SIST EN 1186-15:2003
(Main)Materials and articles in contact with foodstuffs - Plastics - Part 15: Alternative test methods to migration into fatty food simulants by rapid extraction into iso-octane and/or 95 % ethanol
Materials and articles in contact with foodstuffs - Plastics - Part 15: Alternative test methods to migration into fatty food simulants by rapid extraction into iso-octane and/or 95 % ethanol
This European Standard specifies two alternative test methods, in the sense of an extraction test with a 'more severe' test character, for the assessment of the overall migration into fatty food simulants.
Method A is based on the determination of the extraction of migrateable substances from plastics which are intended to come into contact with foodstuffs, by total immersion in non-polar, iso-octane, and/or polar, ethanol, solvents depending on the polarity of the packaging material. According to results obtained by this method (see [1],[2],[3],[4],[5],) and taking physio-chemical considerations into account, the obtained extraction efficiency has, generally, been found to be equivalent to or higher than overall migration results obtained under the test conditions, 10 days at 40 °C, 2 h at 70 °C, 1 h at 100 °C, 30 min at 121 °C and 30 min at 130 °C.
To ensure as complete as possible extraction of the potential migrants, a strong interaction, e.g. swelling, of the sample by the extraction solvent is necessary. For this purpose, iso-octane is used as an extraction solvent for plastics materials and articles containing non polar food contact layers, such as polyolefins. For test samples made from polar food contact plastics such as polyamide and polyethylene terephthalate, 95 % (v/v) aqueous ethanol is used. For polystyrenes, plasticized polyvinyl chloride and other polymers where the identification or polarity of the polymer is not clear, two parallel extraction tests should be conducted using both of the proposed extraction solvents and taking the higher value obtained as the relevant result.
NOTE 1 In case of multilayer structures such as plastics laminates and co-extruded plastics, the nature of the food contact layer determines the selection of the extraction solvent(s).
Werkstoffe und Gegenstände in Kontakt mit Lebensmitteln - Kunststoffe - Teil 15: Alternative Prüfverfahren zur Bestimmung der Migration in fettige Prüflebensmittel durch Schnellextraktion in iso-Octan und/oder 95%-iges Ethanol
Diese Europäische Norm legt zwei alternative Prüfverfahren für die Bewertung der Gesamtmigration in fettige Prüflebensmittel im Sinne einer Extraktionsprüfung mit größerer Prüfschärfe fest.
Verfahren A beruht auf der Bestimmung der Extraktion von migrierfähigen Substanzen aus Kunststoffen, die für den Kontakt mit Lebensmitteln bestimmt sind, durch völliges Eintauchen in unpolares (Iso-Octan) und/oder polares (Ethanol) Lösemittel in Abhängigkeit von der Polarität der Verpackung. Nach den mit diesem Verfahren erhaltenen Ergebnissen (siehe [1], [2], [3], [4], [5]) und unter Berücksichtigung physikalisch-chemischer Überlegungen, hat sich die erhaltene Extraktionseffiziens im Allgemeinen als gleichwertig oder höher herausgestellt als die Ergebnisse der Gesamtmigration unter folgenden Prüfbedingungen: für eine Zeitdauer von 10 Tagen bei einer Temperatur von 40 °C, von 2 h bei 70 °C, von 1 h bei 100 °C, von 30 min bei 121 °C und von 30 min bei 130 °C.
Um eine möglichst vollständige Extraktion sicherzustellen, ist eine starke Wechselwirkung (z. B. Aufquellen) der Probe mit dem Lösemittel erforderlich. Zu diesem Zweck wird Iso-Octan als Lösemittel für Werkstoffe und Gegenstände aus Kunststoff mit einer unpolaren, mit Lebensmitteln in Kontakt kommenden Schicht, wie z. B. Polyolefine, verwendet. Für Prüfproben aus polaren Kunststoffen, die in Kontakt mit dem Lebensmittel kommen, wie z. B. Polyamid und Polyethylenterephtalat, wird eine 95%-ige wässrige Ethanollösung verwendet. Bei Polystyrolen, weichem Polyvinylchlorid und anderen Polymeren, bei denen die Polarität des Polymers nicht eindeutig festgestellt ist, sollten zwei parallele Extraktionsprüfungen unter Verwendung beider vorgeschlagener Lösemittel durchgeführt werden, wobei der höhere erhaltene Wert als zutreffendes Ergebnis genommen wird.
