Tecator soxtec-vetbepaling-manual

* • > * -
Fat determination
by solvent extraction
with Soxtec System
tecator
Sample prepa-
ration(milling,
homogenization
etc.)
weigh sample into
thimble(Wi)
Drying
of samples
nnnnn
H
cm
Fix thimbles into
extraction unit
.
Fix weighed extrac-
tion cups into Ex-
traction Unit.
nnnonn 1
Weigh extraction cups (W2) Add solvent to extraction cups
nnmnn
Boiling extraction with
thimbles in submerged,
boiling position (=^10 min)
- — iV™* *
Final extraction with
thimbles in upper, rinsing
position (=^20 min) followed by sol-
vent evaporation (=^5 min)
Remove extrac-
tion cups
Dry extraction cups Weigh extraction f
cups with extracted /o Tai
fat(W3)
W3—W2 . i n n
—wi—
>•£*„

INTRODUCTION
UNPACKINGAND
CHECKING
INSTALLATION 111:1 CONNECTION
FUNCTION IV:1 1040 EXTRACTION UNIT 8
IV:2 1041 SERVICE UNIT 8
IV:3 EXTRACTION CUPS AND CUP HOLDER 8
IV:4 THIMBLE AND THIMBLE ADAPTERS 10
IV:5 THIMBLE SUPPORT WITH HOLDER AND THIMBLE
STAND 10
IV:6 THIMBLE HANDLER AND TONGS FOR EXTRACTION
CUPS 10
WTM
WLM OPERATION
V:1
V:2
V:3
V:4
V:5
PREPARATION OF SAMPLE
STARTING UP
EXTRACTION
SOLVENT RECOVERY, REMOVAL OF THIMBLES
AND EXTRACTION CUPS
SHUT DOWN
11
11
11
12
12
MAINTENANCE
AND SERVICE Vl:1
Vl:2
Vl:3
Vl:4
Vl:5
Vl:6
Vl:7
SERVICE UNIT 13
WATER PUMP 13
PRESSUREPUMP 13
REPLACEMENT OF HEATING ELEMENT 13
REPLACEMENT OF THERMOSTAT 15
REPLACEMENT OF CONDENSERS 16
REPLACEMENT OF SEALING MEMBRANE 16
Vl:8 REPLACEMENT OF RUBBER SLEEVE BETWEEN
CONDENSER AND EXTRACTION CUP 16
Vl:9. REPLACEMENT OF HOT PLATE 18
VI:10 REPLACEMENT OF FLAT SPRING (HOT PLATE) 18
Vl:11 ADJUSTMENT OF SPACE BETWEEN CONDENSER
AND HOT PLATE 18
TROUBLE-
SHOOTING vil-1
SCHEME Vll:2
FUNCTIONAL TROUBLE-SHOOTING SCHEME
METHOD TROUBLE-SHOOTING SCHEME
19
19
ELECTRICAL
DIAGRAM 20
ACCESSORIES
ANDSPARE
PARTS 21
PROCEDUREAND
APPLICATION
NOTES
MANUAL PART NO 1000-1540

INTRODUCTION
Crude fat is normally defined as what can be extracted by an
appropriate organic solvent — such as diethyl ether. Traditio-
nally, organic solvent fat extractions for quantitative fat de-
terminations are carried out in Soxhlet or related extractors.
Although time consuming and involving the handling of ex-
plosive solvent these methods are universally used thanks to
good accuracy and reproducibility.
The SOXTEC SYSTEM is designed to replace and improve the
traditional organic solvent methods. Still based on the tradi-
tional Soxhlet procedure the patented design of the SOXTEC
SYSTEM makes it possible to carry out a quantitative deter-
mination in only a fraction of the time needed for the traditio-
nal procedures. In addition to the speed of the extraction,
special attention has also been paid to make the SOXTEC
SYSTEM as safe as possible.
The SOXTEC SYSTEM has the flexibility to cope with many
organic solvent extraction demands. This makes the SOXTEC
a convenient and versatile instrument whenever it comes to
quantitative solvent extractions, e.g. in the food, feed and
chemical/pharmaceutical industries as well as in research
and official laboratories.
The samples to be analysed are weighed into thimbles. Dur-
ing the weighing the thimble is connected to the thimble
adapter and placed in the thimble support on the balance. All
handling of the thimbles is done with the thimble handler. No
risk of fat contamination from fingers.
During the extraction in the Extraction Unit the fat is dissolved
in the solvent. After completion of extraction the solvent is
evaporated from the extraction cup into the condenser. AM
fat from the sample is now in the extraction cup.
The Service Unit provides hot water for heating up the hot
plates in the Extraction Unit. The insulated tubing between
the Service and Extraction Units, makes it possible to place
the Service Unit in a separate room. This provides maximum
safety when working with diethyl ether. In the Service Unit
there is also a pump to give air flow into the extraction cups
when evaporating the last residue of solvent.
For specific method information please ask for application
notes.

