Metrohm 838 Advanced Sample Processor Installation Instructions - Manual (Page 55)

3.5 Connection to Metrohm IC systems
Metrohm 838 Advanced Sample Processor, Installation 49
⇒ The total analysis time per sample comprises the times for dialy-
sis and for the chromatogram.
B) Dialysis of the next sample is performed as early as the phase in
which one sample is being chromatographically separated.
⇒ The total analysis time per sample is shortened to the time re-
quired for one chromatogram.
A) Dialysis and chromatogram of a sample in one sequence
Entry of the program for the 838 Advanced Sample Processor:
•
Dialysis by stop flow procedure, dialysis time 10 min.
001 Move sample
002 Lift work
003 Ctrl Pump 833 on
004 Pump
on
005 Wait 120 s
006 Ctrl Pump 833 off
007 Wait
420 s
008 Ctrl FILL B/STEP 1
009 Wait
180 s
010 Ctrl ZERO 1
011 Ctrl FILL A 1
012 Ctrl Pump 833 on
013 Wait
30 s
014 Ctrl INJECT A 1
015 Ctrl Pump 833 off
016 Pump
off
− Move needle to sample position
− Move lift with needle to working height
− Switch on pump 833 (acceptor solution)
− Pump sample solution
− Wait for rinsing time
− Switch off pump 833, dialysis starts
− Dialysis time + 180 s
− Trigger step of suppressor unit
− Wait until baseline is stable (= 10 min. dialysis time)
− Trigger autozero on 819/1 IC Detector
− Switch over injection valve in 820 to "Fill"
− Pump acceptor solution
− Transfer time (must be determined)
− Switch over injection valve in 820 to "Inject"
− Stop pumping acceptor solution
− Stop pumping sample solution
B) Chromatogram with simultaneous dialysis of the next sample
The following program descriptions prerequire chromatograms with a
duration of e. g. 20 minutes. Dialysis of the next sample is started 10
minutes prior to the end of each chromatogram. A waiting time of 600
seconds (see below) is entered for this purpose in line 008 of the 838
program in System Dialysis.smt. This time information may need to be
adapted to specific requirements.
A program which controls both injection of the dialysed sample and
also dialysis of the next sample ('Dialysis.smt') is written for the 838 Ad-
vanced Sample Processor in the existing system.
In order to also process the first and last sample of a Sample Queue
correctly, it is necessary to create programs in separate system files for
these samples. The 838 program in system file 'Start-Dialysis.smt' only
starts dialysis of the first sample. 'End-Dialysis.smt' is required for injec-
tion of the last dialysed sample.