Matériaux et objets en contact avec les denrées alimentaires - Matiere plastique - Partie 15: Méthodes de remplacement pour la vérification de la migration dans les simulants gras par extraction rapide dans l'iso-octane et/ou l'éthanol aqueux a 95 %
La présente partie de la Norme européenne spécifie deux méthodes dites " de remplacement " comportant un essai d'extraction de nature " plus sévere " pour vérifier la migration globale dans les simulants gras.La méthode A repose sur la détermination de l'extraction des substances potentiellement migrantes provenant des matieres plastiques destinées a entrer en contact avec les denrées alimentaires, apres immersion totale dans des solvants non polaires (comme l'iso-octane) ou polaires (comme l'éthanol), selon la polarité du matériau de conditionnement. Compte tenu des résultats donnés par la méthode (voir [1], [2], [3], [4], [5]) et des caractéristiques physico-chimiques, il s'est avéré que les rendements d'extraction obtenus étaient généralement équivalents ou supérieurs a ceux donnés par les essais de migration globale obtenus dans les conditions d'essai suivantes : 10 jours a 40 °C, 2 h a 70 °C, 1 h a 100 °C, 30 min a 121 °C et 30 min a 130 °C.Pour assurer une extraction aussi complete que possible des migrants potentiels, il est nécessaire d'avoir une forte interaction (par exemple gonflement) entre l'échantillon et le solvant d'extraction utilisé. C'est la raison pour laquelle on utilise de l'iso-octane comme solvant d'extraction pour les matériaux et objets en plastiques multicouches a couche de contact non polaire, tels les polyoléfines, et de l'éthanol en solution aqueuse a 95 % (v/v) pour les échantillons en plastiques a couche de contact polaire, tels le polyamide ou le polyéthylene téréphtalate. Pour les polystyrenes, le chlorure de polyvinyle plastifié ou d'autres polymeres dont l'identification ou la polarité n'est pas claire, il convient de mener deux extractions en parallele avec les deux solvants d'extraction proposés et de retenir comme résultat celui qui donne la valeur la plus élevée.NOTE 1 Dans le cas de structures multicouches telles que les plastiques stratifiés ou co-extrudés, c'est la nature de la couche de contact avec les denrées alimentaire
Materiali in predmeti v stiku z živili - Polimerni materiali - 15. del: Alternativne preskusne metode za migracijo v modelne raztopine za maščobna živila s hitro ekstrakcijo z izooktanom in/ali 95-odstotnim etanolom
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2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Werkstoffe und Gegenstände in Kontakt mit Lebensmitteln - Kunststoffe - Teil 15: Alternative Prüfverfahren zur Bestimmung der Migration in fettige Prüflebensmittel durch Schnellextraktion in iso-Octan und/oder 95%-iges EthanolMatériaux et objets en contact avec les denrées alimentaires - Matiere plastique - Partie 15: Méthodes de remplacement pour la vérification de la migration dans les simulants gras par extraction rapide dans l'iso-octane et/ou l'éthanol aqueux a 95 %Materials and articles in contact with foodstuffs - Plastics - Part 15: Alternative test methods to migration into fatty food simulants by rapid extraction into iso-octane and/or 95 % ethanol67.250Materiali in predmeti v stiku z živiliMaterials and articles in contact with foodstuffsICS:Ta slovenski standard je istoveten z:EN 1186-15:2002SIST EN 1186-15:2003en01-januar-2003SIST EN 1186-15:2003SLOVENSKI
STANDARD
SIST EN 1186-15:2003
EUROPEAN STANDARDNORME EUROPÉENNEEUROPÄISCHE NORMEN 1186-15September 2002ICS 67.250English versionMaterials and articles in contact with foodstuffs - Plastics - Part15: Alternative test methods to migration into fatty foodsimulants by rapid extraction into iso-octane and/or 95 %ethanolMatériaux et objets en contact avec les denréesalimentaires - Matière plastique - Partie 15: Méthodesd'essai alternatives pour la migration dans les simulantsalimentaires gras par extraction rapide dans l'iso-octaneet/ou l'éthanol à 95 %Werkstoffe und Gegenstände in Kontakt mit Lebensmitteln- Kunststoffe - Teil 15: Alternative Prüfverfahren zurMigration in fettige Prüflebensmittel durch Schnellextraktionin Iso-Octan und/oder 95%iges EthanolThis European Standard was approved by CEN on 29 April 2002.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,Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMITÉ EUROPÉEN DE NORMALISATIONEUROPÄISCHES KOMITEE FÜR NORMUNGManagement Centre: rue de Stassart, 36