UNPACKING AND CHECKING
Unpack the SOXTEC SYSTEM and its accessories with care.
Remove all packing material. Use the packing list in this ma-
nual or the one you find packed together with the unit, and
check that you have received all parts. If any part is missing,
contact your Tecator representative.
PACKING LIST
r
r
Part no.
1040-001
1040-002
1040-003
1040-011
1041-011
Quant.
1
1
1
2
1
1
1
3
1
2
1
1
3
3
1
1
1
3
1
1
3
1
2
1
1
2
1
1
2
1
Fig. pos.
A 1
2
3
4
5
6
7
8
9
10
11
12
12
A 13
14
15
16
12
12
A:1 1
2
3
A:2 1
2
3
4
Description
Soxtec System M6 comprising:
1040-011 Extraction Unit
1041-011 Service Unit
1000-1540 Manual
1000-1461 AssemblyKit
1000-1540 Manual
1000-1461 AssemblyKit
1000-1540 Manual
Extraction Unit, complete, comprising:
1000-1462 Extraction Cups (set of 6)
1000-1431 CupHolder
1000-1464 Thimble support (set of 7)
1000-1080 Holder for thimble support
1522-0018 Thimbles(setof25)
1000-1466 Thimble Adapters (set of 6)
1000-1467 Thimble Handler
1529-0007 Tongs for extraction cups
1000-1473 Thimble Stand
1000-1476 Tubing (0 8/11 mm)
1569-0010 Plastic strips
1000-1469 Spare Part Kit A
Service Unit, complete, comprising:
(208—240 V, 50/60 Hz)
1000-1432 Tubing for hot water
1000-1477 Tubing for air
1527-0019 Lubricatingoii
1569-0009 Plastic strips
1000-1468 Spare Part Kit B
Spare Part Kit A comprising:
1000-1420 Sealing membranes (set of 6)
1000-1424 Cylindricseals(setof 6)
1569-0010 Plastic strips (set of 10)
Spare Part Kit B comprising:
1577-0028 Shaft sealing (water pump)
1577-0014 Membrane(pressurepump)
1542-0026 Gasket (set of 4 for
hot water tubing)
1569-0009 Plastic strips (set of 4)

INSTALLATION
Place the units on a laboratory bench. Depending on the sol-
vent you are going to use, the Extraction Unit might be locat-
ed in a fume cupboard separated from the Service Unit.
As an alternative there is a connection on the rear of the Ex-
traction Unit which can be connected via fiexibie tubing to a
ventilation fan. The Extraction Unit must be placed close to a
cold water tap and drainage.
111:1. CONNECTION
Connect the PVC-tubing (0 8/11 mm) for cold water according
tofig. B.
Connect the insulated rubber tubing for hot water according
to fig. B. Make sure that the rubber seals are on place. (Fig. C)
It is enough to fasten the connection by hand.
The Service Unit must be placed close to a wall socket. Never
connect it without water in the tank. Connect the hot water
tubing from the Extraction Unit and the PVC-tubing for air.
Seefig. B.
If necessary the Extraction Unit can be placed further away
from the Service Unit (standard length of the hot water tubing
is 3 m). For this purpose the 1000-1460 extension kit should
beused.
If you are going to connect an additional Extraction Unit use
the 1000-1461 assembly kit.
r
r
Fig.B
1. Cold water inlet for con-
densers (water flow 1—2 1/
min.)
2. Water outlet from conden-
sers
Hot water connections: 7 con-
nected to 3 and 8 connected
to4
Air tubing connection: 6 con-
nected to 5
9. Electrical cable
1 2
6 o
70
8 O O9
3
O
4
O O
5
o

Fig.C
Fig.D
When the Extraction Unit and Service Unit are connected, fill
distilled (or deionized) water into the tank in the Service Unit
(Fig. D). As soon as the element in the tank is covered with
water (ca 2 I), plug into the wall socket (208/240 V, 50/60 Hz, 10
A) and switch on "MAINS". Open the valve "HEATING" on
the Extraction Unit to get rid of air in the hotplates and tub-
ing. Fill more water into the tank. The water level should be a
few cm below the edge of the tank. (ca 4 I with one Extraction
Unit and Standard tubings).
Fill about 50 ml of the lubricant oil (1527-0019) into the tank
(this is in order to avoid unnecessary wear of the pump).
The thermostat is adjusted to about 90°C when the equip-
ment is shipped to you. If you want a lower temperature, use
a small screw driver and turn the screw on the thermostat
counter clock-wise. Fig. E. (Check temperature with a thermo-
meter in the tank.)
Normal heating-up time from room temperature to 90°C is
about 15 minutes (220 V). Switch on "AIR" to check that the
air pump is working.
NOTE: Always run a blank with the new equipment to get rid
of deposits in the condensers.
Fig.E

