1、StabilityStability Measuring InstrumentsStability Measuring Instruments743 Rancimat763 PVC ThermomatUwe LoyallMetrohm Ltd.CH-9100 HerisauSwitzerlandStabilityRancidityPrinciple of Rancimat methodEvaluationInfluences on the determinationTemperature ExtrapolationGLP-Validation of the instrumentThe 743
2、RancimatApplications Rancimat763 PVC ThermomatPVC ApplicationsOverviewOverviewStabilityRancidityRancidityhydrolytic rancidityoxidative rancidityStabilityHydrolytic RancidityHydrolytic RancidityCH2CHCH2OOHOOO+CH3(CH2)nCOOHtriglycerideenzymesCH2CHCH2OOOOOO+H2Odiglyceridefatty acidStabilityHydrolytic R
3、ancidityHydrolytic Rancidityuse only dry air for Rancimat measurementsStabilityOxidative RancidityOxidative RancidityRadical chain reaction:Radical chain reaction:Initiation?RH?R.Propagation?R.+O2?RO2.?ROO.+RH?R-OOH+R.Termination?R.+R.?R-R?ROO.+R.?R-OO-RStabilityOxidative RancidityOxidative Rancidit
4、yPrimary reaction products:?Peroxides(R-OO-R)?Hydroperoxides(R-OOH)?unstableSecondary reaction products:?Aldehydes?Alcohols?Carbonic acidsStabilityFactors Accelerating OxidationFactors Accelerating OxidationOxygenHeavy metal ions(e.g.Fe,Cu)?catalyse chain initiationUV lightStabilityAntioxidantsAntio
5、xidantsChain breaking substances?E.g.phenolic compounds?Examples?natural compounds?synthetic antioxidants:BHA,BHT,TBHQ,.?TocopherolComplexing agents?citric acid,phosphoric acid,ascorbic acid,.UV deactivators?phenyl salicylate,hydroxybenzophenoneStabilityLimitations for Limitations for measurement of
6、 antioxidant activitymeasurement of antioxidant activityVolatile antioxidantsAntioxidants unstable at high temperaturesStabilityPrinciple ofPrinciple of RancimatRancimat MethodMethodStabilityQuality Assessment of Fats/OilsQuality Assessment of Fats/OilsRancimat test=accelerated oxidation test?at ele
7、vated temperature?under exposure of airfaster autoxidation in a few hours instead of weeks/monthsStabilityPrinciple of Principle of RancimatRancimat MethodMethodfatty acids are oxidised by oxygen from airlow molecular organic acids are formedorganic acids stripped out of the oil by air flowStability
8、heating block(e.g.120C)oil samplereaction vesselair inletmeasuring vesselconductivity cellabsorption solution(water)Principle of Principle of RancimatRancimat MethodMethodStabilityRancimatRancimat CurveCurve 10.53 10.78 01020304050607001234567891011礢/cmhInduction period:oxidation of fatty acids?pero
9、xide formationslow reactionno formation of volatile carboxylic acidsaccelerated fast reactionoxidation of fatty acids?formation of volatile carboxylic acidsStabilityEvaluationEvaluationStabilityRancimatRancimat CurveCurve 10.53 10.78 01020304050607001234567891011S/cmhinduction time10.53stability tim
10、e10.78StabilityEvaluation of Induction TimeEvaluation of Induction Time 10.53 10.78 01020304050607001234567891011礢/cmh 10.53 10.78 01020304050607001234567891011/cm礢h2ndderivative of measured curve?shows maximum=induction timeStabilityEvaluation of Stability TimeEvaluation of Stability Time 10.53 10.
