1、BS EN 15692:2009BS 2000-572:2009ICS 71.080.60,75.160.20NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBRITISH STANDARDEthanol as a blending component for petrol Determination of water content Karl Fischer potentiometric titration methodLicensed Copy: Wang Bin, ISO/EXCHANGE CHI
2、NA STANDARDS, 16/11/2009 07:53, Uncontrolled Copy, (c) BSIThis British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 July 2009 BSI 2009ISBN 978 0 580 58753 5Amendments/corrigenda issued since publicationDate CommentsBS EN 15692:2009National forewordT
3、his British Standard is the UK implementation of EN 15692:2009.The UK participation in its preparation was entrusted to Technical Committee PTI/13, Petroleum testing and terminology.A list of organizations represented on this committee can be obtained on request to its secretary.This publication doe
4、s not purport to include all the necessary provisions of a contract. Users are responsible for its correct application.Compliance with a British Standard cannot confer immunity from legal obligations.Energy Institute, under the brand of IP, publishes and sells all Parts of BS 2000, and all BS EN pet
5、roleum test methods that would be Part of BS 2000, both 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 available from: Energy Institute, 61 New Cavendish Street, London W1
6、G 7AR.Tel: 020 7467 7100. Fax: 020 7255 1472.Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 16/11/2009 07:53, Uncontrolled Copy, (c) BSIBS EN 15692:2009EUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN 15692April 2009ICS 75.160.20English VersionEthanol as a blending component for petrol - De
7、termination ofwater content - Karl Fischer potentiometric titration methodEthanol comme base de mlange lessence -Dtermination de la teneur en eau - Mthode de titragepotentiomtrique Karl FischerEthanol zu Verwendung als Blendkomponente inOttokraftstoff - Bestimmung des Wassergehaltes -Potentiometrisc
8、he Titration nach Karl FischerThis European Standard was approved by CEN on 19 March 2009.CEN members 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 lis
9、ts 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 versions (English, French, German). A version in any other language made by translationunder the respon
10、sibility 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, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,France, Germany, Greece, Hungary, Icelan
11、d, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGManagement Centre: Avenue Marnix
12、 17, B-1000 Brussels 2009 CEN All rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN 15692:2009: ELicensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 16/11/2009 07:53, Uncontrolled Copy, (c) BSIBS EN 15692:2009EN 15692:2009 (E) 2 Contents Pa
13、ge Foreword 3 1 Scope 4 2 Normative references 4 3 Terms and definitions .4 4 Principle 4 5 Reagents and materials 4 6 Apparatus .5 7 Sampling and sample handling 5 8 Procedure .6 8.1 Standardization of the Karl Fischer reagent .6 8.2 Analysis 6 9 Calculation 7 10 Expression of results 7 11 Precisio
14、n .7 11.1 General 7 11.2 Repeatability, r .8 11.3 Reproducibility, R 8 12 Test report 8 Bibliography 9 Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 16/11/2009 07:53, Uncontrolled Copy, (c) BSIBS EN 15692:2009EN 15692:2009 (E) 3 Foreword This document (EN 15692:2009) has been prepared by Te
15、chnical Committee CEN/TC 19 “Gaseous and liquid fuels, lubricants and related products of petroleum, synthetic and biological origin”, 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 en
16、dorsement, at the latest by October 2009, and conflicting national standards shall be withdrawn at the latest by October 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 id
17、entifying any or all such patent rights. This document was prepared by CEN/TC 19s Ethanol Task Force under its Working Group 21 and is based on ISO 760 1. It is developed as an alternative to EN 15489 2, delivering a method more widely used in the alcohol and beverage industry environment. According
18、 to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, L
19、ithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 16/11/2009 07:53, Uncontrolled Copy, (c) BSIBS EN 15692:2009EN 15692:2009 (E) 4 1 Scope This Euro
