London South Bank University, Sun Dec 24 04:41:12 GMT+00:00 2006, Uncontrolled Copy, (c) BSI 8 Calculate the K content, wK, as mass fraction in percent of the fertilizer according to equation (2): )( 21K Fmmw= (2) where m1 is the mass of the precip
45、itate from the sample, in grams; m2 is the mass of the precipitate from the blank, in grams; F and F conversion factors (see Table 1). 9.2 Dilution different from Table 1 Calculate the K2O content, OK2 w, as mass fraction in percent of the fertilizer according to equation (3): m Dmm w 100F)( 21 OK2
46、= (3) Calculate the K content, wK, as mass fraction in percent of the fertilizer according to equation (4): m Dmm w 100 F)( 21 K = (4) where m1 is the mass of the precipitate from the sample, in grams; m2 is the mass of the precipitate from the blank, in grams; F conversion factor, KTPB into K2O = 0
47、,1314; F conversion factor, KTPB into K = 0,109; D dilution factor; m is the mass of the sample for analysis (test portion), in grams. 10 Precision 10.1 Inter-laboratory test An inter-laboratory test was carried out in 2004 with 16 participating laboratories and two different samples of fertilizers
48、and phosphate types. This test yielded the data given in Annex A. Repeatability and reproducibility were calculated according to ISO 5725-1. The values derived from this inter-laboratory test might not be applicable to concentration ranges and matrices other than those given in Annex A. 10.2 Repeata
49、bility The absolute difference between two independent 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 2. CEN/TS 15477:2006 Licensed Copy: London South Bank University, London South Bank University, Sun Dec 24 04:41:12 GMT+00:00 2006, Uncontrolled