B-1050 Brussels© 2002 CENAll rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN 1186-15:2002 ESIST EN 1186-15:2003
EN 1186-15:2002 (E)2ContentspageForeword.31Scope.42Normative references.53Method A Alternative test method to migration into fatty food simulants by rapid extractioninto iso-octane and/or 95 % ethanol by total immersion.54Method B Alternative test method to migration into fatty food simulants by rapid extractioninto iso-octane and/or 95 % ethanol in the single side mode by cell.10Annex ZA (informative)
Relationship of this European Standard with Council Directive 89/109/EECand Commission Directive 90/128/EEC and associated Directives.15Bibliography.17SIST EN 1186-15:2003
EN 1186-15:2002 (E)3ForewordThis document EN 1186-15:2002 has been prepared by Technical Committee CEN/TC 194 “Utensils in contactwith food”, the secretariat of which is held by BSI.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 March 2003, and conflicting national standards shall be withdrawn at the latest byMarch 2003.This European Standard has been prepared as one of a series of methods of test for plastics materials and articlesin contact with foodstuffs.For relationship with EU Directive(s), see informative annex ZA, which is an integral part of this document.At the time of preparation and publication of this standard the European Union legislation relating to plasticsmaterials and articles intended to come into contact with foodstuffs is incomplete.
Further Directives andamendments to existing Directives are expected which could change the legislative requirements which thisstandard supports.
It is therefore strongly recommended that users of this standard refer to the latest relevantpublished Directive(s) before commencement of any of the test or tests described in this standard.EN 1186-15 should be read in conjunction with EN 1186-1.Further parts of this standard have been prepared concerned with the determination of overall migration fromplastics materials into food simulants.
Their titles are as follows:EN 1186 Materials and articles in contact with foodstuffs – Plastics –Part 1Guide to the selection of conditions and test methods for overall migrationPart 2Test methods for overall migration into olive oil by total immersionPart 3Test methods for overall migration into aqueous food simulants by total immersionPart 4Test methods for overall migration into olive oil by cellPart 5Test methods for overall migration into aqueous food simulants by cellPart 6Test methods for overall migration into olive oil using a pouchPart 7Test methods for overall migration into aqueous food simulants using a pouchPart 8Test methods for overall migration into olive oil by article fillingPart 9Test methods for overall migration into aqueous simulants by article fillingPart 10Test methods for overall migration into olive oil (modified method for use in cases whereincomplete extraction of olive oil occurs)Part 11Test methods for overall migration into mixtures of
14C-labelled synthetic triglyceridePart 12Test methods for overall migration at low temperaturesPart 13Test method for overall migration at high temperaturesPart 14Test methods for 'substitute tests' for overall migration from plastics intended to come intocontact with fatty foodstuffs using test media iso-octane and 95 % ethanolAccording 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, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Spain,Sweden, Switzerland and the United Kingdom.SIST EN 1186-15:2003
EN 1186-15:2002 (E)41 ScopeThis European Standard specifies two alternative test methods, in the sense of an extraction test with a 'moresevere' test character, for the assessment of the overall migration into fatty food simulants.Method A is based on the determination of the extraction of migrateable substances from plastics which areintended to come into contact with foodstuffs, by total immersion in non-polar, iso-octane, and/or polar, ethanol,solvents depending on the polarity of the packaging material.
