1、BRITISH STANDARDBS 2000-428:2004BS EN 237:2004Methods of test for petroleum and its products BS 2000-428: Liquid petroleum products Petrol Determination of low lead concentrations by atomic absorption spectrometry The European Standard EN 237:2004 has the status of a British StandardICS 75.160.20g49
2、g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58(Identical with IP 428:2004)Licensed Copy: Wang Bin, na, Tue Feb 14 02:50:51 GMT 2006, Uncontrolled Cop
3、y, (c) BSIBS 2000-428:2004This British Standard was published under the authority of the Standards Policy and Strategy Committee ISBN 0 580 46111 4National forewordThis British Standard is the official English language version of EN 237:2004. It supersedes BS EN 237:1996, BS 2000-428:1996 which is w
4、ithdrawn.The UK participation in its preparation was entrusted to Technical Committee PTI/13, Petroleum testing and terminology, which has the responsibility to: aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or
5、proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK.A list of organizations represented on this committee can be obtained on Cross-referencesThe British Standards which implement international or European pub
6、lications referred to in this document may be found in the BSI Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Search” facility of the BSI Electronic Catalogue or of British Standards Online.This publication does not purport to include all the ne
7、cessary provisions of a contract. Users are responsible for its correct application.Compliance with a British Standard does not of itself confer immunity from legal obligations.Summary of pagesThis document comprises a front cover, an inside front cover, the EN title page, pages 2 to 11 and a back c
8、over.The BSI copyright notice displayed in this document indicates when the document was last issued.Amendments issued since publicationAmd. No. Date CommentsEnergy Institute, under the brand of IP publishes and sells all parts of BS 2000, and all BS EN petroleum test methods that would be part of B
9、S 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 W1G 7AR. on 14 November 2005 BSI 14 November 2
10、005Tel: 020 7467 7100. Fax: 020 7255 1472.Licensed Copy: Wang Bin, na, Tue Feb 14 02:50:51 GMT 2006, Uncontrolled Copy, (c) BSIEUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN 237September 2004ICS 75.160.20 Supersedes EN 237:1996English versionLiquid petroleum products - Petrol - Determination of l
11、ow leadconcentrations by atomic absorption spectrometryProduits ptroliers liquides - Essence - Dtermination desbasses teneurs en plomb par spectromtrie dabsorptionatomiqueFlssige Minerallerzeugnisse - Ottokraftstoff -Bestimmung von niedrigen Bleigehalten durchAtomabsorptionspektrometrieThis European
12、 Standard was approved by CEN on 9 July 2004.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 lists and bibliographical references concerning
13、such nationalstandards may be obtained on application to the Central Secretariat 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
14、and notified to the Central Secretariat has the same status as the officialversions.CEN 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, Ne
15、therlands, Norway, Poland, Portugal, 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 2004 CEN All rights of exploitation in any fo
16、rm and by any means reservedworldwide for CEN national Members.Ref. No. EN 237:2004: ELicensed Copy: Wang Bin, na, Tue Feb 14 02:50:51 GMT 2006, Uncontrolled Copy, (c) BSIEN 237:2004 (E) 2ContentspageForeword31 Scope 42 Normative references 43 Principle44 Reagents and materials 55 Apparatus .66 Samp
17、ling.67 Procedure .67.1 General preparation.67.2 Preparation of calibration solutions (0,25 mg/l, 0,50 mg/l, 0,75 mg/l, and 1,0 mg/l of lead) 67.3 Preparation of the test solution77.4 Preparation of instrument.77.5 Determination.78 Calculation79 Expression of results 810 Precision.810.1 General back
18、ground810.2 Repeatability, r .810.3 Reproducibility, R 811 Test report 8Annex A (informative) Alternative procedure 9Licensed Copy: Wang Bin, na, Tue Feb 14 02:50:51 GMT 2006, Uncontrolled Copy, (c) BSIEN 237:2004 (E) 3Foreword This document (EN 237:2004) has been prepared by Technical Committee CEN
19、/TC 19 “Petroleum products, lubricants and related products”, 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 March 2005, and conflicting national standard
20、s shall be withdrawn at the latest by March 2004. This document supersedes EN 237:1996. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Cyprus, Czech Republic, Denmark,
21、 Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. Licensed Copy: Wang Bin, na, Tue Feb 14 02:50:51 GMT 2006, Uncontrolled Copy,
22、(c) BSIEN 237:2004 (E) 41 Scope This document specifies an atomic absorption spectrometric test method for the determination of the lead content of petrol in the range 2,5 mg/l to 10,0 mg/l. This test method is independent of the lead alkyl type. NOTE 1 Annex A describes an alternative procedure but
23、 with a poorer precision for the determination of the lead content of petrol in the range 3,0 mg/l to 10,0 mg/l. This procedure is also independent of the lead alkyl type. NOTE 2 For the purposes of this document, the term “% (V/V)” is used to represent the volume fraction. WARNING The use of this d
24、ocument 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 applicability
25、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 amendme
26、nts) applies. EN ISO 1042, Laboratory glassware One-mark volumetric flasks (ISO 1042:1998).EN ISO 3170, Petroleum liquids - Manual sampling (ISO 3170:2004).EN ISO 3171, Petroleum liquids - Automatic pipeline sampling (ISO 3171:1988).ISO 385-1, Laboratory glassware - Burettes - Part 1: General requir
27、ements.ISO 648, Laboratory glassware One-mark pipettes.3 Principle The sample, diluted to the tenth (V/V) with methyl isobutyl ketone and treated with iodine, is aspirated into the air/acetylene flame of an atomic absorption spectrometer. The absorbance is measured at a wavelength of 217,0 nm and is
28、 compared with that of calibration solutions of known lead concentrations. NOTE Annex A describes an alternative procedure, but with a poorer precision, that may be used when the spectrometer is not stable enough in the wavelength region of 217,0 nm to obtain correct results according to the above.
