1、BRITISH STANDARDBS EN 15470:2007Liquefied petroleum gases Determination of dissolved residues High temperature Gas chromatographic methodThe European Standard EN 15470:2007 has the status of a British StandardICS 75.160.30g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g
2、44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58BS EN 15470:2007This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 December 2007 BSI 2007ISBN 978 0 580 56657 8National
3、forewordThis British Standard is the UK implementation of EN 15470:2007.The UK participation in its preparation was entrusted to Technical Committee PTI/15, Natural gas and gas analysis.A list of organizations represented on this committee can be obtained on request to its secretary.This publication
4、 does 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. Amendments issued since publicationAmd. No. Date CommentsEUROPEAN STANDARDNORME EUROPENNEEUROPI
5、SCHE NORMEN 15470November 2007ICS 75.160.20English VersionLiquefied petroleum gases - Determination of dissolved residues- High temperature Gas chromatographic methodGaz de ptrole liqufi - Dtermination des rsidus dissous- Mthode par chromatographie en phase gazeuse, hautetempratureFlssiggase - Besti
6、mmung der gelsten Rckstnde -Hochtemperatur-Gaschromatographie-VerfahrenThis European Standard was approved by CEN on 7 October 2007.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 stand
7、ard without any alteration. Up-to-date lists 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 la
8、nguage made by translationunder the responsibility 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, Finlan
9、d,France, Germany, Greece, Hungary, Iceland, 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
10、FR NORMUNGManagement Centre: rue de Stassart, 36 B-1050 Brussels 2007 CEN All rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN 15470:2007: EEN 15470:2007 (E) 2 Contents Page Foreword3 1 Scope 4 2 Normative reference 4 3 Terms and definitions
11、.4 4 Principle4 5 Reagents.5 6 Apparatus .5 7 Test procedure.5 7.1 Safety 5 7.2 Summary of the method5 7.3 Sampling procedure 6 7.4 Evaporation procedure .6 7.5 Gas Chromatography analysis of the evaporation residue 7 8 Calculations8 9 Expression of results 8 10 Precision.9 10.1 General9 10.2 Repeat
12、ability, r .9 10.3 Reproducibility, R 9 Annex A (normative) Equipment for the sampling line and evaporation device 10 A.1 Sampling set.10 A.2 Venting lines.10 Annex B (informative) Commercial equipment suitable for the method .12 B.1 General12 B.2 Tube, stainless steel (type 304), ref 30203 12 B.3 N
13、eedle valve type SS-SS 212 B.4 Gas chromatograph Hewlett Packard 5890.12 B.5 Flasks A1036337 12 B.6 The GC column is a weakly polar capillary column, high temperature, type HT5, supplied by SGE 12 Annex C (informative) Examples of gas chromatograms13 Bibliography 15 EN 15470:2007 (E) 3 Foreword This
14、 document (EN 15470:2007) has been prepared by Technical 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, ei
15、ther by publication of an identical text or by endorsement, at the latest by May 2008, and conflicting national standards shall be withdrawn at the latest by May 2008. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN and/or CEN
16、ELEC shall not be held responsible for identifying any or all such patent rights. According 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, Denm
17、ark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. EN 15470:2007 (E) 4 1 Scope This European Standard specifies
18、a method for determining the dissolved residual matter in liquefied petroleum gases (LPG), in the range of 40 mg/kg to 100 mg/kg. Higher concentrations can be determined by adjusting the sample size. The dissolved residue is the amount of organic compounds that are detectable by gas chromatography a
19、fter evaporation of the sample at ambient temperature and then in an oven at 105 C. This method is not suitable for detecting solid materials or for possibly high molecular weight polymers ( 1 000 g/mol). The advantages of this method are that a small quantity of LPG (50 g to 75 g) is required and t
20、he qualitative data available may indicate the origin of the residues (gas-oil, lubricants, plasticizers, etc.). This method has been developed as a potential replacement of the commonly used method described in EN ISO 13757 1, but is safer and more environmentally friendly. In addition, this new me
21、thod is more accurate. The precision data of the method have been determined from 20 mg/kg to 100 mg/kg. For a higher content of residue, the precision has not been tested, but remains of lesser interest as typical specifications are in the range of 20 mg/kg to 100 mg/kg. NOTE An alternative Europea
22、n Standard, EN 15471 2, specifies a gravimetric method, which has the same scope and slightly worst fidelity data. WARNING Use of this method involves hazardous materials and operations. It is the responsibility of the user to establish appropriate safety and health precautions. All handling must be
23、 performed in a fume hood. 2 Normative reference 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 amendments) applies.
