4.3
Hydrolysis
1.
Weigh the samples with a precision of
1000
±
2 mg and transfer them to the sample
tubes.
2.
Add 1-2 g of celite and 100-120 ml of the
acid solution to each sample tube. The
level of the acid solution must be over
the top of the cover of the heaters.
3.
Insert the tubes into position in the
1047 Hydrolyzing Unit (Fig. 4). Lower the
suction tubes to the fume exhaust
position by pulling the handle upwards
(Fig. 5). The teflonpart should rest on
the top of the sample tubes and the
suction tubes should be about one
centimeter down in the sample tubes.
4.
Place the glass thimbles into the thimble
supports (Fig. 6) and insert them into
the Hydrolyzing Unit(Fig. 7).
Note: If pre-extraction according to section 4.2 has been
carried out, check that the thimbles are used for the same
samples as in pre-extraction.
5.
Start the water aspirator pump for the
fume exhaust system. Open vacuum valves
(Fig. 7) under each thimble. Adjust
during boiling for low fume exhaust.
6.
Turn on the heater to maximum effect and
place the reflector in front of the
sample tubes. When the solution starts
boiling, adjust to a gently boiling speed
with the heater control (Fig. 8).
7.
At the end of the hydrolysing period,
turn off the heater and remove the
reflector.
8.
Open the cold water tap for the
condensers (approximately 2 l/m).
9.
Pull down the suction tube handle to
pos. 1 (Fig. 5). Dilute the acid solution
in each tube with some 100 ml of 20-25
°
C
distilled water. Close the vacuum valve
(Fig. 7) under each thimble.
10. Lower the suction tubes to pos. 2
(Fig. 5). Open the vacuum valve (Fig. 7)
under one thimble and suck up the sample
solution and as much as possible of the
solid particles in the solution. Close
the valve and repeat in the same way with
the rest of the tubes.
1047
Soxtec
System
Hydrolyzing
Unit,
User
M
anual,
R
ev.
2.2,
Part
no
1000
3315,
Foss
Tecator
AB,
Sweden
8
1047014A
2
1
Fig. 5
Pull the handle up (to pos 2) to
lower the suction tubes.
1047015A
Fig. 6
Use gloves when handling thimbles
to minimize contamination.
1047016A
Fig. 7
Turn the knob to open/close the
vacuum valve.