FUNCTION r
The SOXTEC SYSTEM com-
prises:
— 1040 Extraction Unit
— 1041 Service Unit
— Extraction Cups
— Cup Holders
— Tongsfor extraction cups
— Thimble Supports
— Hoider for thimble sup-
ports
— Thimbles
— Thimble Adapters
— Thimble Handler
— Thimble Stands
— Tubing for hot water and
air
IV:1. 1040 EXTRACTION UNIT (Fig. F)
In the Extraction Unit the fat extraction is done in two steps.
First the thimble with sample is immersed in the boiling sol-
vent. Most of the fat now dissolves in the solvent. In the sec-
ond stage the thimble is raised above the solvent surface and
the fat residue in the sample is washed out by the solvent
dropping from the condenser.
After the extraction the knob above the condenser is turned
clockwise. This will close the outlet for condensing solvent.
After some minutes most of the solvent is collected in the
condenser. The last residue of solvent is evaporated when
the air valve is opened.
IV:2. 1041 SERVICE UNIT
The Service Unit provides hot water to the Extraction Unit
from a built in tank. The thermostat in the tank is adjustable
from the outside of the Service Unit (Fig. E). The hot water is
pumped from the Service Unit to the hot plates in the Extrac-
tion Unit. The pump can work even if the valve on the Extrac-
tion Unit isclosed.
In the Service Unit there is also a pump to give the air flow for
evaporating the solvent.
IV:3. EXTRACTION CUPS AND CUP HOLDER
With the cup hoider all six extraction cups are carried with
one hand when inserting and removing them in the Extrac-
tion Unit, or when moving them to the balance. The extraction
cups are made of aluminium. Never place the extraction cups
on a dirty surface during analysis. This might alter the tare
weight. Before use check that the bottom surface of the cups
is clean, otherwise the heat transfer from the hot platos
might be disturbed and result in longer boiling start time.
8
Explanation of symbols in fi-
gure F
1. Recoveryknob
2. Condenser
3. Extraction mode knob
4. Sliderail
5. Extraction Cup
6. Cup Hoider
7. Hotplate
8. Air valve
9. Hot water valve
10. Fastening mechanism
11. Lever for fastening
mechanism

IV:4. THIMBLE AND THIMBLE ADAPTERS
Standard size of thimbles is 0 26 mm and length 60 mm.
Thimble adapters for other thimbles are also available (0 22
mm, length 50 mm; part no: 1000-1486).
IV:5. THIMBLE SUPPORT WITH HOLDER AND THIMBLE
STAND
Six thimble supports are fastened in the holder. (Fig. G) This
combination is used to fix the thimbles (in thimble adapters)
to the magnets in the condensers of the Extraction Unit. One
thimble support is used on the balance when weighing
sample into the thimble.
The thimbles are placed in the thimble stand during drying.
IV:6. THIMBLE HANDLER AND TONGS FOR EXTRACTION
CUPS
To avoid finger prints on thimbles, the thimble handler is
used when moving a thimble from the balance to the thimble
stand or the thimble support. (Fig. H) For the same reason the
pair of tongs is used when placing extraction cups in a drying
oven oradesiccator.
rFig.G
fI
L
Fig.H
10

OPERATION
V:1. PREPARATION OF SAMPLE
Samples must be ground or homogenized before weighed in-
to the thimbles. Some types of samples e.g. meat, should be
mixed with sand or asbestos. Follow the same procedure as
for traditional Soxhlet.
's.
Fig.I
m
fiSSüï
Fig.J
V:2. STARTING UP
A) Check water level in the Service Unit (should be a few cms
below the edge of the tank).
b) Press MAINS button (switch-lamp should light).
c) Open the left valve on the Extraction Unit to HEATING.
This will allow the water to circulate. Normal heating-up
time (to 90°C) is about 15 minutes.
d) Open cold water tap for the reflux condensers. The flow
rate should be adjusted to 1—2 l/min to prevent loss of
solvent from the tops of the condensers.
V:3. EXTRACTION
a) Attach thimble to adapter (Fig. I).
b) Weigh sample into thimble (the thimble is placed in the
support on the balance).
c) Move thimble to the thimble stand. Use thimble handler.
The thimble is released when the handler is pressed. Dry in
oven.
d) After drying, put defatted cotton plug above the sample
and place thimbles in thimble support (in holder). Use
thimble handler. (Fig. J).
e) Insert the thimbles into the condensers. Raise the holder
so that the support enters into the condensers. Note, the
six knobs (extraction mode) should be in the rinsing posi-
tion (Fig. K).
f) Move each extraction mode knob up to boiling position.
The magnet will now fasten the thimble adapter. Return
the knob to rinsing position, the thimble will now hang
just under the membrane in the condenser.
g) Take out the thimble supports.
h) Insert six extraction cups, tared with boiling chips and
loaded with about 50 ml of the solvent to be used (see pa-
ra V.4.g). Use the cup holder. Lower the handle ensuring
that the safety latch engages. The cups are now tighte-
ned to the condensers (Fig. L).
i) Move the extraction mode knobs to "boiling". The thimb-
les will now be immersed in the solvent.
j) Open the valve "HEATING" and boil with the thimbles im-
mersed. (Time depending on sample and solvent type.)
Make sure that the knobs above the condensers are in up-
11