29、Licensed Copy: Wang Bin, na, Tue Feb 14 02:50:51 GMT 2006, Uncontrolled Copy, (c) BSIEN 237:2004 (E) 54 Reagents and materials Use only reagents of recognised analytical grade. 4.1 Air, oil free, under pressure in a steel cylinder, or compressed air. 4.2 Acetylene, under pressure in a steel cylinder
30、. WARNING Compressed gases shall be stored outside the laboratory. 4.3 Toluene 4.4 2,2,4-Trimethylpentane (iso-octane) 4.5 Methyl isobutyl ketone (MIBK) 4.6 50 %/50 % (V/V) mixture of toluene and iso-octane4.7 Aliquat 336 (tricapryl methyl ammonium chloride)4.8 10 % (V/V) Aliquat 336/MIBK SolutionDi
31、ssolve 100 ml (88,0 g 0,1 g) of Aliquat 336 with MIBK and make up to 1 l. 4.9 1 % (V/V) Aliquat 336/MIBK SolutionDissolve 10 ml (8,80 g 0,05 g) of Aliquat 336 with MIBK and make up to 1 l. 4.10 Iodine solution.Dissolve 3,0 g 0,1 g of iodine crystals with toluene and make up to 100 ml. 4.11 Lead chlo
32、ride (PbCl2), of 99 % mass purity grade. 4.12 Concentrated lead standard stock solution, c(Pb) = 1 000 mg/l. Dissolve 335,6 mg of lead chloride (4.11) previously dried at about 105 C for at least 3 h in about 200 ml of 10 % Aliquat 336/MIBK solution (4.8) in a 250 ml volumetric flask (5.4). Dilute t
33、o the mark with the 10 % Aliquat solution, mix, and store in a brown bottle having a polyethylene-lined cap. This solution contains 1 000 mg/l of lead. NOTE 1 The concentrated lead standard stock solution is stable for at least 6 months. NOTE 2 Smaller volumes may be prepared, e.g. 100 ml, however t
34、he precision statement as given in clause 10 has been established using 250 ml volumetric flasks. 4.13 Diluted lead standard stock solution, c(Pb) = 100 mg/l. Using a pipette (5.5), transfer accurately 25,0 ml of the concentrated lead standard stock solution (4.12) into a 250 ml volumetric flask (5.