24、EN ISO 4257, Liquefied petroleum gases - Method of sampling (ISO 4257:2001) 3 Terms and definitions For the purposes of this document, the following term and definition applies. 3.1 liquefied petroleum gas (LPG) petroleum gas that can be stored and/or handled in the liquid phase under moderate condi
25、tions of pressure and at ambient temperature, consisting predominantly of propane, butanes, with small proportions of propene, butenes and pentanes/pentenes 4 Principle A known mass of LPG, between 50 g and 75 g, is sampled and evaporated in a standard small glass flask. The residue is heated in an
26、oven at 105 C for 1 h. It is then diluted with a solvent and one internal standard is added. The mixture is then analyzed by a capillary gas chromatography and quantified by the internal standard method. EN 15470:2007 (E) 5 5 Reagents 5.1 Isopropylalcohol (IPA), analytical grade. 5.2 Carbon dioxide,
27、 solid for cooling. 5.3 Carbon disulfide, analytical grade (99,9 % minimum). 5.4 Normal Octane, analytical grade (99,9 % minimum). 5.5 Pentane, analytical grade (99,5 % minimum). 6 Apparatus 6.1 Sample cylinder, of a total mass compatible with the balance used; preferably made of stainless steel fit
28、ted with two stainless steel valves free of oily materials, conforming to EN ISO 4257. 6.2 Cooling bath, comprised of a (0,5 to 2) dl Dewar flask, filled with an appropriate liquid, e.g. IPA cooled with solid carbon dioxide, to achieve a temperature of about 60 C. 6.3 Sampling set, according to Anne
29、x A. 6.4 Balance for weighting, maximum weight depending of the sample cylinder weight (for instance 16 kg or 30 kg), with an accuracy of 1 g or better. 6.5 Analytical balance, suitable, accurate to within 0,1 mg or better. 6.6 Vent line, according to Annex A. 6.7 Glass flasks, (100 ml to 150 ml) wi
30、th screw open caps (for example as in B.5 or other). 6.8 Septum, adapted to the flask, PTFE/silicon (for example as in B.5 or other). 6.9 Laboratory gloves, of fine PVC, talc free. 6.10 Gas chromatograph, with its integrator and its automatic injector (see B.4 for an example). 6.11 Capillary column,
31、 (see B.6 for an example). 7 Test procedure 7.1 Safety CAUTION It is essential to work under an explosion-proof hood. In order to remove both the LPG and carbon disulfide vapours take all the necessary safety measures and, in particular, earth the equipment in order to eliminate the risks associated
32、 with static electricity. 7.2 Summary of the method A small quantity of LPG (typically around 75 g) is transferred in liquid phase from the sample cylinder to a closed glass flask cooled in an IPA / CO2ice mixture. The transfer line shall not be cooled to reduce the possibility that a frozen substan
33、ce is retained. The dual-phase mixture will condense when transferred in the cooled flask. The sampling flow is controlled by the needle valve inserted in the sampling line. The sample weight is determined by weighing the sample cylinder. EN 15470:2007 (E) 6 After transfer, the LPG is left to evapor
34、ate at ambient temperature. The glass container is then opened and placed for 1 h in an oven at 105 C. The resulting residue is dissolved in CS2and analyzed by gas chromatography using an internal standard. 7.3 Sampling procedure a) Put the sample cylinder (6.1) on the balance (6.4); b) Assemble the
35、 apparatus, using the set shown in Annex A and following Figure A.1, by connecting the liquid phase valve of the sample cylinder to the sampling line comprising: PTFE line; spindle-needle valve; 1/16” stainless steel injection tubing. c) Fix the PTFE line to a support in order that the sampling oper
36、ations do not disturb the balance; d) Prepare a cooling bath (6.2) by filling a beaker or small Dewar with solid carbon dioxide and IPA; e) Clean a glass flask (6.7) with analytical pentane; f) Prepare a cap and a septum (6.8) with two small holes permitting two passages for 1/16 inch tubings; g) Pl
