Metrohm 794 Basic Titrino - Manual (Page 176)

6.3. User methods
794 Basic Titrino
172
6.3.8 "Sapon.No"
Determination of the saponification number of
edible oils and fats.
Electrode:
6.0229.100 Solvotrode, at measuring input 1.
6.2320.000 Elektrolyte c(TEA-Br) = 0.4 mol/L
in ethylene glycol.
Titrant:
c(HCl) = 0.5 mol/L
Sample:
Weigh in app. 2 g of sample. Add 25 mL
c(KOH) = 0.5 mol/L in ethanol and allow to
boil lightly for at least 30 miutes. Rinse the
content into a beaker and titrate the excess
KOH with HCl.
Determine a blank sample the same way.
Remarks:
Change the result unit e.g. to mg KOH.
Reference:
Metrohm Application Bulletin Nr. 141
– Saponification number in mg KOH per g sample
– Sample size in g
– Molar mass of KOH * normality of titrant
(56.10*0.5)
– Consumption of "blank sample" in mL
'pa
794 Titrino 01102 794.0010
date 2002-01-03 time 09:50 0
DET U Sapon.No
parameters
>titration parameters
meas.pt.density 4
min.incr. 10.0 µl
titr.rate max. ml/min
signal drift 50 mV/min
equilibr.time 26 s
start V: OFF
pause 0 s
meas.input: 1
temperature 25.0 °C
>stop conditions
stop V: abs.
stop V 99.99 ml
stop U OFF mV
stop EP 1
filling rate max. ml/min
>statistics
status: OFF
>evaluation
EPC 5
EP recognition: all
fix EP1 at U OFF mV
pK/HNP: OFF
>preselections
req.ident: OFF
req.smpl size: value
activate pulse: OFF
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'fm
794 Titrino 01102 794.0010
date 2002-01-03 time 09:50 0
DET U Sapon.No
>calculations
Sapon.No=(C30-EP1)*C01/C00;2;mg/g
C00= 1.0
C01= 28.05
C30= 0.0
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