BUCHI SpeedDigester K-436 - Manual (Page 35)

6 Operation
35 K-425 / K-436 Operation Manual, Version A
6 .4 Performing a peroxide digestion process
This section is divided into two consecutive sub-sections (6.4.1 and 6.4.2) and follow-up actions in
section 6.5. Do not skip or mix up these steps to ensure safe handling and best performance.
Note
Application notes are available for various samples at Buchi. These notes work as digestion recipes
and give detailed instructions how to process specific sample materials. For application notes,
contact your Buchi application specialist or your local distributor.
6 .4 .1 Preparational steps
Start-up the SpeedDigester. 1.
Set the required preheating temperature and let the system heat up 10-15 minutes minimum. 2.
Prepare the sample tubes according to the type of digestion under safe conditions. 3.
➡ The samples are now ready to be digested.
6 .4 .2 Starting a digestion process
Install the rack(s) according to section 6.2.3. For peroxide digestion a 'Suction module H 4.
2
O
2
' with
funnels must be installed!
➥ Place glass caps (order no. 040049) into every unused position of the rack
➥ Place insulation caps into every unused postion at the insulation plate
➥ To securely withdraw harmful fumes, switch on the suction unit (Scrubber or water jet pump)
before inserting the racks into the instrument!
The digestion process starts, as soon as the sample tubes heat up in the instrument. 5.
➥ Depending on the sample material and acid / peroxide composition it might be necessary to vary
the digestion temperature at different time intervals (digestion program).
➥ During the digestion process it is necessary to add peroxide. Carefully and slowly(!) add peroxide
into every sample probe via the funnel of the suction module (see following illustration).
At the end of the digestion switch off the instrument via the mains switch. 6.
➡ The samples are now digested. Follow-up actions are described in section 6.5.