BS EN 15489-2007 Ethanol as a blending component for petrol - Determination of water content - Karl Fischer coulometric titration method《作为汽油混合组分之一的乙醇 含水量的测定 卡耳费瑟库仑滴定法》.pdf

《BS EN 15489-2007 Ethanol as a blending component for petrol - Determination of water content - Karl Fischer coulometric titration method《作为汽油混合组分之一的乙醇 含水量的测定 卡耳费瑟库仑滴定法》.pdf》由会员分享，可在线阅读，更多相关《BS EN 15489-2007 Ethanol as a blending component for petrol - Determination of water content - Karl Fischer coulometric titration method《作为汽油混合组分之一的乙醇 含水量的测定 卡耳费瑟库仑滴定法》.pdf（12页珍藏版）》请在麦多课文档分享上搜索。

1、Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 12/12/2007 02:36, Uncontrolled Copy, (c) BSIg49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58c

2、ontent Karl Fischer coulometric titration methodThe European Standard EN 15489:2007 has the status of a British StandardICS 71.080.60Ethanol as a blending component for petrol Determination of water BRITISH STANDARDBS EN 15489:2007 BS 2000-539:2007BS EN 15489:2007Licensed Copy: Wang Bin, ISO/EXCHANG

3、E CHINA STANDARDS, 12/12/2007 02:36, Uncontrolled Copy, (c) BSIThis BritiThe PTArequest to its EnBSThis British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 October 2007 BSI and Energy Institute 2007ISBN 978 0 580 56677 6Compliance with a British St

4、andard cannot confer immunity from legal obligations. Amendments issued since publicationAmd. No. Date Commentsboth in its annual publication “Standard methods for analysis and testing of petroleum and related products and British Standard 2000 Parts” and individually.Further information is availabl

5、e from: Energy Institute, 61 New Cavendish Street, London W1G 7AR. Tel: 020 7467 7100. Fax: 020 7255 1472.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application.National forewordsh Standard is the UK implementation o

6、f EN 15489:2007.UK participation in its preparation was entrusted to Technical Committee I/13, Petroleum testing and terminology.list of organizations represented on this committee can be obtained on secretary.ergy Institute, under the brand of IP, publishes and sells all Parts of 2000, and all BS E

7、N petroleum test methods that would be Part of BS 2000, EUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN 15489August 2007ICS 71.080.60English VersionEthanol as a blending component for petrol - Determination ofwater content - Karl Fischer coulometric titration methodEthanol comme base de mlange les

8、sence -Dtermination de la teneur en eau - Mthode de titragecoulomtrique Karl FischerEthanol zur Verwendung als Blendkomponente inOttokraftstoff - Bestimmung des Wassergehaltes -Coulometrisches Titrationsverfahren nach Karl FischerThis European Standard was approved by CEN on 30 June 2007.CEN members

9、 are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving 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

10、 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 translationunder the responsibility of a CEN member into its own language and notified to the CEN Management Centre has the same

11、 status as theofficial 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,Romani

12、a, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGManagement Centre: rue de Stassart, 36 B-1050 Brussels 2007 CEN All rights of exploitation in any form and by any means reservedworld

13、wide for CEN national Members.Ref. No. EN 15489:2007: ELicensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 12/12/2007 02:36, Uncontrolled Copy, (c) BSIEN 15489:2007 (E) 2 Contents Page Foreword. 3 1 Scope 4 2 Normative references . 4 3 Terms and definitions. 4 4 Principle . 4 5 Reagents and mater

14、ials 4 6 Apparatus 5 7 Sampling and sample handling . 5 8 Apparatus preparation 5 9 Apparatus verification 6 10 Procedure 6 11 Calculation. 7 12 Expression of results 7 13 Precision 7 13.1 General. 7 13.2 Repeatability, r 7 13.3 Reproducibility, R . 7 14 Test report . 8 Bibliography . 9 Licensed Cop

15、y: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 12/12/2007 02:36, Uncontrolled Copy, (c) BSIEN 15489:2007 (E) 3 Foreword This document (EN 15489:2007) has been prepared by Technical Committee CEN/TC 19 “Gaseous and liquid fuels, lubricants and related products of petroleum, synthetic and biological origi

16、n”, the secretariat of which is held by NEN. 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 February 2008, and conflicting national standards shall be withdrawn at the latest by February 2008. Th

