SIST EN 14112:2016

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 (Beschleunigte Oxidationsprüfung)Produits dérivés des corps gras - Esters méthyliques d'acides gras (EMAG) - Détermination de la stabilité à l'oxydation (essai d'oxydation accéléré)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 14112:2016SIST EN 14112:2016en01-november-2016SIST EN 14112:2016SLOVENSKI
STANDARDSIST EN 14112:20031DGRPHãþD



SIST EN 14112:2016



EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM
EN 14112
September
t r s x ICS
x yä t r rä s r Supersedes EN
s v s s tã t r r uEnglish Version
Produits dérivés des corps gras æ Esters méthyliques
Erzeugnisse aus pflanzlichen und tierischen Fetten und This European Standard was approved by CEN on
z July
t r s xä
egulations which stipulate the conditions for giving this European Standard the status of a national standard without any alterationä Upætoædate lists and bibliographical references concerning such national standards may be obtained on application to the CENæCENELEC Management Centre or to any CEN memberä
translation under the responsibility of a CEN member into its own language and notified to the CENæCENELEC Management Centre has the same status as the official versionsä
CEN members are the national standards bodies of Austriaá Belgiumá Bulgariaá Croatiaá Cyprusá Czech Republicá Denmarká Estoniaá Finlandá Former Yugoslav Republic of Macedoniaá Franceá Germanyá Greeceá Hungaryá Icelandá Irelandá Italyá Latviaá Lithuaniaá Luxembourgá Maltaá Netherlandsá Norwayá Polandá Portugalá Romaniaá Slovakiaá Sloveniaá Spainá Swedená Switzerlandá Turkey and United Kingdomä
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CEN-CENELEC Management Centre:
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9
t r s x CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Membersä Refä Noä EN
s v s s tã t r s x ESIST EN 14112:2016



EN 14112:2016 (E) 2 Contents Page European foreword . 3 Introduction . 4 1 Scope . 5 2 Normative references . 5 3 Terms and definitions . 5 4 Principle . 5 5 Reagents and materials . 6 6 Apparatus . 6 7 Sampling . 8 8 Preparation of measurement . 9 8.1 Preparation of test sample . 9 8.2 Preparation of apparatus . 9 8.2.1 Cleaning procedure . 9 8.2.2 Temperature correction . 9 9 Measurement . 10 10 Calculation and Evaluation . 13 10.1 Automatic evaluation . 13 10.2 Manual evaluation . 15 11 Expression of results . 16 12 Precision . 16 12.1 General . 16 12.2 Repeatability, r . 16 12.3 Reproducibility, R . 16 13 Test report . 16 Annex A (informative)
Background of the method . 18 Annex B (informative)
Results of an Interlaboratory Study . 19 Bibliography . 20
SIST EN 14112:2016



EN 14112:2016 (E) 3 European foreword This document (EN 14112:2016) has been prepared by Technical Committee CEN/TC 307 “Oilseeds, vegetable and animal fats and oils and their by-products - Methods of sampling and analysis”, the secretariat of which is held by AFNOR. 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 2017, and conflicting national standards shall be withdrawn at the latest by March 2017. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN shall not be held responsible for identifying any or all such patent rights This document supersedes EN 14112:2003. Significant changes between this document and EN 14112:2003 are: a) the limitation of the scope of the method to a maximum induction period of 48 h, reflecting the precision range of the method; b) indication of a potential alteration of the induction period in the presence of cetane enhancers; c) editorial changes in order to clarify the test procedure; d) addition of Clause 2 – Normative references; e) addition of Clause 11 – Expression of results; f) background information on the method added as Annex A. 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 14112:2016



EN 14112:2016 (E) 4 Introduction This document is based on EN 14112:2003, which was specifically adapted for the determination of oxidation stability of fatty acid methyl esters (FAME). This method had been developed under CEN/TC 307 (Fats and oils). The modifications as given in this document address the field experience with this method made since its introduction as a standard test method. Editorial changes are made in order to specify some aspects of the test. Additionally, the cleaning procedure is modified based on field experience. SIST EN 14112:2016