per position (full counter clock-wise) so that the conden-
sing solvent can reflux back into the cups (Fig. M).
k) Move the extraction mode knobs to RINSING. The thimb-
les will now hang above the solvent surface and any fat
residues will be rinsed out.
f
V:4. SOLVENT RECOVERY, REMOVAL OF THIMBLES AND
EXTRACTION CUPS
a) After the rinsing period turn the knob above the conden-
ser clock-wise until the tube enters a few mm through the
membrane. The tube will tighten and prevent the conden-
sing solvent flowing back into the extraction cup.
NOTE: If the tube is moved too f ar down it will stick to the
membrane when all the solvent is evaporated.
b) When almost all solvent is collected in the condenser
(about 4—5 minutes for 50 ml diethylether), Press AIR but-
ton on the Service Unit and open the valve EVAPORATION
on the Extraction Unit. The last residues of solvent will
now be collected in the condensers.
NOTE: If the Service Unit is located in another room the
AIR pump can be on all day.
If the EVAPORATION air flow is used earlier the time for
evaporating the solvent will be shorter but some solvent
will be lost.
c) Close the HEATING and EVAPORATION valves. Release
the extraction cups with the safety hook (Fig. N). Lift out
all six cups with the cup holder.
d) Place thimble supports (in holder) onto the hot plates and
lower the handle so the supports enter the condensers.
e) Move extraction mode knobs so that the thimbles enter
the supports.
f) Release handle, follow the upward movement with the
support holder. Bend the support holder (Fig. O) and re-
move the thimbles.
g) If another extraction is to be performed immediately, in-
sert a new batch of thimbles and cups (para V.3, e—h)
and open the recovery valves by tuming the knobs above
the condensers counter clockwise.
NOTE: If diethylether is used make it a rule to empty the
recovered solvent into a cup and check for peroxides be-
fore reusirfg.
NOTE: If recovered volume is too small, add more solvent
with a syringe in the small hole in the white ring on the
top of the condenser (50 ml leve! is just below lower edge
of front panel) (Fig. P).
V:5. SHUTDOWN
a) Turn off MAl NS.
b) Turn off cold water tap.
c) Check that all condensers are emptied of solvent. Leave
the knobs above the condensers in upper position (coun-
ter clock-wise).
r
i
Fig.M
Fig.N
12

MAINTENANCE AND SERVICE
Vl:1. SERVICE UNIT (general for all work inside the Service
Unit)
a) Take out electrical plug from wall socket.
b) Unscrew the four screws (two on each long side) and lift
up the cover (Fig. Q and R, pos. 2).
Vl:2. WATER PUMP
If the pump leaks, the O-ring and shaft seal can be replaced
asfollows:
a) Empty the watertank.
b) Loosen the screws on the two tubing clamps. (Fig. R, pos.
1)-
c) Unscrew the nuts holding the pump motor. (Fig. R, pos. 3).
d) Take avvay the pump.
e) Loosen the eight screws holding the pump housing. (Fig.
R, pos. 18).
f) Remove front part of the pump housing. (Fig. S, pos. 1).
g) Remove the old O-ring. (Fig. S, pos. 2).
h) Remove the pump rotor (Fig. S, pos. 3) by loosening the
centre screw (note screw clock-wise) (Fig. S, pos. 4).
i) Loosen the four screws holding the rear part of the pump
housing and remove it (Fig. S, pos. 5).
j) Unscrew the three screws holding the shaft seal and re-
place the seal (Fig. S, pos. 6, 7).
k) Assemble the pump housing with a new O-ring.
Fig.Q
Vl:3. PRESSURE PUMP
1) To increase the air flow screw clock-wise on the plastic
screw on the side of the air pump (Fig. R, pos. 8).
2) Replacement of membrane:
a) Unscrew the nut holding the pump and lift it out.
b) Unscrew the screw for membrane (Fig. R, pos. 10).
c) Remove the rubber base of the pump and change mem-
brane (Fig. R, pos. 9).
d) Replace the base and fix the pump into the unit.
Vl:4. REPLACEMENT OF HEATING ELEMENT
a) Empty the water tank.
b) Unscrew the nut holding the tank (Fig. R, pos. 11).
c) Loosen the screws on the two tubing clamps on the tank
(Fig. R, pos. 12).
d) Loosen the nut on the thermostat body (Fig. R, pos. 13).
e) Lift out the tank, carefully remove the thermostat body
from the tank.
13

Explanation of symbols in
Fig.R
1. Tubing clampscrews
2. Screws for cover
3. Nuts holding motor
4. Capacitor
5. Thermostat
6. Thermostat body
7. Air pump
8. Plastic screw for adjust-
ting of airflow
9. Air pump membrane
10. Screw to be unscrewed
before changing mem-
brane
11. Nut holding watertank
12. Screws to be loosened
before removing water
tank
13. Nut for thermostat body
14. Nutfor heating element
15. Heating element
16. Cableconnection on
thermostat
17. Nut for thermostat
18. Screw holding water
pump housing
19. Watertank
f) Remove the cable connections.
g) Remove the nuts holding the element (Fig. R, pos. 14).
h) Replace the element (Fig. R, pos. 15). Make sure that the
sealings are inside the tank.
Vl:5. REPLACEMENT OF THERMOSTAT
a) Follow the procedure Vl:4, a—e.
b)
c)
d)
Disconnect the two cables on the thermostat. (Fig. R, pos.
16).
Remove the nut on the thermostat. (Fig. R, pos. 17).
Replace the thermostat and reassemble the Service Unit.
Fig.S
2.
3.
4.
5.
6.
7.
Explanation of symbols
1. Front part of pump hou-
sing
O-ring
Pump rotor
Centre screw to pump ro-
tor
Screw holding rear part of
pump housing
Screw holding the shaft
seal
Shaft seal
15