35、4), and dilute to the mark with the 1 % Aliquat 336/MIBK solution (4.9). Store in a brown bottle having a polyethylene-lined cap. This solution contains 100 mg/l of lead. NOTE Smaller volumes may be prepared, e.g. 100 ml, however the precision statement as given in clause 10 has been established usi
36、ng 250 ml volumetric flasks. 4.14 Lead standard solutions, 2,5 mg/l, 5,0 mg/l, 7,5 mg/l and 10,0 mg/l of leadUsing a pipette (5.5) or a micro-burette (5.3), transfer accurately 2,5 ml, 5,0 ml, 7,5 ml and 10,0 ml of the diluted lead standard stock solution (4.13) to 100 ml volumetric flasks; add 5 ml
37、 of 1 % Aliquat 336/MIBK solution (4.9) to each flask; dilute to the mark with MIBK (4.5). Mix thoroughly and store in bottles having polyethylene-lined caps. Licensed Copy: Wang Bin, na, Tue Feb 14 02:50:51 GMT 2006, Uncontrolled Copy, (c) BSIEN 237:2004 (E) 65 Apparatus Usual laboratory apparatus
38、and glassware, together with the following: 5.1 Flame atomic absorption spectrometer, suitable for measurements at a wavelength of 217,0 nm, and fitted with a burner feed with acetylene and air, suitable for use with organic solutions. NOTE The attention of the user is drawn that the alternative pro
39、cedure as described in Annex A requires the use of a flame absorption spectrometer that is suitable for measurements at a wavelength of 283,3 nm. 5.2 Lead hollow-cathode lamp.5.3 Micro-burette, capacity 10 ml, conforming to class A of ISO 385-1. 5.4 One-mark volumetric flasks, capacity 50 ml, 100 ml
40、, 250 ml and 1 l conforming to class A of EN ISO 1042. 5.5 One-mark pipettes, capacity 2 ml, 5 ml, 10 ml, 20 ml, 25 ml and 50 ml, conforming to class A of ISO 648, with suction ball. 5.6 Micropipette, 100 l Eppendorf type or equivalent. 5.7 Analytical balance, capable of weighing to the nearest 0,1
41、mg. 6 Sampling Unless otherwise specified in the commodity specification, samples shall be taken as described in EN ISO 3170 or EN ISO 3171, and/or in accordance with the requirements of national standards or regulations for the sampling of petrol. 7 Procedure 7.1 General preparation Note and record
42、 the temperature, Tx, at which all volumetric measurements are made. The volumetric glassware is usually calibrated at 20 C. Prepare the calibration solutions and the test solution on the same day and measure on that day. 7.2 Preparation of calibration solutions (0,25 mg/l, 0,50 mg/l, 0,75 mg/l, and
43、 1,0 mg/l of lead)7.2.1 To a 50 ml volumetric flask containing 30 ml of MIBK (4.5), add 5,0 ml of low lead standard solution (4.14) and 5,0 ml of the toluene/iso-octane mixture (4.6). Repeat this operation for each of the low lead standard solutions (2,5 mg/l, 5,0 mg/l, 7,5 mg/l, and 10,0 mg/l of le
44、ad). In the case of blank, add only 5,0 ml of the toluene/iso-octane mixture. 7.2.2 Add immediately 0,1 ml of the iodine solution (4.10) by means of a micropipette (5.6). Mix thoroughly and allow to react for at least 1 min. 7.2.3 Add 5 ml of the 1 % Aliquat 336/MIBK solution (4.9) and mix thoroughl
45、y. 7.2.4 Dilute to volume with MIBK (4.5) and mix thoroughly. Licensed Copy: Wang Bin, na, Tue Feb 14 02:50:51 GMT 2006, Uncontrolled Copy, (c) BSIEN 237:2004 (E) 77.3 Preparation of the test solution 7.3.1 Transfer approximately 30 ml of MIBK (4.5) into a 50 ml volumetric flask (5.4), add 5,0 ml of
46、 the sample by means of a pipette (5.5) and mix. 7.3.2 Add immediately 0,1 ml of the iodine solution (4.10) by means of a micropipette (5.6). Mix thoroughly and allow to react for at least 1 min. 7.3.3 Add 5 ml of 1 % Aliquat 336 Solution (4.9) and mix thoroughly. 7.3.4 Dilute to volume with MIBK (4
47、.5) and mix thoroughly. 7.4 Preparation of instrument 7.4.1 Install the lead hollow-cathode lamp (5.2) in the spectrometer (5.1) and leave the apparatus switched on for the time necessary to achieve stability. 7.4.2 Adjust the lamp current, the attenuation and the slit, to suit the characteristics o
48、f the apparatus. Adjust the wavelength to the region of 217,0 nm in order to obtain the maximum intensity. 7.4.3 Install the burner-head for acetylene-air and ignite the flame. 7.4.4 Using pure MIBK, adjust the flow rates of acetylene (4.2) and air (4.1) and the sample aspiration to obtain an oxidis
49、ing flame, which is fuel lean and light blue in colour. 7.4.5 Aspirate pure MIBK (4.5) to set the zero of the instrument. 7.4.6 Aspirate the 1,0 mg/l calibration solution and adjust the burner position to get a maximum response. 7.4.7 Aspirate pure MIBK (4.5) to set the zero of the instrument and check the blank and the four calibration solutions (7.2) for linearity. 7.5 Determination Aspirate the calibration solutions (7.2) and the test solution (7.3) and record the absorbance values. NOTE The stability of the instrument should be checked by analysing
