SIST EN 14112:2003

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.ORþHYDQMHErzeugnisse aus pflanzlichen und tierischen Fetten und Ölen - Fettsäure-Methylester (FAME) - Bestimmung der Oxidationsstabilität (beschleunigter Oxidationstest)Produits dérivés des corps gras - Esters méthyliques d'acides gras (EMAG) - Détermination de la stabilité a l'oxydation (Essai d'oxydation accélérée)Fat and oil derivatives - Fatty Acid Methyl Esters (FAME) - Determination of oxidation stability (accelerated oxidation test)67.200.10Animal and vegetable fats and oilsICS:Ta slovenski standard je istoveten z:EN 14112:2003SIST EN 14112:2003en01-november-2003SIST EN 14112:2003SLOVENSKI
STANDARD



SIST EN 14112:2003



EUROPEAN STANDARDNORME EUROPÉENNEEUROPÄISCHE NORMEN 14112April 2003ICS 67.200.10English versionFat and oil derivatives - Fatty Acid Methyl Esters (FAME) -Determination of oxidation stability (accelerated oxidation test)Produits dérivés des corps gras - Esters méthyliquesd'acides gras (EMAG) - Détermination de la stabilité àl'oxydation (essai d'oxydation accélérée)Erzeugnisse aus pflanzlichen und tierischen Fetten un Ölen- Fettsäure-Methylester (FAME) - Bestimmung derOxidationsbeständigkeit (Beschleunigte Oxydationsprüfung)This European Standard was approved by CEN on 2 January 2003.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 such nationalstandards may be obtained on application to the 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 Management Centre has the same status as the officialversions.CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece,Hungary, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Slovakia, Spain, Sweden, Switzerland and UnitedKingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMITÉ EUROPÉEN DE NORMALISATIONEUROPÄISCHES KOMITEE FÜR NORMUNGManagement Centre: rue de Stassart, 36
B-1050 Brussels© 2003 CENAll rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN 14112:2003 ESIST EN 14112:2003



EN 14112:2003 (E)2ForewordThis document (EN 14112:2002) has been prepared by Technical Committee CEN/TC 307, "Oilseeds, vegetableand animal fats and oils and their by-products - Methods of sampling and analysis", the secretariat of which is heldby AFNOR.This European Standard shall be given the status of a national standard, either by publication of an identical text orby endorsement, at the latest by October 2003, and conflicting national standards shall be withdrawn at the latestby October 2003.This document has been prepared under Mandate M/245 on Fatty Acid Methylester (FAME) given to CEN by theEuropean Commission and the European Free Trade Association.Annexes A and B are informative.According to the CEN/CENELEC Internal Regulations, the national standards organizations of the followingcountries are bound to implement this European Standard: Austria, Belgium, Czech Republic, Denmark, Finland,France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal,Slovakia, Spain, Sweden, Switzerland and the United Kingdom.SIST EN 14112:2003



EN 14112:2003 (E)3IntroductionThis European Standard is based on the ISO 6886 [1], which was specifically adapted for the determination ofoxidation stability of fatty acid methyl esters (FAME).SIST EN 14112:2003



EN 14112:2003 (E)41 ScopeThis European Standard specifies a method for the determination of the oxidation stability of fatty acid methylesters (FAME) at 110 °C.2 Terms and definitionsFor the purposes of this European Standard, the following terms and definitions apply.2.1induction periodtime which passes between the moment when the measurement is started and the moment when the formation ofoxidation products rapidly begins to increase2.2oxidation stabilityinduction period determined according to the procedure specified in this European Standard. Oxidation stability isexpressed in hours3 PrincipleA stream of purified air is passed through the sample which has been brought to a specified temperature. Thevapours released during the oxidation process, together with the air, are passed into a flask containing water whichhas been demineralized or distilled and contains an electrode for measuring the conductivity. The electrode isconnected to a measuring and recording device. It indicates the end of the induction period when the conductivitybegins to increase rapidly. This accelerated increase is caused by the dissociation of volatile carboxylic acidsproduced during the oxidation process and absorbed in the water.4 Reagents and materialsUse only reagents of recognised analytical grade, and distilled or demineralized water.4.1Molecular sieve, with moisture indicator, pore size 0,3 mm. The molecular sieve should be dried in an ovenset at 150 °C and cooled down to room temperature in a desiccator.4.2Acetone.4.3Alkaline laboratory glass cleaning solution.4.4Glycerol.5 ApparatusUsual laboratory equipment and, in particular, the following.5.1Appliance for the determination of oxidation stabilitySee Figures 1 and 2 for diagrammatic representations.NOTEAn appliance for determining oxidation stability can be obtained commercially under the trade name Rancimat,model 743, from Methrom AG, Herisau, Switzerland1).
1)Rancimat, model 743, is an example of suitable equipment available commercially. This information is given for the convenience of users ofthis European Standard and does not constitute an endorsement by CEN of this equipment.SIST EN 14112:2003