According to results obtained by this method (see[1], [2], [3], [4], [5]) and taking physio-chemical considerations into account, the obtained extraction efficiency has,generally, been found to be equivalent to or higher than overall migration results obtained under the test conditions,10 days at 40 °C, 2 h at 70 °C, 1 h at 100 °C, 30 min at 121 °C and 30 min at 130 °C.To ensure as complete as possible extraction of the potential migrants, a strong interaction, e.g. swelling, of thesample by the extraction solvent is necessary.
For this purpose, iso-octane is used as an extraction solvent forplastics materials and articles containing non polar food contact layers, such as polyolefins.
For test samples madefrom polar food contact plastics such as polyamide and polyethylene terephthalate, 95 % (v/v) aqueous ethanol isused.
For polystyrenes, plasticized polyvinyl chloride and other polymers where the identification or polarity of thepolymer is not clear, two parallel extraction tests should be conducted using both of the proposed extractionsolvents and taking the higher value obtained as the relevant result.NOTE 1In case of multilayer structures such as plastics laminates and co-extruded plastics, the nature of the food contactlayer determines the selection of the extraction solvent(s).This test method should only be applied to flexible packagings which are less than 300 µm in thickness. When theresult does not exceed the allowed overall migration limit then the material can be considered to be in compliancewith EC regulations.
If the test result exceeds the allowed overall migration limit the following options may beapplied chronologically with respect to further migration testing:1) single-sided extraction test using a cell, if technically feasible (see clause 4 Method B of this standard);2) conventional migration test using olive oil or other fatty food simulants;NOTE 2The overall migration limit is specified in Commission Directive 90/128/EEC [7] and the conditions of test in CouncilDirective 82/711/EEC [8] and its subsequent amendments, [9], [10].Method B is applicable in those cases where the total immersion test, EN 1186-15 Method A, yields total extractionvalues that exceed the overall migration or may be technically unsuitable, i.e. in the case of multilayer structures,such as plastics laminates and co-extruded films.
This test method should primarily only be applied to flexiblepackagings with a physical barrier layer (for instance of aluminium or other material to prevent penetrative loss ofextraction solvent) and which have a thinner food contact layer than 300 µm.
If the result does not exceed theallowed overall migration limit then the material can be considered to be in compliance with EC regulations.
If thetest result exceeds the allowed overall migration limit then the following option may be applied with respect tofurther migration testing:-
conventional migration test using olive oil or other fatty food simulants.NOTE 3Methods A and B are not applicable to test materials intended for applications over 130 °C.NOTE 4Test materials intended for applications over 70 °C should be checked for their physical suitability at the intendedtime and temperature of use.SIST EN 1186-15:2003
EN 1186-15:2002 (E)52 Normative referencesThis European Standard incorporates by dated and undated reference, provisions from other publications.
Thesenormative references are cited at the appropriate places in the text, and the publications are listed hereafter.
Fordated references, subsequent amendments to and revisions of any of these publications apply to this EuropeanStandard only when incorporated in it by amendment or revision.
For undated references the latest edition of thepublication referred to applies (including amendments).EN 1186-1:2002, Materials and articles in contact with foodstuffs – Plastics – Part 1: Guide to the selection ofconditions and test methods for overall migration.ISO 648, Laboratory glassware - One mark pipettes.ISO 4788, Laboratory glassware - Graduated measuring cylinders.3 Method AAlternative test method to migration into fatty food simulants by rapid extraction into iso-octane and/or 95 % ethanol by total immersion3.1 PrincipleThe migrateable substances extracted from a sample of the plastics is determined as the mass of non-volatileresidue after evaporation of the solvent following immersion.
Test specimens of at least 1 dm² (single sideconsidered) are immersed in the extraction solvent for 24 h at 40 °C or 50 °C and then removed.
The extractionsolvent is evaporated to dryness, the mass of the non-volatile residue is determined and expressed as milligramsper square decimetre of surface area of the test specimen.