11、78 01020304050607001234567891011礢/cmhabsolute increase in conductivity in the absorption solution=50 S/cmStability 10.53 10.78 01020304050607001234567891011礢/cmh 10.27 10.78 01020304050607001234567891011礢/cmhReevaluationReevaluationAutomatic result can be modifiedTangent method(only manual)Stability
12、Influences on the determinationInfluences on the determinationTemperature ExtrapolationTemperature ExtrapolationTemperatureGas flowSample weightStabilityInfluences on the resultsInfluences on the resultsTemperature:?10C increase?50%induction time?max.deviation of temperature:0.3C?stability of temper
13、ature 0.1C?exact temperature adjustment importantGas flow:?small influence?no changes within 10%flow changeSample weight:?small influence?cooling effect depending on the sample weightStabilityTemperature CalibrationTemperature CalibrationNecessary equipment:?GLP set?with certified temperature sensor
14、Control of the accuracy of the heating blockDetermination of the temperature correction?for each temperature?for each heating block?each gas flowStabilityTemperature DependencyTemperature Dependencysample at different temperaturesStabilityTemperature ExtrapolationTemperature Extrapolationevaluation
15、of dependency:temperature vs.induction timetemperaturelog(induction time)T=f(t)(TBeAt=StabilityExtrapolationExtrapolationStandard factor=temperature coefficient:change of induction time per 10Ctheoretical value=2estimated shelf life timeStabilityThe 743 RancimatThe 743 RancimatStabilityThe new PC co
16、ntrolled The new PC controlled RancimatRancimat8 samples2 temperaturesup to 4 Rancimats/Thermomats per PCStabilitySingle Button Single Button-Single ConnectionSingle Connectionoptional:calibrated external Temperature Sensorconnection to PCStabilityInternal or external Air SupplyInternal or external
17、Air Supplyonly RancimatStabilityOperationOperationDisposable reaction vessels and gas inlet tubes?no time-consuming cleaningno fragile and expensive glasswareOne-piece measuring vessel cover and conductivity cellStabilityConductivity CellConductivity CellCell constant:1.1 cm-1(0.1)StabilityFeaturesF
18、eatures743 Rancimat is controlled by PC(WindowsTM95/98/NT/2000/XP)8 samples per Rancimat in 2 independent heating blocks(2 temperatures per Rancimat)up to 4 Rancimat units may be attached to 1 PC(32 Samples)every channel may be handled independentlyTemperature range:50.220 CStability of temperature:
19、improved result accuracy.StabilityInstrument OperationInstrument OperationStabilityMain ScreenMain ScreenStart/StopheatingStart/Stop determinationLive displayMethod settingsStabilityParametersParametersFor oils and fats100 140CTabled value(see manual)?Determine with external temperature sensorSee ta
20、b EvaluationStabilityEvaluationEvaluation 1.45 051015202530354045500.000.250.500.751.001.251.501.75 S/cmhInduction time=maximum of 2ndderivativeabsolute increasein conductivityStabilityFormulasFormulasStabilityStandardsStandards?Extrapolation functionTheoretical factor 2FreeFixed to 110C(AOCS)97.8C(
21、AOM)StabilityPreparing determinationPreparing determinationSelect method and modify parameters if necessaryStart heating?45 min to 120C?60 min to 220CPrepare measuring vessel?Low conductivity of the distilled water(5 S/cm)?Check conductivity cells(cell constant 1.0 1.2)?Replace plastic beakers(10 20
22、 determinations)Prepare reaction vessel?Remove particles(cardboard box,cullet,.)?Position of the air inlet tubeStabilityWhen temperature is reachedWhen temperature is reachedPlace measuring vesselConnect tubingsInsert reaction vessel Start determination immediatelyStabilityResultsResultsStabilityGLP
23、GLPValidation of the instrumentValidation of the instrumentStabilityGLP GLP Hardware ValidationHardware ValidationAutomatic Monitoring:?Temperature?Conductivity?Gas flowGLP Properties GLP Status InformationStabilityGLP Test TemperatureGLP Test TemperatureStabilityGLP Test ConductivityGLP Test Conduc
24、tivityStabilityApplicationsApplications RancimatRancimatStabilityApplications Applications RancimatRancimatOxidative stability of pure edible fats and oils from plants or animalsOxidative stability of natural fats and oils from food or cosmetics after extraction with petrol etherAntioxidant research
25、Oxidative stability of FAME(fatty acid methyl ester,biodiesel)Oxidation stability of light heating oil with Cu catalystStabilityRancimat Applications 1Rancimat Applications 1Oxidation Stability of Edible Fats and OilsOxidation Stability of Edible Fats and OilsAnimal fats/oils:?Butter,fish oil,lard,e
26、tc.Vegetable fats/oils:?soybean,sunflower,coconut,peanut,palmFat/oil containing products?direct measurements:margarine?after extraction of the fat:meat,nuts,etc.Antioxidant researchStability InduktionszeitStabilittszeit051015202530354045500.02.55.07.510.012.515.017.520.022.5S/cmhsesam oil/sesam oil/
27、sesam oil/sesam oil/sesam oil/sesam oil/sesam oil/sesam oil/Sesame OilSesame Oil4 temperatures:100C,110C,120C,130CStability102030405060708090100110120130140101102103104Chestimated life time at 20C:1.2 yearsSesame OilSesame Oil4 temperatures:100C,110C,120C,130CStability Induction timeStability time0.
