Product category:
Liquid Analysis: Titration, HPLC, IC
News Release from: Metrohm UK | Subject: 859 Titrotherm
Edited by the Processingtalk Editorial
Team on 01 November 2006
Determining free fatty acid content in
olive oil
The acid content of oils - often only present in traces - is a quality criterion and can be determined by thermometric titration using the 859 Titrotherm from Metrohm
The acid content of oils - often only present in traces - is a quality criterion and can be determined by thermometric titration For example, in mineral oils and lubricating oils the total acid number (TAN) is determined and in edible fats and oils the free fatty acids (FFA)
This article was originally published on Processingtalk on 2 Jul 2008 at 8.00am (UK)
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Thermometric titrations to determine the FFA content can be carried out conveniently using the 859 Titrotherm from Metrohm.
This titrator can, of course, also be used for classically indicated titrations.
Dissolve the olive oil in a 1:1 mixture of toluene and 2-propanol and add a small amount of paraformaldehyde to achieve a better endpoint indication.
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Titrate with c(KOH) = 0.1 mol/L in 2-propanol to the endpoint; the reaction is slightly endothermic.
At the endpoint, the excess hydroxyl ions catalyse the hydrolysis of paraformaldehyde.
This strongly endothermic reaction can be seen from the sharp bend in the titration curve.
No sample preparation is necessary.
The Metrohm 859 Titrotherm is a USB-enabled thermometric titrator with one measuring input each for the Thermoprobe and potentiometric sensor - four MSB connections for 800 Dosino and stirrers.
Titrotherm software (English dialogue), Thermoprobe and USB connecting cable for PC is included.
The Metrohm Dosino technology has defined a new standard for precise and simple dosing in volumetric titration.
The dosing unit with its drive motor is mounted on the reagent bottle and thus guarantees maximum precision with minimum space requirements.
The titrator and two burettes require hardly more bench space than a sheet of A5 paper.
The Thermoprobe, a temperature sensor based on semiconductor technology (thermistor), has a short response time of 0.3 s and a high resolution of 10e-5 K.
This makes the Thermoprobe the ideal sensor for thermometric titration, as it can follow any change in temperature quickly and accurately.
The housing made of polypropylene (PP) and epoxy resin provides the sensor with outstanding resistance to many organic solvents and aggressive media.
The clearly laid out Titrotherm software allows adaptation of the screen view to the particular method parameters and thus provides rapid access to important commands or parameters.
The endpoints are determined by calculating the first and second derivatives of the titration curve: by means of additional optimisation parameters, the reproducibility can be improved even further.
For report generation, the titration data can be exported manually or automatically into a freely arranged, method-specific report form. Request a free brochure from Metrohm UK ...
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