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).
Determination of the FFA content.
Thermometric titrations 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.
Titrate with c(KOH) = 0.1mol/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 859 Titrotherm is a USB-enabled thermometric titrator with one measuring input each for 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.
Dosino technology - precise and simple dosing Metrohm's Dosino technology has defined a new standard for 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 burets require hardly more bench space than a sheet of DIN A5 paper.
Thermoprobe - quick, precise and robust Thermoprobe, a temperature sensor based on semiconductor technology (thermistor), has a short response time of 0.3s and a high resolution of 10-5K.
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 software - everything at a glance, everything under control 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 optimization 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.
