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1、BRITISH STANDARD BS EN 13466-1:2001 Fertilizers Determination of water content (Karl Fischer methods) Part 1: Methanol as extracting medium The European Standard EN 13466-1:2001 has the status of a British Standard ICS 65.080 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW Lic
2、ensed Copy: x x, The University of Sheffield, 28/06/2009 18:34, Uncontrolled Copy, (c) BSI BS EN 13466-1:2001 This British Standard, having been prepared under the direction of the Materials and Chemicals Sector Policy and Strategy Committee, was published under the authority of the Standards Policy
3、 and Strategy Committee on 10 April 2002 BSI 10 April 2002 ISBN 0 580 39472 7 National foreword This British Standard is the official English language version of EN 13466-1:2001. The UK participation in its preparation was entrusted to Technical Committee CII/37, Fertilizers and related chemicals, w
4、hich has the responsibility to: A list of organizations represented on this committee can be obtained on request to its secretary. Cross-references The British Standards which implement international or European publications referred to in this document may be found in the BSI Standards Catalogue un
5、der the section entitled “ International Standards Correspondence Index” , or by using the “ Find” facility of the BSI Standards Electronic Catalogue. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their corre
6、ct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. aid enquirers to understand the text; present to the responsible European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor
7、related international and European developments and promulgate them in the UK. Summary of pages This document comprises a front cover, an inside front cover, the EN title page, pages 2 to 10, an inside back cover and a back cover. The BSI copyright date displayed in this document indicates when the
8、document was last issued. Amendments issued since publication Amd. No. DateComments Licensed Copy: x x, The University of Sheffield, 28/06/2009 18:34, Uncontrolled Copy, (c) BSI EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 13466-1 October 2001 ICS 65.080 English version Fertilizers - Determi
9、nation of water content - (Karl Fischer methods) - Part 1: Methanol as extracting medium Engrais - Dtermination de la teneur en eau (Mthodes Karl Fischer) - Partie 1: Le mthanol comme milieu dextraction Dngemittel - Bestimmung des Wassergehaltes (Karl- Fischer-Verfahren) - Teil 1: Methanol als Extra
10、ktionsmittel This European Standard was approved by CEN on 18 August 2001. 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 without any alteration. Up-to-date lists and bibliog
11、raphical references concerning such national standards may be obtained on application to the 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 C
12、EN member into its own language and notified to the Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway,
13、Portugal, 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 2001 CENAll rights of exploitation in any form and by any means reserved worldwide for
14、CEN national Members. Ref. No. EN 13466-1:2001 E Licensed Copy: x x, The University of Sheffield, 28/06/2009 18:34, Uncontrolled Copy, (c) BSI EN 13466-1:2001 (E) 2 Contents page Foreword3 Introduction.4 1Scope 5 2Normative references 5 3Principle5 4Reagents.5 5Apparatus .5 6Installation and test of
15、 the Karl Fischer titrator6 7Sampling.6 8Procedure .6 9Calculation and expression of results.8 10Precision.9 11Test report 9 Bibliography10 Licensed Copy: x x, The University of Sheffield, 28/06/2009 18:34, Uncontrolled Copy, (c) BSI ? EN 13466-1:2001 (E) 3 Foreword This European Standard has been p
16、repared 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 April 2002, and conflicting n
17、ational standards shall be withdrawn at the latest by April 2002. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Gre
18、ece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom. Licensed Copy: x x, The University of Sheffield, 28/06/2009 18:34, Uncontrolled Copy, (c) BSI ? EN 13466-1:2001 (E) 4 Introduction The water content of fertilizers has a signif
19、icant effect on their quality and, especially, their storage and handling properties. Water can be present in a number of forms such as free water, bound water and water of crystallization. It is often important to be able to distinguish between these forms of water. The gravimetric methods for dete
