SIST EN 16423:2013

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Flüssiggas - Bestimmung gelöstes Residuals - Gaschromatografisches Prüfverfahren mit benützung von flüssigem, on-column InjektionGaz de pétrole liquéfié - Détermination des résidus dissous - Méthode par chromatographie en phase gazeuse avec injection liquide sur colonneLiquefied petroleum gases - Determination of dissolved residue - Gas chromatographic method using liquid, on-column injection75.160.30Plinska gorivaGaseous fuelsICS:Ta slovenski standard je istoveten z:EN 16423:2013SIST EN 16423:2013en,de01-december-2013SIST EN 16423:2013SLOVENSKI
STANDARD



SIST EN 16423:2013



EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM
EN 16423
October 2013 ICS 75.160.20 English Version
Liquefied petroleum gases - Determination of dissolved residue -Gas chromatographic method using liquid, on-column injection Gaz de pétrole liquéfié - Détermination des résidus dissous - Méthode par chromatographie en phase gazeuse avec injection liquide on-column
Flüssiggas - Bestimmung gelöster Rückstände - Gaschromatographisches Prüfverfahren durch Direkteinspritzung von Flüssigkeit auf die Säule This European Standard was approved by CEN on 31 August 2013.
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 bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC 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 CEN member into its own language and notified to the CEN-CENELEC Management Centre has the same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom.
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B-1000 Brussels © 2013 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 16423:2013: ESIST EN 16423:2013



EN 16423:2013 (E) 2 Contents Page Foreword .3 Introduction .4 1 Scope .5 2 Normative references .5 3 Terms and definitions .5 4 Principle .5 5 Reagents and materials .5 6 Apparatus .6 7 Sampling . 10 8 Preparation of apparatus . 10 9 Test procedure . 11 9.1 Safety and hazards . 11 9.2 Summary of the method . 11 9.3 Calibration . 11 9.4 Procedure . 12 10 Calculations . 13 11 Quality control . 14 12 Expression of results . 14 13 Precision . 14 13.1 General . 14 13.2 Repeatability . 14 13.3 Reproducibility . 15 14 Test report . 15 Annex A (normative)
Density calculation of the LPG and correction of the result . 16 Annex B (informative)
Quality control monitoring . 19 Annex C (informative)
Analysis of benzene, toluene and hydrocarbons C7 through C10 . 20 Annex D (informative)
Analysis of di-iso-propanolamine . 22 Annex E (informative)
FID linearity check. 23 Bibliography . 24
SIST EN 16423:2013



EN 16423:2013 (E) 3 Foreword This document (EN 16423:2013) 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, either by publication of an identical text or by endorsement, at the latest by April 2014 and conflicting national standards shall be withdrawn at the latest by April 2014. 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 identifying any or all such patent rights. According to the CEN/CENELEC Internal Regulations, the national standards organisations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom.
SIST EN 16423:2013



EN 16423:2013 (E) 4 Introduction Control over the residue content as specified in EN 589 is of considerable importance in end-use applications of Liquefied Petroleum Gas (LPG). Dissolved residual matter, also known as evaporation residue, in LPG is contamination which can occur during production, transportation or storage.
This standard has been developed as a potential replacement of the commonly used methods, as this method of determination: − is quicker and much more sensitive than manual methods, such as ASTM D2158 [1] or EN 15471 [2], which are based on evaporation of (large) sample volumes followed by visual or gravimetric estimation of residue content; − provides enhanced sensitivity in measurements of heavier (evaporation) residues compared to EN 15470 [3], with a quantification limit of 10 mg/kg total residue; − gives both quantitative results and information about contaminant composition such as boiling point range and fingerprint, which can be very useful in tracing the source of a particular contaminant.
SIST EN 16423:2013



