Metrohm 746 VA Trace Analyzer - Manual (Page 406)

5.7.3 Alphabetical instruction list
746 VA Trace Analyzer / 747 VA Stand
5-255
Examples Determination of cadmium and lead by stripping voltammetry on the 695
Autosampler (with predilution 1:10'000):
Method ASV-2 .mth OPERATION SEQUENCE
Title Determination of cadmium and lead
================================================================================
Instructions t/s Main parameters Auxiliary parameters
––––––––––––– ––––– ––––––––––––––––––––––––– –––––––––––––––––––––––––
1 (PREP
2 SMPL/F V.fraction mL V.total L
3 DOS>A Soln.name Buffer V.add 4.950 mL
4 F>A addition FEED -> AUX V.add 0.050 mL
5 VMIX Cycles 2 V.mix 4.000 mL
Rack pos. SA
6 PREP)
7 DOS>M Soln.name Buffer V.add 9.900 mL
8 A>M addition AUX -> MEAS V.add 0.100 mL
9 >PREP
10 PURGE
11 STIR 600.0 Rot.speed 2000 /min
12 (ADD
13 (REP
14 PURGE
15 STIR 20.0 Rot.speed 2000 /min
16 ØPURGE
17 SEGMENT Segm.name CdPbASV
18 REP)2
19 ADD>M Soln.name PbCD V.add 0.020 mL
20 ADD)2
21 ØMEAS U.standby mV
22 RINSE Cycles 1 V.rinse 40.000 mL
23 RINSE Cycles 2 V.rinse mL
24 END
Method ASV-2.mth SEGMENT
CdPbASV
================================================================================
Instructions t/s Main parameters Auxiliary parameters
––––––––––––– ––––– ––––––––––––––––––––––––– –––––––––––––––––––––––––
1 STIR 5.0 Rot.speed 2000 /min
2 HMDE Drop size 4 Meas.cell normal
3 DPMODE U.ampl 50 mV t.meas 20.0 ms
t.step 0.20 s t.pulse 40.0 ms
4 MEAS 60.0 U.meas -800 mV
5 ØSTIR 5.0
6 SWEEP 20.6 U.start -800 mV U.step 6 mV
U.end -200 mV Sweep rate 30 mV/s
7 END .
In the sample preparation block (PREP ... PREP) , 0.05 mL sample from
the sample vessel (FEED) are transferred to the auxiliary vessel (AUX)
where they are mixed with 4.95 mL buffer. 0.1 mL of this solution are then
transferred to the measuring vessel, mixed with 9.9 mL buffer and
purged for 10 min with stirring. During this time, the PREP block for the
next sample is started. After purging, lead and cadmium in the segment
PbCdSV are determined by stripping voltammetry with double standard
addition.
see also PREP), >PREP