EN 14112:2016 (E) 5 1 Scope This European Standard specifies a method for the determination of the oxidation stability of fatty acid methyl esters (FAME) at 110 °C, by means of measuring the induction period up to 48 h. NOTE 1 EN 15751 [1] describes a similar test method for oxidation stability determination of pure fatty acid methyl esters and of blends of FAME with petroleum-based diesel containing 2 % (V/V) of FAME at minimum. NOTE 2 The precision statement of this test method was determined in a Round Robin exercise with induction periods up to 8,5 h, thus covering the limit value in EN 14214. Results from precision studies on EN 15751 indicate that the precision statement is valid for induction periods up to 48 h but not for higher values. NOTE 3 Limited studies on EN 15751 with EHN (2-ethyl hexyl nitrate) on FAME blends indicated that the stability is reduced to an extent which is within the reproducibility of the test method. It is likely that the oxidation stability of pure FAMEs is also reduced in the presence of EHN when EN 14112 is used for testing. 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 ISO 3170, Petroleum liquids - Manual sampling (ISO 3170) EN ISO 3171, Petroleum liquids - Automatic pipeline sampling (ISO 3171) 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 induction period time which passes between the moment when the measurement is started and the moment when the formation of oxidation products begins to increase rapidly 3.2 oxidation stability induction period determined according to the procedure specified in this European Standard, expressed in hours 4 Principle A stream of purified (dried) air is passed through the sample which has been heated to the target temperature which is 110 °C in the usual application of the method. Volatile compounds are formed during the oxidation process. They are, passed together with the air into a flask containing demineralized or distilled water, equipped with a conductivity electrode. The electrode is connected to a measuring and recording device. It indicates the end of the induction period by rapid increase of the conductivity due to the dissociation of volatile carboxylic acids produced during the oxidation process and absorbed in the water. For more details on the background of the method see Annex A. SIST EN 14112:2016



EN 14112:2016 (E) 6 5 Reagents and materials Use only reagents of analytical grade and distilled or demineralized water. 5.1 Ternary solvent mixture, consisting of methanol/toluene/acetone 1:1:1 (by volume). 5.2 Alkaline laboratory glass cleaning solution. 5.3 2-Propanol. 6 Apparatus Usual laboratory equipment and glassware, together with the following: 6.1 Device for the determination of oxidation stability, comprising the following parts (see Figures 1 and 2) 1). 6.1.1 Air filter, comprising a tube fitted with filter paper at the ends and filled with a molecular sieve (6.6), connected to the suction end of a pump. 6.1.2 Gas membrane pump, with an adjustable flow rate of (10 ± 1,0) l/h. 6.1.3 Reaction vessels of borosilicate glass, provided with a sealing cap. The sealing cap shall be fitted with a gas inlet and outlet tube. 6.1.4 Closed measurement cells, of approximately 150 ml capacity, with an air inlet tube extending to the bottom inside of the vessel. The cell shall have ventilation holes at the top. 6.1.5 Electrodes, for measuring conductivity within a range of 0
300 dimensions of the measurement cell (6.1.4). 6.1.6 Measuring and recording apparatus, comprising: a) an amplifier; and b) a recorder registering the signal of each of the electrodes (6.1.5). 6.1.7 Thyristor and contact thermometer graduated in 0,1 °C or Pt 100 element to measure the block temperature, with attachments for relay connection and an adjustable heating element; temperature scale 0 °C to 150 °C.
1) Rancimat is the trade name of a product supplied by Metrohm AG, Herisau, Switzerland; OSI is the trade name of a product supplied by Omnion Inc., Rockland, Massachusetts, USA. This information is given for the convenience of users of this European Standard and does not constitute an endorsement by CEN or CENELEC of the products named. Equivalent products may be used if they can be shown to lead to the same results. SIST EN 14112:2016



EN 14112:2016 (E) 7 6.1.8 Heating block, made of cast aluminium, adjustable to a temperature up to (150 ± 0,1) °C. The block shall be provided with holes for the reaction vessels (6.1.3) and an aperture for the contact thermometer (6.1.7). Alternatively a heating bath may be used, filled with oil suitable for temperatures up to 150 °C, and adjustable to the nearest 0,1 °C. 6.2 Certified and calibrated thermometer or Pt100 element, with a temperature range up to 150 °C, graduated in 0,1 °C.
Key 1 air filter (6.1.1) 5 electrode (6.1.5) 2 gas membrane pump with flow rate control (6.1.2) 6 measuring and recording apparatus (6.1.6) 3 reaction vessel (6.1.3) 7 thyristor and contact thermometer (6.1.7) 4 measurement cell (6.1.4) 8 heating block (6.1.8) Figure 1 — Apparatus SIST EN 14112:2016



EN 14112:2016 (E) 8 Dimensions in mm
Key 1 measuring vessel 5 sample 2 electrode 6 heating block 3 distilled/demineralized water 7 air inlet 4 reaction vessel
Figure 2 — Diagrammatic representation of heating block, reaction vessel and measurement cell 6.3 Measuring pipettes and/or measuring cylinders. 6.4 Oven, adjustable to a temperature up to (150 ± 3) °C. 6.5 Connecting hoses, flexible and made of inert material [polytetrafluoroethylene (PTFE) or silicone]. 6.6 Molecular sieve, with moisture indicator, pore size 0,3 nm, dried in an oven set at 150 °C and cooled down to room temperature in a desiccator before use. 6.7 Balance, capable of weighing with an accuracy of ± 0,1 g or less. 7 Sampling Unless otherwise specified, sampling shall be conducted according to EN ISO 3170 or EN ISO 3171 and/or in accorda
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