The measured value is compared to the EC-officialoverall migration limit and taking the analytical tolerance of this method (± 1 mg/dm²) into account.3.2 ReagentsNOTEFor details of preparation and quality of these reagents, see clause 5 of EN 1186-1:2002.3.2.1 Ethanol 95 % (v/v) in aqueous solution.3.2.2 Iso-octane (2,2,4-trimethylpentane)NOTEThe extraction solvents given in 3.2.1 and 3.2.2 are selected according to the nature of the polymer test sample asgiven by Table 1, see 3.5.1.SIST EN 1186-15:2003
EN 1186-15:2002 (E)63.3 Apparatus3.3.1 Cutting slab, clean smooth glass, metal or plastics slab of suitable area to prepare test specimens,250 mm ´ 250 mm is suitable.3.3.2 Tweezers, stainless steel, blunt nosed.3.3.3 Cutting implement, scalpel, scissors or sharp knife or other suitable device.3.3.4 Metal template, (100 mm ± 0,2 mm) ´ (100 mm ± 0,2 mm) (square).3.3.5 Rule, graduated in mm, and with an accuracy of 0,1 mm.3.3.6 Analytical balance capable of determining a change in mass of 0,1 mg.3.3.7 Extraction containers; glass weighing jars with ground joints, tall form, of a capacity of approx. 60 ml.3.3.8 Thermostatically controlled oven or incubator capable of maintaining a temperature within the range of+ 40 °C to + 50 °C and meeting temperature tolerance values within those specified for the test temperature, seeannex B of EN 1186-1:2002.WARNINGThe interior / sample space of the oven or incubator should not have any exposed heating elements, to minimisesafety hazards arising from any loss of flammable test media during the test period.3.3.9 Dishes, of stainless steel, nickel, platinum, platinum alloy or gold, 50 mm to 90 mm diameter and ofmaximum mass 100 g, for evaporation of solvents and weighing of residues.
Glass, glass ceramic, ceramic oraluminium dishes may be used provided that their surface characteristics are such that the mass of the dishes afterevaporation of any specified solvent followed by conditioning in the desiccator used achieves a constancy of± 0,5 mg.3.3.10 Steam bath, hot plate, distillation apparatus or rotary evaporator.3.3.11 Desiccator with anhydrous calcium chloride or self indicating silica gel.3.3.12 Measuring cylinder, 50 ml capacity, conforming to the minimum requirements of ISO 4788.3.3.13 Round-bottom flask, 250 ml capacity [for distillation method (see 3.5.3.3) only].3.4 Preparation of test specimens3.4.1 GeneralIt is essential that test specimens are clean and free from surface contamination (many plastics can readily attractdust due to static charges).
Before preparing test specimens, remove any surface contamination from the sampleby gently wiping it with a lint free cloth, or by brushing with a soft brush.
Under no circumstances wash the samplewith water or solvent.
If it is specified in the instructions for use of the article that it should be washed or cleanedbefore use see 9.1 of EN 1186-1:2002.
Minimize handling of the samples and where necessary, wear cottongloves.To ensure that test pieces are well separated and that the surfaces are freely exposed to the extractant during theperiod of the test, insert a piece of fine stainless steel gauze between the cut test pieces.3.4.2 Number of test specimensThree replicate test specimens are required.SIST EN 1186-15:2003
EN 1186-15:2002 (E)73.4.3 Cutting and preparation of specimenLay the sample on the cutting slab (3.3.1) and cut the test specimens of 1 dm² (see 9.3 of EN 1186-1:2002), usingthe 100 mm ´ 100 mm template (3.3.4).
Check, using the rule (3.3.5), that the dimensions of the specimen arewithin the specified tolerance (1 mm).
Fold the test specimens into a fan-like shape or cut into strips approximately2 cm wide and 5 cm long.
Place in the extraction containers (3.3.7).3.5 Procedure3.5.1 Selection of extraction solventSelect the appropriate extraction solvent(s) (see 3.2.1 and 3.2.2) according to the nature of the polymer test sampleas given in Table 1.Table 1 — Use of extraction solvents and test conditions – Method APolymer type of food contact layerExtraction solvent to beappliedExtraction conditions to beappliedPolyolefines and copolymersPolyamidesPolystyrenePolyethylene terephthalatePolyvinyl chloride (plasticized)Polyvinyl chloride (rigid)iso-octane95 % ethanoliso-octane and 95 % ethanol 95 % ethanoliso-octane and 95 % ethanol95 % ethanol24 h at 40 °C24 h at 40 °C24 h at 40 °C24 h at 50 °C24 h at 40 °C24 h at 50 °C3.5.2 Exposure to solventTake three extraction containers or jars (3.3.7), measure by measuring cylinder (3.3.12) 50 ml of the solvent intoeach of these jars and immerse the test specimens in the solvent.