28、02.55.07.510.012.515.017.564.1 S/c mhOlivenoel/Olivenoel/Olivenoel/olive oil/Olive OilOlive Oil4 temperatures:100C,110C,120C,130CStability102030405060708090100110120130140101102103ChOlive OilOlive Oil4 temperatures:100C,110C,120C,130Cestimated life time at 20C:0.7 yearsStabilityStandardsStandardsISO
29、 6886?Animal and vegetable fats and oils Determination of oxidation stabilityAOCS Cd 12b-92?Sampling and analysis of commercial fats and oils:Oil Stability IndexAOM-Active oxygen method2.4.28.4-93?Fat stability test on Autoxidation.CDM,JapanStabilityInformation on ApplicationsInformation on Applicat
30、ionsApplication Bulletins?204,141,232,237Application Notes?R-1,R-3,R-4,R-5,R-6,R-7Reprint?A modern method of determining the oxidative stability of fats and oils(679)?Comparison AOM-RancimatStabilityAOM AOM RancimatRancimat methodmethodComparison Rancimat-AOM0510152025303505101520253035Induction tim
31、e Rancimat hInduction time AOM hStabilityReprint:AntioxidantsReprint:AntioxidantsPublished inPublished inFood Marketing Food Marketing&Technology&TechnologyAugust 2002August 2002StabilityRancimat Applications 2Rancimat Applications 2Oxidation Stability of FAME/BiodieselOxidation Stability of FAME/Bi
32、odieselFAME=fatty acid methyl esterreplaces mineral oil based fuels(i.e.diesel)produced?from vegetable oils(e.g.canola oil,soybean oil)?by transesterification subsidized by government in some countriesquality control(oxidative stability)by Rancimat method?EN 14112StabilityProduction of FAMEProductio
33、n of FAMECH2CHCH2OHOHOHCH3OO+3triglyceridecatalystCH2CHCH2OOOOOO+3 CH3OHglycerolfatty acid methyl ester(FAME)fatty acid methyl ester(FAME)methanolStabilityFAME:Temperature DependencyFAME:Temperature Dependencytemperatures from 60-130C 010203040506070809010050100150200250300S/cmhRME+AO,RA-73-1/60CRME
34、AO,RA-73-1/60CRME+AO,RA-73-1/70CRME+AO,RA-73-1/70CRME+AO,RA-73-1/80 CRME+AO,RA-73-1/80 CRME+AO,RA-73-1/90CRME+AO,RA-73-1/90CRME+AO,RA-73-1/100CRME+AO,RA-73-1/100CRME+AO,RA-73-1/110CRME+AO,RA-73-1/110CRME+AO,RA-73-1/120CRME+AO,RA-73-1/120CStabilityFAME:Temperature DependencyFAME:Temperature Dependen
35、cyStabilityInformation on ApplicationsInformation on ApplicationsApplication Note R-9Standard EN 14112?Fatty Acid Methyl Esters(FAME)Determination of oxidation stability(Accelerated oxidation test)StabilityRancimatRancimat Applications 3Applications 3Oxidative stability of light heating oilOxidative
36、 stability of light heating oilwith Cu catalystHeating oil and heating oil with additive 0123456789100,02,55,07,510,012,515,0 S/cmhHeizl EL+Additiv,RA-74-2/135CHeizl EL+Additiv,RA-74-2+Sperre/135CHeizl EL,RA74-1/135CHeizl EL,RA74-1+Sperre/135CStabilityApplication InformationApplication InformationAp
37、plication Works?D7-078-0700?D7-082-0201 Stability763 PVC Thermomat763 PVC ThermomatStabilityheating block(e.g.120C)oil samplereaction vesselair inletmeasuring vesselconductivity cellabsorption solution(water)Principle of Principle of RancimatRancimat MethodMethodStabilityheating block(e.g.180C)PVC s