17、is document was prepared by CEN/TC 19s Ethanol Task Force and is based on the Energy Institute standard IP 539 1. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgar

18、ia, 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. . Licensed Copy: Wang Bin, ISO/EX

19、CHANGE CHINA STANDARDS, 12/12/2007 02:36, Uncontrolled Copy, (c) BSIEN 15489:2007 (E) 4 1 Scope This European Standard specifies a method for the direct determination of water in ethanol to be used in gasoline blends. It is applicable to ethanol having water contents in the range 0,039 % (m/m) to 0,

20、500 % (m/m). NOTE For the purposes of this document, the term “% (m/m)” is used to represent the mass fraction. WARNING Use of this standard may involve hazardous materials, operations and equipment. This standard does not purport to address all of the safety problems associated with its use. It is

21、the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated ref

22、erences, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN ISO 3170, Petroleum liquids Manual sampling (ISO 3170:2004) EN ISO 3696, Water for analytical laboratory use Specification and test methods (ISO 3696:

23、1987) 3 Terms and definitions For the purposes of this European Standard, the following terms and definitions apply. 3.1 water content content of water determined by coulometric Karl Fischer procedure as given in this document 4 Principle A weighed test portion is injected into the titration vessel

24、of a coulometric Karl Fischer apparatus in which iodine for the Karl Fischer reaction is generated coulometrically at the anode. When all the water has been titrated, excess iodine is detected by an electrometric end-point detector and the titration is terminated. Based on the stoichiometry of the r

25、eaction, one mole of iodine reacts with one mole of water, thus the quantity of water is proportional to the total integrated current according to Faradays Law. 5 Reagents and materials Use only reagents of recognized analytical grade and water complying with the requirements of grade 3 of EN ISO 36

26、96. 5.1 Xylene, water free Remove dissolved water from the xylene by adding approximately 100 g of activated molecular sieve (5.3) to approximately 2 l of xylene. Allow to stand overnight. Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 12/12/2007 02:36, Uncontrolled Copy, (c) BSIEN 15489:200

27、7 (E) 5 5.2 Karl Fischer reagent, pyridine free. Use commercially available reagents that meet the performance requirements described in clause 9. 5.2.1 Anode electrolyte solution (anolyte) 5.2.2 Cathode electrolyte solution (catholyte) 5.2.3 Single Karl Fischer Reagents, for use in place of dual el

28、ectrolyte solutions (5.2.1 and 5.2.2) in cells with or without a diaphragm. 5.3 Molecular sieve pellets Activate by placing in an oven at 200 C to 250 C for 4 h. Remove from the oven and transfer immediately to either a dry glass bottle fitted with a gas-tight closure or a desiccator. Allow to cool

29、before use. 6 Apparatus 6.1 Automatic coulometric Karl Fischer titrator, capable of meeting the requirements given in clause 9. 6.2 Syringes, of glass, with needles of suitable length such that the tip can reach under the surface of the anolyte when inserted through the inlet-port septum. The bores

30、of the needles used shall be kept as small as possible, but large enough to avoid problems arising from back pressure or blocking whilst sampling. NOTE 1 Needles with bores between 0,5 mm and 0,8 mm have been found suitable. NOTE 2 Recommended syringe sizes are: a) 10 l with a fixed needle for perio

31、dic checking of the titrator performance, and b) 1 ml or 2 ml for the ethanol test portion. 6.3 Balance, capable of weighing to 0,1 mg. 7 Sampling and sample handling 7.1 Samples shall be taken as described in EN ISO 3170. 7.2 Take care to minimise the uptake of atmospheric moisture during sampling

32、and sample handling. NOTE The use of a glass bottle that can be sealed with a septum has been found suitable for sampling and sample handling. A test portion of the sample can be taken through the septum with a syringe fitted with a needle. 8 Apparatus preparation 8.1 Follow the manufacturers direct

33、ions for preparation and operation of the titration apparatus. 8.2 Seal all joints and connections to the titration cell to prevent atmospheric moisture from entering. 8.3 If a single Karl Fischer solution (5.2.3) is used, add this solution to the cell. 8.4 If separate electrolyte solutions are used

34、, add the anolyte (5.2.1) to the outer compartment of the titration cell to the level recommended by the manufacturer. Add the catholyte (5.2.2) to the inner compartment of the titration cell to a level 2 mm to 3 mm below the level of the anolyte. Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARD

35、S, 12/12/2007 02:36, Uncontrolled Copy, (c) BSIEN 15489:2007 (E) 6 8.5 Turn on the titrator and stirrer. Allow the residual moisture in the titration cell to be titrated until the end-point is reached. Do not proceed beyond this stage until the background current (or background titration rate) is co

36、nstant and less than the maximum recommended by the manufacturer of the instrument. NOTE High background current for a prolonged period can be attributable to moisture on the inside walls of the titration cell. Gentle swirling of the cell will wash the inside with electrolyte. Also check all fitting

37、s to ensure atmospheric moisture does not enter the cell. It is recommended that the titrator be permanently switched on to stabilize to a low background current. 8.6 If the vessel becomes contaminated with a previously tested organic sample, thoroughly clean the anode and cathode compartments with

38、xylene (5.1). If the frit becomes blocked, thoroughly clean with xylene. Do not use acetone or other ketones for cleaning or drying the apparatus. 9 Apparatus verification The water titrated is a direct function of the coulombs of electricity consumed. However, reagent performance deteriorates with

39、use and shall be regularly monitored by accurately injecting 10 l of water. Suggested monitoring intervals are done initially when fresh reagents are used and then after every 10 injections. Replace the anolyte (5.2.1) and catholyte (5.2.2) solutions, or the single Karl Fischer solution (5.2.3), whe

40、never one of the following occurs: a) result from a 10 l injection of water is outside 10 000 g 200 g, or persistently high; b) unstable background current, or phase separation in the outer compartment, or organic products coating the electrodes; c) total sample content of the titration cell exceeds

41、 one third of the volume of the anolyte; d) titrator displays error messages which suggests replacing the electrolytes (see the manufacturers instructions). 10 Procedure 10.1 Using a clean, dry syringe (6.2) to withdraw at least three portions of the sample and discard as waste. Immediately withdraw

42、 a 1 ml to 2 ml test portion of the sample, clean the needle with a paper tissue and using the balance (6.3) weigh the syringe and contents to the nearest 0,1 mg. 10.2 Insert the needle through the inlet-port septum, start the titration and, with the tip of the needle just below the liquid surface,

43、inject the entire test portion. Withdraw the syringe, wipe the needle with a clean tissue, and reweigh the syringe to the nearest 0,1 mg. 10.3 The apparatus will automatically titrate the water present. After the end-point is reached, record the water titrated from the display on the titrator (6.1).

44、 Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 12/12/2007 02:36, Uncontrolled Copy, (c) BSIEN 15489:2007 (E) 7 11 Calculation Calculate the water content of the sample, Cs, expressed in % (m/m), using the following equation: 412s10=mmC (1) where m1is the mass of the test portion, expressed

45、in grams; m2 is the mass of water displayed by the titrator, expressed in micrograms. 12 Expression of results Report the water content of the sample to the nearest 0,001 % (m/m). 13 Precision 13.1 General The precision given was derived from statistical analysis by EN ISO 4259 2 of the results of i

46、nterlaboratory testing of a matrix of ethanol samples produced in Europe from bio materials such as raw wine, molasses, pulp and corn. NOTE The interlaboratory testing and the statistical evaluation are detailed in Research Report: IP 539 2. 13.2 Repeatability, r The difference between two test resu

47、lts, obtained by the same operator with the same apparatus under constant operating conditions on identical test material would in the long run, in the normal and correct operation of the test method, exceed the following value in only one case in twenty. r = 0,011 16 (X + 1) (2) where X is the aver

48、age of results being compared. Typical values are given in Table 1. 13.3 Reproducibility, R The difference between two single and independent results, obtained by different operators working in different laboratories on identical test material, would in the long run, in the normal and correct operat

49、ion of the test method, exceed the following value only in one case in twenty. R = 0,018 80 (X + 1) (3) where X is the average of results being compared. Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 12/12/2007 02:36, Uncontrolled Copy, (c) BSIEN 15489:2007 (E) 8 Typical values are given in Table 1. Table 1 Typical precision values Water % (m/m) Repeatability r Reproducibility R 0,020 0,011 4 0,019 2 0,050 0,011 7 0,019 7 0,100 0,012 3 0,020 7 0,200 0,013 4 0,022 6 0,300 0,014 5 0,024 4 0,500 0,016 7 0,028 2 14 Test report The test repor