Rancimat Practice vs.ppt - Metrohm
Transcript of Rancimat Practice vs.ppt - Metrohm
Rancimat Practice Rancimat Practice
Principle of Rancimat methodPrinciple of Rancimat method
air inletmeasuring vessel
air inlet
conductivity cellreaction vessel
conductivity cell
sampleabsorption solution
heating block (e.g. 120°C)
(water)
Preparing a determination – reaction vessel
f l bl h f l• Before use vessel was blown out a sharp steam of nitrogen to remove particles
•The reaction vessel cover with the gas inlet tube to be placed immediatelyafter weighing the sample within a few minute.after weighing the sample within a few minute.
•When the sample is placed in the heating block in take approx. 10 -20 Secondbefore the gas flow in the measuring vessel.
S l i li id lSample size – liquid sample
• For liquid samples like q psunflower oil, FAME
• For solid samples that melt like margarine melt like margarine
Instrument cover
Insulating layerMaximumMaximum
A 12 LApprox. 12 mL
Heating blockMinimumMinimum
Approx. 2 mLHeating block Approx. 2 mL
S l i lid lSample size – solid sample
• For solid samples like nuts, PVC
Instrument cover
Insulating layer
Heating blockMaximumMaximum
Appro 0 5 gHeating block Approx. 0.5 g
Air inlet tubeAir inlet tube
With foam barrier Without foam barrierWith foam barrierok
Without foam barrierok not ok
F b i iti iFoam barrier – positioning• Glass fiber reinforced
polypropylene• Solvent resistant
Temperature resistantTemperature resistant120 – 130 °C
MaximumMaximum
Heating block
Preparing a determination – measuring vessel
b i l iAir supplyok
• Absorption solution• 50 – 60 mL deionized
water
Air supplynot ok
atelast for approx. 3 days
• Conductivity < 5 µS/cm
Preparing a determination – method settings
• Important parametersparameters
• Temperature• Temperature• Delta T• Gas flow• Gas flow• Stop criteria
Oxidation stability of natural fats and oils• Standard Rancimat settings• Hardware
• 6.1429.040 Short reaction vessels (150 mm)• 6 2418 100 Gas inlet tubes for oils (148 mm)• 6.2418.100 Gas inlet tubes for oils (148 mm)• 6.1428.100 Polycarbonate measuring vessels• 6.1816.010 Silicone tubingsg
• Method parameters• Temperature: 120°C• Sample amount: 3 g• Air flow: 20 L/h• Water amount: 60 mL• Water amount: 60 mL
• Evaluation• Automatic (2nd derivative)( )• Optional: Manual (tangent method)
Oxidation stability of natural fats and oils• AOCS Method Cd 12b-92 «Oil Stability Index (OSI)»• Method parameters
• Temperature: 100, 110, 120, 130 and 140°C• Sample amount: 2 5 ± 0 2 5 ± 0 2 g• Sample amount: 2.5 ± 0.2 … 5 ± 0.2 g• Air flow: 9 L/h• Water amount: 50 mL
• ISO 6886 «Animal and vegetable fats and oils –d t i ti f id ti t bilit ( l t d determination of oxidation stability (accelerated oxidation test)»
• Method parametersp• Temperature: 100°C• Sample amount: 3 ± 0.01 g• Air flow: 10 L/h• Water amount: 50 mL
Cleaning procedure – step 1Brush with hot water and Rinse with deionized dish washing detergent water
Cleaning procedure – step 2Rinse with deionized Brush with acetone or wateracetone/ethanol or 2-
propanol
Cleaning procedure – step 2 for polycarbonate measuring vessel
• Brush with ethanol or 2-propanol• Do not use acetone!
Cleaning procedure – step 3
• Heat to 80°C for 2 hoursHeat to 80 C for 2 hours
Oxidation stability of FAME (biodiesel)
• EN 14112 «Fatty acid methyl esters (FAME) – Determination of
• oxidation stability (accelerated oxidation test)»y ( )• Hardware
• 6.1429.040 Short reaction vessels (150 mm)• 6.2418.100 Gas inlet tubes for oils (148 mm)6.2418.100 Gas inlet tubes for oils (148 mm)• 6.1428.030 Glass measuring vessels• 6.1839.000 IsoVersinic tubings
• Method parameters• Method parameters• Temperature: 110°C• Sample amount: 3 ± 0.01 g
Air flow: 10 L/h• Air flow: 10 L/h• Water amount: 50 mL
• Evaluationi (2 d d i i )• Automatic (2nd derivative)
• Manual (tangent method)
Oxidation stability of FAME (biodiesel)
• EN 15751 «Fatty acid methyl esters (FAME) fuel and blends• with diesel fuel – Determination of oxidation stability by
l t d id ti t t• accelerated oxidation test»• Hardware
• 6.1429.050 Long reaction vessels (250 mm)• 6.2418.130 Gas inlet tubes for diesel (248 mm)• 6.1428.030 Glass measuring vessels• 6.1839.000 IsoVersinic tubings
• Method parameters• Temperature: 110°C• Sample amount: 7.5 ± 0.1 gp g• Air flow: 10 L/h• Water amount: 60 mL
• EvaluationEvaluation• Automatic (2nd derivative), if possible• Manual (tangent method)
Cleaning procedure – step 1Brush with hot water and Rinse with deionized dish washing detergent water
Cleaning procedure – step 2Rinse with deionized Brush with acetone or wateracetone/ethanol or 2-
propanol
Cleaning procedure – step 3
• Heat to 80°C for 2 hoursHeat to 80 C for 2 hours
Mi llMiscellaneous
•Dust filterDust filter
new still ok replace
•Molecular sieve
new still ok replace
Regenerate weekly in caseof continous use