38、amplereaction vesselnitrogen inletmeasuring vesselconductivity cellabsorption solution(water)Principle of PVC Principle of PVC ThermomatThermomat MethodMethodStabilityPrinciple of PVCPrinciple of PVC ThermomatThermomatHCl formed due to thermal decomposition of PVCHCl stripped out by nitrogenStabilit
39、yPVCPVC ThermomatThermomat CurveCurve 10.53 10.78 01020304050607001234567891011礢/cmhStabilizer consumption:stabilizers inhibit HClformationPVC resin in staying unchangedNo stabilizer remainingfast decomposition of PCV resin?formation of HClgasStabilityHighlightsHighlights8 samples per unit at 2 temp
40、eraturesEvery channel may be handled independentlyDisposable glasswareHardware validation/GLP functionManual reprocessing Temperature extrapolation?estimation of life timeStabilityFeaturesFeatures763 PVC Thermomat is controlled by PC(WindowsTM95/98/NT/2000/XP)8 samples per PVC Thermomat in 2 indepen
41、dent heating blocks(2 temperatures per PVC Thermomat)up to 4 PVC Thermomat units may be attached to 1 PC(32 Samples)every channel may be handled independentlyTemperature range:50.220 CStability of temperature:0.1 CHardware Validation-GLP Function?improved result accuracy.StabilityInfluences on the P
42、VC resultsInfluences on the PVC resultsTemperature:?10C increase?50%induction time?exact temperature adjustment importantGas flow:?small influenceSample weight:?small influence?cooling effect depending on the sample weightCell constants?Stability time=absolute change in conductivity?calibration nece
43、ssaryStabilityPVC ApplicationsPVC ApplicationsStabilityPVC ApplicationsPVC ApplicationsDetermination of PVC stability times?Raw PVC?PVC products Examination of PVC additives?Stabilizers?PlasticizersProduction and Quality Control in PVC IndustryStability InduktionszeitStabilittszeit025507510012515017
44、520001234567S/cmhPVC Vergleichsprobe 1229.130/180 CPVC Vergleichsprobe 1229.130/180 CPVC Vergleichsprobe 1229.130/180 CPVC Vergleichsprobe 1229.130/180 CPVC/FS 67-2038PVC/FS 67-2038PVC/FS 67-2038PVC/FS 67-2038Pure and Blended PVCPure and Blended PVCStability InduktionszeitStabilittszeit0102030405060
45、7080901001100.00.51.01.52.02.5S/cmhSJ 2/A4SJ 2/A3J2/B2J2/B1J/J/raw,blended,processed PVCPure and Blended PVCPure and Blended PVCStabilityDifferent Batches of Raw PVCDifferent Batches of Raw PVC InduktionszeitStabilit鋞szeit051015202530354045500.00.10.20.30.40.50.60.70.8礢/cmhPVC 170 癈/FS 67-107 PVC 17
46、0 癈/FS 67-107 PVC 170 癈/FS 67-107 PVC 170 癈/FS 67-107 PVC 170 癈/FS 67-107PVC 170 癈/FS 70-294 PVC 170 癈/FS 70-294 PVC 170 癈/FS 70-294 PVC 170 癈/FS 70-294StabilityInformation on ApplicationsInformation on ApplicationsApplication Bulletin 205Application Note R-8StabilityStandards PVC Standards PVC Ther
47、mostabilityThermostabilityDIN 53381 part 1?Determination of the thermostability of PVCDIN VDE 0472 part 614?Examination of insulated cables-ThermostabilityISO 182-3?Plastics Determination of the tendency of PVC based polymers to evolve HCl at elevated temperatures part 3:Conductometric method?alternatives:?part 1:Kongo red method?part 2:pH method?part 4:potentiometric method