20、rmination of water standardized in EN 12048 and EN 12049 have only limited applicability. The Karl Fischer method is applicable to a wide range of fertilizers. However, there are several variations to the basic technique, different formulations of the Karl Fischer reagents are commercially available
21、 and a number of different solvents can be used. In this standard, methanol and 2-propanol are used as extracting media to distinguish between the different forms of water present in fertilizers. EN 13466 “Fertilizers Determination of water content (Karl Fischer methods)“ consists of two parts: ?Par
22、t 1 : Methanol as extracting medium ?Part 2 : 2-propanol as extracting medium As examples of the difference between methanol and 2-propanol as extracting media methanol gives a result which is a combination of free water and extracted water of crystallization from the following components of fertili
23、zers: calcium nitrate tetrahydrate (Ca(NO3)24H2O); calcium hydrogen phosphate dihydrate (CaHPO42H2O); calcium sulfate dihydrate (gypsum, CaSO42H2O) calcium sulfate hemihydrate (CaSO40,5H2O); magnesium sulfate heptahydrate (MgSO47H2O); potassium chloride magnesium sulfate water (1/1/2,75, Kainite, KC
24、lMgSO42,75H2O); potassium magnesium sulfate hexahydrate (Schoenite, K2SO4MgSO46H2O); potassium magnesium sulfate tetrahydrate (Leonite, K2SO4MgSO44H2O); potassium sulfate calcium sulfate monohydrate (Syngenite, K2SO4CaSO4H2O); potassium chloride magnesium chloride hexahydrate (Carnallite, KCl MgCl26
25、H2O); magnesium nitrate hexahydrate (Mg(NO3)26H2O). Extraction with 2-propanol gives a result which is a combination of free water and extracted water of crystallization from the following components of fertilizers: calcium nitrate tetrahydrate (Ca(NO3)24H2O); magnesium sulfate heptahydrate (MgSO47H
26、2O); potassium chloride magnesium chloride hexahydrate (Carnallite, KClMgCl26H2O); magnesium nitrate hexahydrate (Mg(NO3)26H2O). Licensed Copy: x x, The University of Sheffield, 28/06/2009 18:34, Uncontrolled Copy, (c) BSI ? EN 13466-1:2001 (E) 5 1 Scope This European Standard specifies a Karl Fisch
27、er titrimetric method for the determination of the water content of fertilizers based on the use of methanol as extracting medium. The method is applicable to all solid mineral fertilizers. The result (KFM water) includes “free“ water and extracted water of crystallization from the following compone
28、nts of fertilizers: calcium nitrate tetrahydrate (Ca(NO3)24H2O); calcium hydrogen phosphate dihydrate (CaHPO42H2O); calcium sulfate dihydrate (gypsum, CaSO42H2O), calcium sulfate hemihydrate (CaSO40,5H2O); magnesium sulfate heptahydrate (MgSO47H2O) ; potassium chloride magnesium sulfate water (1/1/2
29、,75, Kainite, KClMgSO42,75H2O); potassium magnesium sulfate hexahydrate (Schoenite, K2SO4MgSO46H2O); potassium magnesium sulfate tetrahydrate (Leonite, K2SO4MgSO44H2O); potassium sulfate calcium sulfate monohydrate (Syngenite, K2SO4CaSO4H2O); potassium chloride magnesium chloride hexahydrate (Carnal
30、lite, KClMgCl26H2O); magnesium nitrate hexahydrate (Mg(NO3)26H2O). Metal oxides and hydroxides soluble in methanol and pyridine will have an effect which can be corrected for, if their content is known. 2 Normative references This European Standard incorporates by dated or undated reference, provisi
31、ons from other publications. These normative references are cited at the appropriate places in the text, and the publications are listed hereafter. For dated references, subsequent amendments to or revisions of any of these publications apply to this European Standard only when incorporated in it by
32、 amendment or revision. For undated references the latest edition of the publication referred to applies (including amendments). EN 1482, Sampling of solid fertilizers and liming materials. 3 Principle Extraction of water from the fertilizer into methanol and titration of the water with a Karl Fisch
33、er reagent, previously standardized by titration with a known mass of water. 4 Reagents 4.1 General All reagents shall be of recognized analytical grade. 4.2Methanol, containing no more than a mass concentration of 500 mg/l water. 4.3Karl Fischer reagent, equivalence from 1 mg to 5 mg water/ml reage
34、nt (see Tables 1 and 2). 4.4Sodium tartrate dihydrate Na2C4H4O6 2H2O (15,66 % mass fraction of water). Sodium tartrate dihydrate Na2C4H4O6 2H2O can be stored over 60 % H2SO4in a desiccator. Check the water content by drying at about 150 C. 5 Apparatus Ordinary laboratory apparatus and glassware and