Vl:6. REPLACEMENT OF CONDENSER (complete)
a) Raise all extraction mode knobs to middle position in the
orange area.
b) Unscrew the three screws holding the front panel and
gently pull the panel down. The six slides will come out
from their plastic rails (Fig. T, pos. 1).
c) Remove the two nuts from the top plate (Fig. T, pos. 2).
d) Lift away the top plate.
e) Carefully loosen the glass condenser and pull it up until
it is clear of the seal (the condenser is pressed down into
the rubber sleeve).
f) Disconnect the PVC-tubing.
g) Replace the condenser (Wet the glass before putting it in-
to the rubber sleeve).
h) Assemble and run a blank to get rid of deposits.
Vl:7. REPLACEMENT OF SEALING MEMBRANE
a) Follow the procedure for replacement of condenser (Vl:6,
a—d).
b) Lift away the knob on the recovery tube. The tube must be
in its upper position (Fig. U, pos. 1).
c) Lift away the upper condenser holder and ease it over the
curved tube.
d) Carefully loosen the condenser (see Vl:6 e). Let the con-
denser hang on its PVC-tubings.
e) Slide the flexible wire into the curved tube so that the
magnet is free below the condenser (Fig. U, pos. 3,5).
f) Pull out the magnet with rod and flexible wire.
g) Lift up recovery tube through the condenser (Fig. U, pos.
4).
h) Take out the old membrane. To eliminate the risk of break-
ing the glass condenser, the best way is to cut the mem-
brane with a knife or a scalpel.
i) Put in the new membrane. Wet it with water first. Press it
in as far as possible using fingers. For the last part use a
spatula. The membrane must fit into the groove in the
condenser.
j) Assemble the condenser and put it back in its place. Run
a blank to get rid of deposits.
Vl:8. REPLACEMENT OF RUBBER SLEEVE BETWEEN CON-
DENSER AND EXTRACTION CUP
r
a)
b)
c)
d)
16
Loosen the condenser. Follow the procedure for replace-
ment of condenser (Vl:6, a—e). Let the condenser hang in
thePVCtubings(Fig.V).
Pull down the old sleeve.
Withdraw the teflon tubing.
Ease off the guide ring from the rubber sleeve and put it
on the new sleeve. Make sure the hole in the ring fits over
the hole in the rubber sleeve (Fig. W).
r
Explanations to symbols in
Fig.T
1. Screws holding the front
panel.
2. Nuts holding top plate.
Fig.T
S B B P ^ '•"

Explanation of symbols
Knob on recovery rod
Upper condenser holder
Flexiblewire
Recovery tube
Curved tube
Magnetwith holding
mechanism
Sealing membrane
Plastic rail forslide
Slide
Extraction mode Knob.
L_ 17

e) Put the teflon tubing into the hole, so it enters about 1 mm
inside the rubber sleeve. It might be necessary to use a
pin to clear the hole in the rubber part.
f) Put the new sleeve on place and replace the condenser.
Run a blank to get rid of deposits.
Vl:9. REPLACEMENT OF HOT PLATE (Fig. X)
If distilled or deionized water is used in the Service Unit there
will be no problems with the hotplates. If for some reason tap
water is used, deposits inside the hot plate can disturb or
close the water flow.
r
Fig.X
Fig.X
1. Hot plate
2. Snap ring
a) Empty the water tank and disconnect the hot water tubing Explanation to symbols in
from the Extraction Unit.
b) Turn the apparatus so it is resting on the rear plate.
c) Remove the tubing from the hotplate.
d) Remove the snap ring. (Spring loaded).
e) Lift up the hot plate.
f) Put in the new hot plate. Make sure that the flat spring is
in place. Replace the snap ring and connect the tubing
again.
VI:10. REPLACEMENT OF FLAT SPRING (HOT PLATE)
a) Remove the hot plate (according to Vl:9, a—e).
b) Replace the flat spring.
Vl:11. ADJUSTMENT OF SPACE BETWEEN CONDENSER
AND HOT PLATE
Inside the lower part of the unit there are two adjusting
screws (Fig. Y, pos. 1). Loosen the nuts and adjust the space
so that the extraction cups are firmly fixed.
Fig.Y
Explanation of symbols in
Fig.Y
1. Adjusting screws
18