Ensure that the test specimens are totallyimmersed in the solvent.
If the evaporation method is to be used (3.5.3.2) measure into a further two jars bymeasuring cylinder the same amount of solvent, plus 10 ml ± 2 ml, to provide blanks.
If the distillation method(3.5.3.3) is to be used measure into those further two jars by measuring cylinder the same amount of solvent incontact with the test specimens to provide blanks.
Stopper the jars.
Mark the jars for identification.
Mark the liquidlevel on the outside of each jar with a suitable marker.The extraction conditions are to be selected from Table 1 according to the nature of the polymer test samples.SIST EN 1186-15:2003
EN 1186-15:2002 (E)8Place the five jars in the thermostatically controlled oven or incubator (3.3.8), set at the test temperature andobserve the temperature, leave the jars for the test period of 24 h after the air bath of the thermostatically controlledoven or incubator has reached the set temperature and taking the permitted time and temperature tolerances intoaccount (see annex B of EN 1186-1:2002).
Take the jars from the oven or incubator and allow them to cool downto room temperature.
Check the level of solvent in each.
If this has fallen to more than 5 mm below the mark, orhas exposed any part of the test pieces, repeat the test using fresh test specimens.
If the level of solvent in a jar isless than 5 mm below the mark, remove the test specimen from the jar, and allow the solvent adhering to the testspecimen and support to drain back into the jar. Recover at least 90 % of the original volume of solvent, includingthe blanks, or repeat the test.WARNINGBoth iso-octane and ethanol are volatile flammable solvents.
Care should be taken to avoidany loss of solvent into the interior of the thermostatting device.
Place the jars, if possible, in a dripcontainer serving as a possible solvent reservoir in case of leakage.
Do not allow the temperature toexceed 60 °C.3.5.3 Determination of extracted substances3.5.3.1 Preparation of dishesTake five dishes (3.3.9), marked for identification, place the dishes in an oven maintained at 105 °C to 110 °C, for aperiod of 30 min ± 5 min, to dry.
Remove the dishes from the oven, place in a desiccator and allow to cool toambient temperature.
Weigh and record the individual masses of each dish.
Replace the dishes in the oven andrepeat the cycle of heating, cooling and weighing until individual consecutive masses differ by not more than0,5 mg.
Record their final masses.3.5.3.2 Evaporation methodFor each jar, including the two blank jars,containing the solvent, pour 20 ml to 25 ml into a prepared dish.
Bymeans of a steam bath, hot plate or other form of heating evaporate to a low volume (3.3.10), taking care to avoidloss of residue, in particular, by sputtering or overheating.NOTE 1The evaporation should be carried out in a fume cupboard.When most of the solvent has evaporated, pour the remaining solvent from each of the jars into the respectivedishes and continue the evaporation.
Rinse each of the jars which had contained test specimens with two lots of5 ml ± 1 ml of fresh solvent and pour these washings into the respective dishes.
Continue the evaporation.NOTE 2A stream of nitrogen can be used to facilitate evaporation.When the solvent has almost completely evaporated, place the dish in an oven maintained at 105 °C to 110 °C, fora period of 30 min ± 5 min, to complete the evaporation and dry the residue.
Remove the dishes from the oven,place in a desiccator (3.3.11) and allow to cool to ambient temperature.
Weigh and record the individual masses ofeach dish and residue.
Replace the dishes in the oven and repeat the cycle of heating, cooling and weighing untilindividual consecutive masses differ by not more than 0,5 mg.
Determine the mass of the residue by subtractingthe original mass of the dish from the final mass of the dish and residue.3.5.3.3 Distillation methodFor each jar, transfer the contents to a round bottom flask (3.3.13).
Rinse each jar twice, including the blank jars,with 20 ml ± 2 ml of fresh solvent, add these rinses to the respective flasks.
Place the flasks in an electric heatingmantle and connect to a side arm distillation arrangement or rotary evaporator.
Distil off the solvents untilapproximately 15 ml to 25 ml remains in the flask.
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