35、in particular the following: 5.1Balance, capable of weighing to the nearest 0,0001 g. Licensed Copy: x x, The University of Sheffield, 28/06/2009 18:34, Uncontrolled Copy, (c) BSI ? EN 13466-1:2001 (E) 6 5.2Mortar and pestle. 5.3Centrifuge capable of operating at a rate of 3 500 min-1. 5.4 Centrifug
36、e tubes, diameter 4,5 cm, height 10 cm fitted with rubber stoppers. 5.5 Dispersing apparatus : turbine type, minimum rotational frequency 9 500 min-1, suitable for introduction into centrifuge tubes (5.4), for instance Ultra Turrax?1 5.6 Karl Fischer titrator NOTEThere are several titrators on the m
37、arket for the Karl Fischer method. 6 Installation and test of the Karl Fischer titrator Follow the instruction manual for the particular titrator used. 7 Sampling Carry out sampling in accordance with EN 1482. 8 Procedure 8.1 Calibration of the Karl Fischer reagent Titrate a known amount of water or
38、 sodium tartrate dihydrate (4.4) accurately weighed to the nearest 0,0001 g following the instruction manual for the titrator. NOTECalibration frequency should be adapted to the frequency of analysis. 8.2 Drift Control the diffusion of water from the air into the titration vessel during the determin
39、ation following the Instruction Manual for the titrator. Take account of any recorded drift (md) when expressing results. 8.3 Determination 8.3.1 General If the fertilizer is dispersible in methanol (4.2), the extraction and titration can be carried out in the titration vessel (see 8.3.2). If not, a
40、 separate extraction step will be needed (see 8.3.3). Urea, ammonium nitrate and CAN (= calcium ammonium nitrate) are usually dispersible in methanol. 8.3.2 Fertilizers dispersible or soluble in methanol 8.3.2.1 Preparation of test portion Rapidly crush the test sample prepared in accordance with cl
41、ause 7 and immediately weigh a test portion (see Table 1) to the nearest 0,0001g. 1 Ultra Turrax S25? equipped with dispersing turbine S25KR - 18G is an example of equipment commercially available. This information is given for the convenience of users of this European Standard and does not constitu
42、te an endorsement by CEN of these products. Licensed Copy: x x, The University of Sheffield, 28/06/2009 18:34, Uncontrolled Copy, (c) BSI ? EN 13466-1:2001 (E) 7 NOTEProducts such as urea and ammonium nitrate which are fully soluble in methanol should not be crushed. Table 1 Mass of test portion for
43、 fertilizers dispersible or soluble in methanol Mass of test portionExpected water content mass fraction in % titre of KF-Reagent 5 mg/ml titre of KF-Reagent 2 mg/ml 20 to 500,2 g- 8.3.2.2 Titration Introduce 20 ml of methanol (4.2) into the reaction vessel of the titrator (5.6). Introduce the weigh
44、ed test portion (8.3.2.1) directly into the reaction vessel of the titrator (5.6). Start stirring and ensure, that the grains of the fertilizer are fully dispersed. Titrate with the Karl Fischer reagent (4.3) until the equivalence point is reached following the instruction manual for the titrator. R
45、ecord the mass ms, in milligrams of water, indicated by the titrator. Adapt the dead-time of the titrator to the grain size of the dispersed fertilizer in accordance with the instruction manual of the titrator used. 8.3.3 Fertilizers not dispersible in methanol 8.3.3.1 Test portion Weigh a test port
46、ion of the test sample, in accordance with clause 7 and Table 2 to the nearest 0,0001 g directly into the previously dried and tared centrifuge tube (5.4). Table 2 Mass of test portion for fertilizers not dispersible in methanol Mass of test portionExpected water content mass fraction in % titre of
47、KF-Reagent 5 mg/ml titre of KF-Reagent 2 mg/ml 20 to 50-1 g 8.3.3.2 Extraction Add 25 ml of methanol (4.2) with a calibrated pipette to the test portion in the centrifuge tube. Insert the dispersing apparatus (5.5) ensuring that the distance from any part of the dispersing tool to the inner surface
48、of the centrifuge tube is greater than the grain size of the fertilizer. Place the dispersing tool near to the surface of the fertilizer layer. Disperse for 60 s at room temperature at 9 500 min-1at least. Make sure that the temperature during the dispersion-extraction does not exceed 40 C or, in ca
49、se of fertilizer containing magnesium sulfate, 25 C. Repeat the dispersion for a further 60 s if the fertilizer has not been completely dispersed in the first operation. Repeat the extraction if the dispersion is still not complete. NOTEThe dispersion can be controlled acoustically; the turbine pitch changes once the dispersion is complete. Licensed Copy: x x, The University of Sheffield, 28/06/2009 18:34, Uncontrolled Copy, (c) BSI ?