TROUBLE-SHOOTING SCHEME
Vll:1. FUNCTIONALTROUBLESHOOTING SCHEME
Fault
A. The waterpump does not
start
B. The hotplates do not
heat up
C. Poor reflux of solvent
D. Solvent leakes out
F. Hotwater leakage
Probable Cause
1. Nocurrentto the pump
1. Too low temperature in
tank
2.
1.
2.
3.
4.
1.
2.
E. Too long evaporation time 1.
2.
3.
4.
1.
2.
3.
Heating valveclosed
Too low water flow in the
condensers
Too low temperature on
the hotplates
Extraction Cup contamina-
ted on bottom surface
Recovery Valve closed
Extraction Cup incorrectly
placed
Rubber Sleeve between
condenserand extraction
cup isdamaged
Too low temperature on
the hotplates
Extraction Cup contami-
nated on bottom surface
Poor ornoairflow
Sealing membrane dama-
ged
Unsatisfactory tightening
of theconnections
Rubber seal in the connec-
tion isdamaged
Shaft seal on the water
pump isdamaged
Corrective Measure
Connect the cable. Switch on
Mains
Screw the thermostat clockwise
(Check temperature with a ther-
mometer in the tank)
Open the Heating valve
Increase the water flow
Adjust thermostat in watertank
Clean the Extraction Cup
Open Recovery Valve. Turn
counter clockwise
Place Cups on center of the hot
plates
Replace the rubber sleeve
Adjust thermostate in water-
tank
Clean the Extraction Cup
Check that evaporation valve is
open and that the PVC-tubing
between Service and Extraction
Unit is not blocked. Check the
pressure pump according to
para Vl:3
Replace membrane according
topara Vl:7
Fasten the connections
Replace the seal
Replace the shaft seal accord-
ing topara Vl:2
Vll:2. METHOD TROUBLE SHOOTING SCHEME
Fault
A. Too great deviation bet-
ween results from tests on
the same sample
B. Solvent (with fat) frothing
up on the thimble during
rinsing or evaporation
Probable Cause
1. Too coarse structure of
the sample
2. Unsatisfactory mixing of
sample prior to weighing
3. Unsatisfactory weighing in
of sample or cups
4. Too short extraction time
5. Poor reflux
1. Too high fat content
2. Too high temperature
on the hot plate
Corrective Measure
Grind or homogenize to a finer
structure
Check the mixing procedure
Check the weighing procedure
Check the extraction time
See section C under Vll:1
Weigh in less sample
Adjust the thermostat in the
watertank
19

ELECTRICAL DIAGRAM
r
1041 Service Unit
r
200—240V
MAIN
SWITCH
AIR
SWITCH
THERMO
STAT
AIRPUMP
WATERPUMP
HEATING
ELEMENT
20

ACCESSORIES AND SPARE PARTS
IX:1. ACCESSORIES
(for one piece) Order no
Extraction cups (set of 6) 1000-1462
Cup Holder 1000-1431
Tongs for extraction cups 1529-0007
Thimbles0 26mm(setof25) 1522-0018
Thimbles0 22mm(setof25) 1522-0009
Thimble support (set of 7) 1000-1464
Thimble adapters (set of 6, 0 26 mm) 1000-1466
Thimble adapters (set of 6, 0 22 mm) 1000-1486
Holder for thimble support 1000-1080
Thimble Handler 1000-1467
Extension kit for distribution of hot water and air,
comprimising: 1000-1460
2 ea tubing for distribution of hot water (L = 3 m)
complete with connections
1 ea tubing for distribution of air (L = 3 m
0 4/6 mm) complete with connections
Assembly kit for additional Extraction unit,
comprising: 1000-1461
2 ea Tubing for distribution of hot water
(L = 0.75m)inclT-piececonnection
1 ea Tubing for distribution of air
(L = 1 m, 0 4/6 mm)
Lubricating oil (for Service Unit) 1527-0019
L-,
L
IX:2. SPARE PARTS
For extraction Unit:
Condenser, complete, with recovery and
thimble mechanism 1000-1445
Condenser, glass 1000-1419
Sealing membrane in condenser 1000-1420
Knob for recovery rod 1000-1423
Cylindric seal between condenserand extrac-
tion cup 1000-1424
Valve for hot water and air 1584-0006
Tubing for cold water, 0 8/11 mm, per m 1582-0004
Tubing for hot water, 0 6/12 mm, per m 1582-0023
Tubing for air, 0 4/6 mm, perm 1582-0005
Hot plate, complete 1000-1444
Flat spring for hot plate 1000-1404
Strips, big 1569-0010
Timer 1562-0017
For Service Unit:
Water Pump, complete 1577-0024
Shaft sealing to water pump 1577-0028
O-ring to water pump 1577-0027
p.t.o.
21

Air pump 1577-0008
Air pump membrane 1577-0014
Heating element 1000-1403
Thermostat 1579-0007
Strips, smalI 1569-0009
Switch red 1563-0001
Switch yellow 1563-0006
Pump body to water pump 1577-0029
tecator

J
1980.01.15 RA/ML AN 23/80
RAPID DETERMINATION OF CRUDE FAT
IN FEED STUFFS
BY USING THE SOXTEC SYSTEM
(DIETHYLETHER)
I. INTRODUCTION
The classical Soxhlet extraction with diethylether has for a long time been
used for the determination of crude fat in feed stuffs. Bowever, the method
is tedious and labour intensive. The SOXTEC SYSTEM has been developed to
eliminate the drawbacks of the original procedure. A number of determinations
have been perforraed to evaluate the SOXTEC systera in comparison with the
classical Soxhlet method.
As most fats and waxes are more soluble in hot solvents than in cold ones,
the sample in the SOXTEC EXTRACTION UNIT is first submerged in the boiling
solvent after which the remaining fat is rinsed out by the refluxing solvent
with the sample raised above the solvent surface.

