J.P. SELECTA DOSI-FIBER 4 PLAZAS Manual De Instrucciones página 29

MANUAL DE INSTRUCCIONES CODIGO 80055 REV D
J
.P. SELECTA s.a.u.
OCT/2018
Procedure:
1- Weigh and transfer ( precision ±0.1mg) of 1 to 1.5 mg sample into
a porous crucible. The quantity of sample is W
2- Place the crucible into the Dosi-fiber unit.
Hot acid hydrolysis:
3- Ensure that the valves are in «OFF» position.
4- Add to each column 100-150 ml of preheated sulphuric acid and
some drops of foam-suppressor.
5- Open the cooling circuit and turn on the heating elements (power
at 90%)
6- Wait until it boils, reduce the power at 30% leave boiling during
the extraction time (10 min.). For more effective hydrolysis, put
air pump in «soplar» position.
7. To stop heat. Open the vacuum circuit and place the valves in
«ABSORPTION» . Fill with distilled water with the spray in each
column. Repeat this process 3 times.
Hot basic hydrolysis:
8- Repeat the points 3 to 7 by using KOH instead of H
Cold extraction with Acetone
Do not make the cold extraction with acetone in the Dosi-fiber
equipment
9- Prepare the «Kitasatos» flask with the vacuum pump. Place the
crucible in the Kitasatos inlet and add acetone at the same time
that the vacuum circuit is absorbing towards the flask. Repeat it
3 times.
10- Put the samples to dry in an oven at 150ºC during 1 hour.
11 - Leave them to cool inside the vacuum dryer.
12 - Weight the samples with a precision of ±0.1 mg. The weighed
quantity is W
13- Ash crucible samples in a muffle furnace at 500ºC during a mini-
mum of 3 hours.
14- Leave them inside the vacuum dryer to cool. Take note of the
recommendations given for the crucible handling.
15- Weight the crucibles with a precision of ±0.1 mg. The weighed
quantity is W
16- Carry out the following calculation:
Ctra. NII Km 585.1 Abrera 08630 (Barcelona) España
e-mail: jpselecta@sefes.es - http://www.sefes.es/selecta
(It can be modified without notice)
.
1
.
2
Tel (34 3) 770 08 77 Fax (34 3) 770 23 62
Pag.: 29
0.
SO .
2 4