EN 14112:2003 (E)55.1.1Air filter, comprising a tube fitted with filter paper at the ends and filled with a molecular sieve (4.1),connected to the suction end of a pump.5.1.2Gas diaphragm pump, with an adjustable flow rate of 10 l/h in combination with an apparatus to controlthe flow rate manually or automatically with a maximum deviation of ± 1,0 l/h from the set value.5.1.3Reaction vessels of borosilicate glass, connected to a sealing cap.The sealing cap shall be fitted with a gas inlet and outlet tube. The cylindrical part of the vessel shall preferably benarrower a few centimetres below the top in order to break any emerging foam. An artificial foam blocker (e.g. glassring) may also be used for this purpose.5.1.4Closed measurement cells, of approximately 150 ml capacity, with a gas inlet tube extending to thebottom inside of the vessel. The cell shall be provided at the top with ventilation holes.5.1.5Electrodes, for measuring conductivity with a measuring range of 0 µS/cm to 300 µS/cm aligned with thedimensions of the measurement cell (5.1.4).5.1.6Measuring and recording apparatus, comprising:a) an amplifier ;b) a recorder for registering the measuring signal of each of the electrodes (5.1.5).5.1.7Thyristor and contact thermometer graduated in 0,1 °C or Pt 100 element to measure the blocktemperature, with attachments for relay connection and an adjustable heating element; temperature scale 0 °C to150 °C.5.1.8Heating block, made of cast aluminium, adjustable to a temperature up to (150 ± 0,1) °C. The block shallbe provided with holes for the reaction vessels (5.1.3), and an aperture for the contact thermometer (5.1.7).Alternatively, a heating bath may be used, filled with oil suitable for temperatures up to 150 °C and adjustable tothe nearest 0,1 °C.5.2Certified and calibrated Thermometer or Pt100 element, with a temperature range up to 150 °C,graduated in 0,1 °C.5.3Measuring pipettes (two), of capacity 50 ml and 5 ml.5.4Oven, capable of being maintained up to (150 ± 3) °C.5.5Connecting hoses, flexible and made of inert material [polytetrafluoroethylene (PTFE) or silicone].SIST EN 14112:2003



EN 14112:2003 (E)6Key1Air filter (5.1.1)2Gas diaphragm pump with flow rate control (5.1.2)3Reaction vessel (5.1.3)4Measurement cell (5.1.4)5Electrode (5.1.5)6Measuring and recording apparatus (5.1.6)7Thyristor and contact thermometer (5.1.7)8Heating block (5.1.8)Figure 1 — Diagrammatic representation of the apparatusSIST EN 14112:2003



EN 14112:2003 (E)7Key1Measuring vessel2Electrode3Measuring solution4Reaction vessel5Sample6Heating block7AirFigure 2 — Diagrammatic representation of heating block, reaction vessel and measurement cell6 SamplingIt is important that the laboratory receive a sample which is truly representative and has not been damaged orchanged during transport and storage.Sampling is not part of the method specified in this European Standard. A recommended sampling method is givenin EN ISO 5555 [2]Store the sample in the dark at about 4 °C.7 Preparation of measurement7.1 Preparation of test sampleIn order to prevent the preparation of the test sample from influencing the test result, all handling of the laboratorysample shall be restricted to the steps given below.Remove the required quantity from the centre of the carefully homogenised sample using a pipette.NOTESamples should be analysed immediately after the test sample preparation.SIST EN 14112:2003



EN 14112:2003 (E)87.2 Preparation of apparatus7.2.1 Cleaning procedureWash the reaction vessels, measurement cells and their inlet and outlet tubes at least three times with acetone inorder to remove as much of the organic residue as possible. Rinse with tap water.Fill the vessels completely with an aqueous alkaline laboratory glass cleaning solution and mount the inlet tubes.Store the vessels at least 2 h at 70 °C.Rinse the purified vessels and their inlet and outlet tubes thoroughly with tap water and finally with demineralized ordistilled water. Dry them in an oven for at least 1 h at 110 °C.NOTE 1If there are disposable reaction vessels available, the described cleaning procedure for these is not necessary.NOTE 2Check of the cleanliness of vessels: run clean vessels using distilled water for six hours in the same experimentalconditions in order to check if the measured conductivity shows any significant change during time. Vessels showingconductivity changes should be discarded and cleaned again. The vessels passing the test can be used after water removal anddrying in oven.7.2.2 Determination of temperature correctionThe difference between the actual temperature of the sample and the temperature of the heating block is calledtemperature correction DT. For the determination of D T an external calibrated temperature sensor is used.Before starting the determination of DT the heating block has to be switched on and the target temperature has tobe rea
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