This application note describes crude fat determination on f eed stuffs and
raw materials using diethylether as solvent.
II. MATERIALS
The test samples used in this study included pig feed (3), cattle feed (3),
poultry feed (2), coconut oil meal (1), cotton seed meal (1), oats (1),
fish meal (1) and corn (1). The moisture content of the samples was in the
range of 8 - 12 per cent and the samples were ground on a Cemotec mill set
to pos. 1.
III. EQÜIPMENT
1. Cemotec Mill (1090 - 001) or a Cyclotec sample mill (1900 - 0300).
It should be kept in mind that the Cyclotec mill will dry the samples
to some extent and that the results must be adjusted accordingly.
2. Analytical balance with an accuracy - 0.1 mg.
3. Soxtec System M6 (1040 - 001) complete with accessories.
4. Thimbles 26 x 60 mm (1522 - 0018).
5. Graduated cylinder 50 ml.
6. Heating oven (95 - 100°C).
7. Desiccator.
IV. CHEMICALS
1. Diethylether (anhydrous) f ree from solids, and peroxides. Store in
dark place over metallic sodium. Check regularly for peroxides.
Procedure for peroxide test: 2 - 3 ml diethylether is shaken with
1 ml of a dichromate solution (1 % K,Cr9O7 in 0.1 N sulphuric acid).
If it turns blue the ether contains peroxides and should be discarded.
1980.01.15 RA/ML AN 23/80

C A U T I O N
DIETHYLETHER IS HIGHLY INFLAMMABLE AND SHOULD ONLY BE USED BY QUALIFIED
LABORATORY TECHNICIANS WHO HAVE BEEN PROPERLY TRAINED IN THE SAFETY ASPECTS
OF ITS USE. PIACE THE SERVICE UNIT IN A SUITABLE PLACE WELL APART FRCM THE
PLACE WHERE DIETHYLETHER IS HANDLED. MAKE SURE THAT VENTILATION IS ADEQUATE
AND THAT THE SOLVENT IS FREE FROM PEROXIDES.
2. Cotton wool (defatted).
3. Boiling chips (glass balls 0•*3 mm).
V. PROCEDURE
1. Turn on the Service unit in order to heat water to the working
temperature (75 C).
2. Fix thimble into thimble adaptor and place it in the thimble
stand. Put sorae cotton wool in the bottorn of the thimble. Always
use defatted thimbles and cotton wool. Never handje them with
your bare hands.
3. Place a thimble support on the balance. Use the thimble handler
to transfer thimble (fixed to adaptor) from the stand to the
support. Tare support plus thimble and weigh in the ground and
well mixed sample. Note the weight (W1) .
Use about 3 g if fat content < 10 %
use about 2 g if fat content > 10 %.
Put a plug of cotton wool on top of the sample.
4. Dry the thimbles with sample in an oven (95 - 100 C)
for two hours.
1980.01.15 RA/ML AN 23/80

5. Weigh clean and predried extraction cups with some boiling chips (W2).
Never touch the clean extraction cups with bare hands!
6. Transfer the dried thimbles with the thimble handler into the thimble
supports (6 pcs fixed to its holder).
7. Insert all six thimbles into the Extraction Unit and make sure they are
all properly held by the magnets. Place all thimbles in the "rinsing"
position and then remove the holder with the supports.
8. Put about 50 ml diethylether into the preweighed extraction cups
(6 pcs placed in a cup holder) .
9. Insert the extraction cups with the holder into the Extraction Unit.
Make sure they are placed in the centre of the hot plates and lock them
in place by lowering the handle on the left of the Extraction Unit.
The cups will then tighten against the seals on the condensers.
10. First switch on cold water through the condensers and then switch on
the "heating" valve. Preheated water (^75 C) from the Service Unit
will then flow through the hot plates and heat the solvent to the
boiling point.
11. Move the thimbles to the "boiling" position and make sure that there
is good reflux from the condensers. Turn the recovery knob to f uil,
counter clock wise (upper) position.
12. After 10 or 15 minutes boiling, raise the thimbles above the ether
surf ace by moving the knobs on the panel to the "rinsing" position.
13. When the rinsing period is over turn the recovery knob clockwise
(until the tube enters a few mm through the membrane) and collect
the solvent in the "condenser trap".
1980.01.15 RA/ML AN 23/80

14. After the solvent has been collected for 2 - 3 minutes move the ...
air valve to the "evaporation" position and collect the last residue of
the solvent in the condenser trap. (Make sure that the air pump in the
Service Unit is switched on.)
15. Release the extraction cups by raising the handle on the left of the
unit and remove the cups from the Extraction Unit using the cup holder
and place them in the oven (95 - 100°C)for 30 minutes .
16. Gooi the cups in a desiccator.Weigh them (WJ and calculate percentage
of fat according to formula:
W - W
% crude fat = - ^ - — x 100
w1
17. After analysis rinse extraction cups with'suitable solvent
and wipe dry with soft paper. Empty thimbles for reuse.
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 reliable results. 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 relia-
bility 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 23/80