37、ace a clean glass flask (with its cap, its pierced PTFE septum and its venting line in position) in the cooling bath for at least 1 min before starting the sampling; NOTE This enables a better introduction of the sample into the glass container. h) Close the needle valve; i) Open the sample cylinder
38、 cautiously and fill/purge the sampling line by opening the needle valve slightly and progressively; j) Close the needle valve when the LPG flows regularly; k) Introduce the injection end in the flask; l) Record the weight of the sample cylinder, m1; m) Sample slowly the LPG by opening the needle va
39、lve; n) When about 100 ml has been sampled, close the needle valve; o) Record the weight of the sample cylinder, m2; p) The weight m of the LPG sample in grams is given by the calculation: 12 mmm = (1) q) Repeat the procedure for the required number of samples. 7.4 Evaporation procedure Disconnect t
40、he sampling line and leave the vaporized gas to exit through the venting line. NOTE The lower end of the venting line should not be placed in the boiling liquid phase. EN 15470:2007 (E) 7 The evaporation of the sample starts as soon as the sampling begins; the flask is left at ambient temperature or
41、 gently warmed by any appropriate device to a temperature not exceeding 25 C. The gas is vented through the hood. When the natural evaporation is completed, the flask is left for the duration of 1 h at 105 C, with the cap opened. The flask is then cooled down for 30 min in a desiccator and closed wi
42、th its cap and septum. The test flask now contains the dissolved evaporation residue, the amount of which will be determined by gas chromatography in the second phase of the analysis. CAUTION Close the flask with the septum with the PTFE side downwards. Store the flask in the upright position. 7.5 G
43、as chromatography analysis of the evaporation residue 7.5.1 Summary of the method The evaporation residue obtained in 7.4 is diluted and washed with a solution of CS2 (solution A) containing an internal standard (octane). The solution is then injected onto the GC capillary column. The residue amount
44、 is determined by the internal standard method. The result should be corrected by a blank determination. 7.5.2 Preparation of the solution A The solution A contains about 40 mg of octane weighted at 0,1 mg diluted in 100 g of CS2. 7.5.3 Operating conditions A recommended scheme of operating conditio
45、ns is reported in Table 1: Table 1 Carrier gas nature helium flow 4 ml/min Injector type splitless temperature 380 C Injection type automatic volume 2 l Detector type FID temperature 400 C hydrogen flow 30 ml/min air flow 350 ml/min make-up gas flow 30 ml/min Signal mode compensation Oven initial te
46、mperature 10 C during 1 min final temperatur 400 C rate 15 C/min EN 15470:2007 (E) 8 7.5.4 Determination of the blank First make a sufficient number of runs to purge the GC system. Inject 2 l of solution A onto the analytical column. Integer the portion of chromatogram eluted between N-C8 and the en
47、d of the analysis (see for an example Figure C.1). The value of the area Sbcalculated in this way shall not be more than 2 % of the area of the N-C8 peak. It will be subtracted from the area of test samples. 7.5.5 Sample analysis Weigh the closed flask to the nearest 10 mg. Introduce into the closed
48、 test glass flask containing the evaporation residue about 4 ml, weighed to the nearest 10 mg, of the solution A. Carefully and slowly wash the walls of the flask with the mixture. The resulting solution (X) in the closed flask is then used for GC injection. If the GC analysis cannot be carried out
49、immediately after evaporation in the oven, store the glass containers in the dark in a desiccator. Dilute the residue with solution A just before making the GC analysis. Inject the solution X into the column using the same analytical conditions as for the blank determination. The area (Sx) of the chromatogram is integrated between the N-C8 and the end of the analysis in the same conditions as for the blank determination (see Figure C.2). 8 Calculations The amount of evaporation residues (ER), expressed in mg/kg is given by the followi
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