20、pean standard specifies a method for the direct determination of water in ethanol to be used in gasoline blends. It is applicable in the range 0,05 % (m/m) to 0,54 % (m/m). NOTE For the purposes of this European Standard, the term “% (m/m)” is used to represent the mass fraction. WARNING Use of this
21、 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 the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicabilit
22、y of regulatory limitations prior to use. 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 of the referenced document (including any amend
23、ments) applies. EN ISO 3170, Petroleum liquids Manual sampling (ISO 3170:2004) EN ISO 3696, Water for analytical laboratory use Specification and test methods (ISO 3696:1987) 3 Terms and definitions For the purposes of this European Standard, the following term and definition applies. 3.1 water cont
24、ent content of water determined by potentiometric Karl Fischer procedure as given in this document 4 Principle A weighed test portion is injected into the titration vessel of a potentiometric Karl Fischer apparatus. The water present is titrated to a potentiometric end point using Karl Fischer reage
25、nt. Iodine (I2), with presence of anhydride sulfur (SO2), of methanol (CH3OH) and of an appropriate nitrogen base (RN), is introduced for the Karl Fischer reaction. Based on the stoichiometry of the reaction, one mole of iodine reacts with one mole of water. The reaction can be expressed as follows:
26、 CH3OH + SO2 + RN RNHSO3CH3 H2O +I2 + RNHSO3CH3 + 2RN RNHSO4CH3+2RNHI 5 Reagents and materials Use only chemicals and reagents of recognized analytical grade. 5.1 Karl Fischer reagent, pyridine-free Karl Fischer reagent, containing iodine, sulfur dioxide and a odourless amine and with a nominal wate
27、r equivalent content of either 2 mg or 5 mg water per ml equivalent. The Karl Fisher reagent shall be standardized daily before use (see 8.1). Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 16/11/2009 07:53, Uncontrolled Copy, (c) BSIBS EN 15692:2009EN 15692:2009 (E) 5 5.2 Titration solvent
28、methanol, anhydrous methanol with a water content of less than 0,05 % (m/m). 5.3 Water, complying with grade 3 of EN ISO 3696. 6 Apparatus 6.1 Karl Fischer titrator, using a potentiometric end-point. NOTE Karl Fischer titrators are commercially available and some of them automatically stop the titra
29、tion at the end-point. Instructions for operation of these devices are provided by the manufacturer and are not described here. The method described in this document is using a titrator with a 5 ml burette. 6.2 Electrode platinum/platinum 6.3 Syringes NOTE Needles with bores between 0,5 mm and 0,8 m
30、m have been found suitable, such as syringe of single use with Luer connection, 5 ml or 10 ml capacity. 6.3.1 Syringe, of approximately 10 l capacity, fitted with a needle of sufficient length to enable the tip to reach under the surface of the liquid in the titration vessel when inserted through th
31、e inlet-port septum. 6.3.2 Syringe, of approximately 10 ml capacity, fitted with a needle of sufficient length to enable the tip to reach under the surface of the liquid in the titration vessel when inserted through the inlet-port septum. 6.4 Analytical balance, capable of weighing with an accuracy
32、of 0,1 mg. 6.5 Automatic burette, of 5 ml or 10 ml capacity, protected from humidity by the use of a molecular sieve (6.6) at the top. NOTE Although it is recommended that an automatic burette connected to a reservoir containing the Karl Fischer reagent is used, a burette, of approximately 5 ml capa
33、city, fitted with a guard tube filled with molecular sieve (6.6) to prevent the ingress of moisture, may also be used. 6.6 Molecular sieve, granulometry proximally 1,6 mm to 2,5 mm, pore size close to 1 nm. If required to be dried it shall be placed in an oven at proximally 140 C for about 8 hours,
34、then cooled in a dessicator to room temperature. 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 and sample handling. 7.3 Samples shall be shaken before used. 7.4 Samples shall be stor
35、ed capped at room temperature in a dry place to avoid modification of water content. 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 nee
36、dle. Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 16/11/2009 07:53, Uncontrolled Copy, (c) BSIBS EN 15692:2009EN 15692:2009 (E) 6 8 Procedure 8.1 Standardization of the Karl Fischer reagent 8.1.1 Add sufficient of the titration solvent (5.2) to the clean, dry titration vessel (6.1) to cove