EN 16423:2013 (E) 5 1 Scope This European Standard specifies a method for the determination of the dissolved residual matter, also known as evaporation residue, in liquefied petroleum gases (LPG), by gas chromatography in the range of (10 to 600) mg/kg (ppm mass).
This test method quantifies soluble organic compounds (hydrocarbon materials), sometimes called ‘evaporation residue’, which can be present in liquefied petroleum gases and which are substantially less volatile than the LPG product, i.e. with a boiling point between 174 °C and 522 °C (C10 to C40). Higher boiling materials, or materials that adhere permanently to the chromatographic column, will not be detected.
WARNING — This standard does not purport to address all of the safety concerns, if any, 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 of regulatory limitations prior to use. 2 Normative references The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN 589, Automotive fuels — LPG — Requirements and test methods EN ISO 4257, Liquefied petroleum gases — Method of sampling (ISO 4257)
EN ISO 8973:1999, Liquefied petroleum gases — Calculation method for density and vapour pressure (ISO 8973:1997) ISO 1998-1, Petroleum industry — Terminology — Part 1: Raw materials and products 3 Terms and definitions For the purposes of this document, the terms and definitions given in EN 589, ISO 1998-1, and the following apply. 3.1
high pressure liquefied gas injector sample introduction device which injects liquefied gas samples under pressure and at room temperature directly onto the chromatographic column thereby maintaining the sample in liquid phase during the injection process 3.2 pressure station device that supplies high pressure inert gas to a suitable sample cylinder and therefore maintains sample in the liquid phase during the injection procedure 4 Principle A small quantity of LPG is directly transferred in liquid phase from the sample cylinder on to a GC column using a high pressure liquefied gas injector. The mixture is then analysed by capillary gas chromatography and the dissolved residue content is quantified by the external standard method. 5 Reagents and materials IMPORTANT — Standards that are prepared in pentane, normally liquid at room temperature, shall be stored under refrigeration and transferred to sample cylinders prior to use. Alternatively, they can be stored in air tight cylinders.
SIST EN 16423:2013



EN 16423:2013 (E) 6 5.1 Mineral oil in LPG calibration mixture.
One of the following mixtures shall be selected for calibration: 5.1.1 Mineral oil in LPG calibration mixture, certified calibration mixture with about 50 mg/kg mineral oil in LPG. 5.1.2 Mineral oil in pentane calibration mixture. Prepare a calibration standard of mineral oil in pentane. Record the exact weighed value to the nearest mg of mineral oil and calculate the concentration in mg/kg. The concentration of the mineral oil shall be close to the expected concentration of the contamination in the LPG sample. 5.1.3 Mineral oil or local hydrocarbon fraction, boiling point range approximately C10 to C40.
Alternatively, a well characterised local hydrocarbon fraction, within the range C10 to C40, can be used to provide quantitative and qualitative comparison to the contaminant in the sample. Care should be taken to ensure no significant fraction falls outside the C10 to C40 range. 5.2 Validation standard, mineral oil in pentane. Prepare a validation standard of mineral oil in pentane. Record the exact weighed value to the nearest mg of mineral oil and calculate the concentration in mg/kg. The concentration of the mineral oil shall be close to the expected concentration of the contamination in the LPG sample.
5.3 n-Alkane retention time standard, mixture containing at least C10 and C40 in a concentration of (nominally) 5 mg/l each, dissolved in pentane or heptane. 5.4 Solvent, GC grade pentane. 6 Apparatus NOTE Successfully used columns and conditions are given in Table 1. 6.1 Gas chromatograph, equipped with a Large Volume Cold on Column Injector (LVOCI), linear temperature programmable column oven, and a flame ionisation detector (FID), with data acquisition and processing system. For checking the linearity of the FID one may use Annex E. 6.2 Solvent vent, controlled to allow venting the major part of the matrix. 6.3 Retention gap, uncoated stainless steel capillary.
6.4 Retaining pre-column, a column with a polydimethylsiloxane stationary phase. 6.5 Analytical column, a column with a polydimethylsiloxane stationary phase. 6.6 Column coupler, coupling device suitable for leak free coupling of the retention gap to the retaining pre-column.
See Figure 1 for a schematic overview of the couplings inside the GC oven and the couplings to the solvent vent valve. SIST EN 16423:2013