the three Soxhlet laboratories, of which two (A and C) are official
laboratories and the third (B) is a well reputed large laboratory in a
fcooperative organization, emphasxze the difficulties in gettxng comparable
xesults using the Soxhlet method. There is no doubt, hpwever, that there is
a remarkable good correlation between all the laboratories involved in the
tests. If laboratory A, one of the official laboratories, is used as a
reference, correlation coefficients and confidence intervals can be
calculated according to table 3.
In some recent studies it has been demonstrated that the particle
size does have a significant effect on the extractability of the
fat. Both the Soxhlet and the SOXTEC methods show the same r e s u l t s .
In these studies it was also shown that the total content of
extractable matter is generally higher with the SOXTEC system
than with the Soxhlet method. The differences between the two
methods are of course dependent on the solvent used,' the particle
size and the duration of the extraction. For ultimate accuracy
the analysts are therefore requested to check the results achieved
on the SOXTEC system with official results on the same samples.
Based on such data the extraction time in the SOXTEC system can
be adjusted to get directly comparable results or a small correc-
tion factor can be applied. The l a t t e r alternative is to be
recommended, when speed is of importance.
The influence of different laboratory technicians on the results was
tested in a small trial, the results of which are shown in table 4.
No differences were found.
Some samples may cause frothing in the extraction cups due to their fat
composition. To avoid this the temperature of the circulating water in
the Service Unit should not exceed 75 C, (usingdiethylether) . Another
cause of frothing is a too high fat concentration in the solvent. Therefore
we recommend lower sample weight if the fat content is high.
With low density samples such as cotton seed meal, the weight might have
to be reduced in order to prevent over filling of the thimble. The sample
in the thimble should not reach above the lower edge of the thimble adaptor.
1980.01.15 RA/ML m 23/8Q

TABLE 1
Comparison between two different extraction times on SOXTEC
SAMPLE
Pigfeed
Pigfeed
Pigfeed
Cattle
Cattle
Cattle
Poultry
Poultry
Coconut
Cotton
Oats
I
II
III
feedI
feed II
feed III
feed I
feed II
oil meal
oil meal
Fish meal
Corn
-
10 +
2.26
3.50
2.32
3.23
5.82
5.84
2.34
4.29
15.88
8.96
3.66
11.25
1.98
5 0 X
20 minutes
2.25
3.39
2.31
3.39
5.83
5.99
2.35
4.36
16.21
8.85
3.68
11.52
1.98
X
2.26
3.45
2.32
3.31
5.83
5.92
2.35
4.33
16.05
8.91
3.67
11.39
1.98
T E
15 +
2.24
3.41
2.34
3.30
5.82
6.05
2.41
4.36
16.17
9.10
3.77
11.42
2.11
C
30 minutes
2.21
3.46
2.36
3.29
5.76
6.14
2.36
4.31
16.39
8.94
3.84
11.43
2.05
X
2.23
3.44
2.35
3.30
5.79
6.10
2.39
4.34
16.28
9.02
3.81
11.43
2.08
TABLE 2
Comparison between the SOXTEC and SOXHLET results from some different
laboratories.
SAMPLE
Pig feed I
Pig feed II
Pig feed III
Cattle feed I
Cattle feed II
Cattle feed III
Poultry feed I
Poultry feed II
Coconut oil meal
Cotton oil meal
Oats
Fish meal
Corn
rel. error %
SOXTEC
2.23
3.44
2.35
3.30
5.79
6.10
2.39
4.34
16.28-
9.02
3.81
11.43
2.08
1.36
S O X H L E T
LAB A
2.26
3.39
2.60
3.45
5.78
6.10
2.49
4.34
16.58
9.11
3.93
11.51
2.12
1.47
LAB B
2.39
3.74
2.86
3.47
6.00
6.16
2.79
4.64
16.83
9.26
4.20
11.75
2.13
1.69
LAB C
2.44
3.80
2.67
3.82
5.89
6.16
2.64
4.46
16.77
8.95
4.35
11.66
2.19
1.31
1980.01.15 RA/ML AN23/80

TABLE 3
Linear regression with 9 5 % (t=2.20) confidence interval
at four fat levels (Gomparison against laboratory A)
F
Fat level S 0 X T E C
10+20 min 15+30 min
S O X H L E T
Lab B Lab C
2 %
5 %
10 %
15 %
1.8 - 2.0
4.8 - 5.0
9.6 - 9.!
14.6 -14.9
1.9 - 2.0
4.9 - 5.0
9.8 -10.0
14.7 -15.0
2.1 - 2.3
5.1 - 5.3
10.1 -10.3
15.0 -15.4
2.1 - 2.3
5.1 - 5.3
10.0 -10.3
14.8 -15.3
correl.
coeff.
0.9995 0.9998 0.9997 0.9993
TABLE 4
Three samples analysed by two laboratory technicians on
the SOXTEC SYSTEM
Duration
of extrac.
Lab. tech.
Sample I
Sample II
Sample III
30 min.
a
2.36 2.36
4.33 4.29
2.37 2.36
b
2.34 2.35
4.26 4.29
2.32 2.31
• 45 min.
a
2.39 2.33
4.33 4.35
2.38 2.37
b
2.36 2.35
4.31 4.36
2.36 2.34
1980.01.15 RA/ML AN 23/80

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