37、r the electrodes. Seal all openings to the vessel, start the magnetic stirrer and adjust for smooth stirring action. Turn on the indication circuit and add KF reagent (5.1) from the burette until the end point is reached. Swirl the titration vessel to dry inside walls. Add more KF reagent if needed
38、until a steady end point is reached and maintained for at least 15 s. Repeat these swirling and titration steps until the vessels walls are dry. 8.1.2 Fill a 10 l syringe (6.3.1) with pure water, taking care to eliminate air bubbles. Wipe the needle with a tissue to remove any residual water from it
39、s surface. Using the balance (6.4) weigh the syringe and the water and record the mass in mg (W). 8.1.3 Insert the needle of the syringe into the titration vessel via the inlet port septum. Ensure that the tip of the needle is below the surface of the titration solvent. Add the contents of the syrin
40、ge to the titration solvent in the vessel which has been adjusted to its end point. Titrate the water with KF reagent until a steady end point is reached and maintained at least 15 s. After adding water, do not shake the vessel. 8.1.4 Record, to the nearest 0,01 ml, the volume of titrant needed to r
41、each the end point (T). Reweigh the empty syringe and record the mass in mg. 8.1.5 To check the conformance of the KF reagent, calculate the water equivalence of KF reagent, use the following equation: F = W / T (1) where, F is the water equivalence of the KF reagent, expressed in mg/ml; W is the ma
42、ss of water added in mg (see 8.1.2); T is the volume of titrant needed to reach the end point, expressed in ml (see 8.1.4). 8.1.6 Repeat the procedure specified in 8.1.1 to 8.1.5 to give a duplicate value. 8.1.7 If the variation between the two titrations is greater than 2 % relative, discard the co
43、ntents of the titration vessel. Introduce a further portion of appropriate titration solvent into the vessel and repeat the standardization procedure starting from 8.1.1. 8.1.8 If the titrations for two further portions of water still vary by more than 2 % relative, it is likely that either the Karl
44、 Fischer reagent and/or the titration solvent have aged. Replace these with fresh reagents and repeat the procedure starting from 8.1.1 8.1.9 Record the mean water equivalence value. 8.2 Analysis 8.2.1 Add fresh titration solvent (5.2) to the clean, dry titration vessel (6.1) and titrate the solvent
45、 to the end point conditions as described in 8.1.1. Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 16/11/2009 07:53, Uncontrolled Copy, (c) BSIBS EN 15692:2009EN 15692:2009 (E) 7 8.2.2 Dry the inside of a 10 ml syringe (6.3.2) by drawing the titration solvent up into the syringe and discharg
46、ing back into the titration vessel. If the vessel contents become wet, add KF reagent (5.1) until the end point is maintained for at least 15 s without further addition of titrant. Repeat this drying procedure until no further addition of KF reagent is necessary to maintain the end point state for a
47、t least 15 s (alternatively, oven-dried syringes, cooled in a dessicator may be used). 8.2.3 Immediately after mixing, use the dry syringe to withdraw at least three portions of the sample and discard as waste. 8.2.4 Immediately withdraw a 4 ml to 8 ml (depending on the water content) test portion o
48、f the sample, clean the needle with a paper tissue and weight the syringe and contents to the nearest 0,1 mg. Insert the syringe into the titration vessel via the inlet port septum, such that the needle is above the surface of the solvent, and discharge its contents. Withdraw the syringe, reseal the
49、 vessel, reweigh to the nearest 0,1 mg and record the mass m1of the sample test portion taken. 8.2.5 Titrate to the end point state, which shall be stable for at least 15 s. Do not shake the cell after addition of the sample. 8.2.6 Record, to the nearest 0,01 ml, the volume of titrant needed to reach the end point (V) and the water equivalence of KF reagent (m2). NOTE The solvent should be changed when the test portion content exceeds 2 g of sample per 15 ml of solvent or when 4 ml of titrant per 15 ml of solvent has been added to the titration ve