EN 16423:2013 (E) 7 Table 1 — Typical column configuration Equipment part Typical operation conditions Oven program 35 °C for 3 min, 35 °C to 340 °C at 25 °C/min, 340 °C for 10 min Inlet program Type: cool on-column Temp: 55 °C for 3 min, 55 °C to 340 °C at 25 °C/min, 340 °C for 9 min Detector settings Air flow: 400 ml/min Hydrogen flow: 40 ml/min Make up gas flow: 20 ml/min Temperature: 350 °C Data rate: 20 Hz Column Retention gap: Sulfinert®1) stainless steel capillary with inner diameter 0,53 mm and length of 5 m Retaining pre-column: 3 m HP-1, 0,53 mm, 2,65 µm
Analytical column: HP-1, 30 m, 0,32 mm, 0,25 µm Pressure station Sample flow: 2 ml/min Nitrogen pressure: 2 500 kPa Nitrogen purge pressure: 500 kPa Liquefied gas injector Injection: 25 ms
1) Sulfinert ® is a stainless steel treatment system from Restek Co., 110 Benner Circle, Bellefonte, PA 16823, USA. This information is given for the convenience of users of this European Standard and does not constitute an endorsement by CEN of the product named. Equivalent products may be used if they can be shown to lead to the same results.
SIST EN 16423:2013



EN 16423:2013 (E) 8 6.7 Column splitter, suitable for leak-free coupling of the retaining pre-column to one side of the analytical column and the deactivated capillary on the other side.
See Figure 1 for a schematic overview of the couplings inside the GC oven and the couplings to the solvent vent valve.
Key A solvent vent valve B cool on-column inlet C detector D column splitter E retention gap F retaining pre-column G analytical column Figure 1 — Column overview SIST EN 16423:2013



EN 16423:2013 (E) 9 6.8 High pressure liquefied gas injector, a high pressure valve as in Figure 2, directly connected to a needle which is inserted in the injection port of the GC, after which the valve is triggered in order to introduce a representative aliquot into the GC system without sample discrimination.
Key A electrical attachment B solenoid on C valve spring D spray tip E pressurised fuel injection F injector casing G plunger Figure 2 — High pressure valve SIST EN 16423:2013



EN 16423:2013 (E) 10 6.9 Pressure station, ensuring a sample in liquid phase at a constant pressure, with a typical configuration as in Figure 3.
Key A sample cylinder B sample line in C injection device D cool on column inlet E gas chromatograph F sample line out G rotometer H vaporiser I waste systemFigure 3 — Typical configuration of the pressure station 7 Sampling Unless otherwise specified in the commodity specification, samples shall be taken as described in EN ISO 4257 and/or in accordance with the requirements of national regulations for the sampling of the product under test. 8 Preparation of apparatus CAUTION —Take all the necessary safety measures and, in particular, earth the equipment in order to eliminate the risks associated with static electricity. 8.1 Gas chromatograph: install and verify performance in accordance with the manufacturer’s instructions. Typical operating conditions are shown in Table 1. 8.2 Pressure station: install in accordance with the manufacturer’s instructions. Purge sample and check carefully for leaks. Connect the outlet to a waste system. 8.3 High pressure liquefied gas injector: install in accordance with the manufacturer’s instructions.
8.4 Column configuration: install the columns as shown in Figure 1, using low dead volume connections, and check for leaks. SIST EN 16423:2013



EN 16423:2013 (E) 11 9 Test procedure 9.1 Safety and hazards 9.1.1 There is a significant fire hazard from LPG, and since the boiling point of LPG can be as low as -41 °C, there is a risk of freezing “burns”. Take appropriate safety precautions to prevent ignition or fire, and wear suitable protective equipment to protect against skin contact with LPG. 9.1.2 An appropriate laboratory ventilation system shall be used. 9.1.3 An appropriate waste line shall be installed. The pressure station and injector shall be connected to this line. The waste line shall exit outside the building. An appropriate waste facility shall be available for liquid (pentane). 9.1.4 The pressure station, cylinder, injector and controller shall be grounded appropriately. 9.2 Summary of the method a) A sample cylinder of LPG is pressurised on the pressure station to 2 500 kPa using nitrogen or helium.
b) The injection system is flushed with LPG in liquid phase at room temperature. The end of the injection purge line is connected to a heated vaporiser which vaporises the LPG before transporting it to a waste disposal system. c) After flushing, the injection device is routed to the GC injector port and LPG (25 ms activation time equivalent to 30 µl) is introduced via a high pressure valve and needle which is inserted into the Cool On Column inlet.
d) The gas chromatograph is equipped with a solvent vent which routes most of the LPG light components out of the analytical system and leaves behind the components of interest.
e) The dissolved residue to be determined is retained on the pre-column. f) After venting, the light ends, the flow from the pre-column is switched to the analytical column and a temperature program is started. g) Dissolved residue contaminants are separated and identified based on differences in boiling point temperature. h) Total residue is quantified using area summation of component
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