Metrohm 743 Rancimat - Manual (Page 84)

4.6 Determinations ￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭
76 ￭￭￭￭￭￭￭￭ 743 Rancimat
4.6.1 Preparing samples
This section contains information on how to prepare the following sam-
ples:
￭ Pure, clear oils (see page 76)
￭ Non-liquid, pure fats (see page 76)
￭ Samples containing oil and fat (see page 77)
￭ Emulsion fats (see page 79)
Note
Use new reaction vessels and air tubes for each measurement.
Blow the reaction vessel out with nitrogen before use.
Preparing pure, clear oil
Prepare the oil, which is completely pure and clear, as follows:
1 Weigh in the sample
￭ Weigh in 3 g sample material directly in the reaction vessel.
2 Check the filling level
￭ Check whether the quantity of the sample material rises to such
an extent in the reaction vessel that the air tube immerses suffi-
ciently deeply. If this is not the case, add more sample material.
Preparing non-liquid, pure fats
Prepare non-liquid, pure fat as follows:
1 Weigh in the sample
either
￭ Completely liquefy the fat in a water bath or in a drying oven at
a temperature exceeding its melting point by 10 °C.
￭ Then transfer 3 g sample material using preheated pipettes to
the reaction vessel.
or
￭ Weigh in the fat as solid. For this, weigh in 3 g sample mate-
rial directly in the reaction vessel and insert this briefly in the
heated block of the 743 Rancimat, so that the fat melts.