TECATOR Soxtec System, Manual

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14. After t h e solvent has been c o l l e c t e d for 2 - 3 minutes move t h e ...
a i r valve t o t h e "evaporation" p o s i t i o n and c o l l e c t t h e l a s t r e s i d u e o f
t h e solvent in t h e condenser t r a p . (Make sure t h a t t h e a i r pump in t h e
Service Unit is switched on.)
15. Release t h e e x t r a c t i o n cups by r a i s i n g t h e handle on t h e l e f t of t h e
u n i t and remove t h e cups from t h e Extraction Unit using t h e cup holder
and place them in t h e oven (95 - 100°C)for 30 minutes .
16. Gooi t h e cups in a desiccator.Weigh them (WJ and c a l c u l a t e percentage
of f a t according to formula:
W - W
% crude f a t = - ^ - — x 100
w
1
17. After a n a l y s i s r i n s e e x t r a c t i o n cups w i t h ' s u i t a b l e solvent
and wipe dry w i t h soft paper. Empty t h i m b l e s for r e u s e .
VI. RESULTS AND COMMENTS
The 13 samples were analysed using two different times for the
'boiling extraction" and "rinsing" periods respectively. As can
be seen in table 1 the shorter period was in most cases sufficient
to achieve r e l i a b l e r e s u l t s . However, there is a slight tendency
to higher values on some of the samples after the longer extraction
period. Also the relative error was found to be slightly lower
(- 1.36 %) for the longer extraction period (45 min.) than for
.the shorter one (- 1.52 %) . Accordingly the 45 minutes extraction
period should be chosen for this type of samples if maximum r e l i a -
b i l i t y is the ultimate goal.
As can be seen in table 2 the results achieved on the SOXTEC
system agreed quite well with the results from the three
laboratories using classical Soxhlet equipment and 18 hours dura-
tion of extraction in the same solvent. The differences between
1980.01.15 RA/ML AN 2 3 / 8 0