Metrohm 789 Robotic Sample Processor XL - Manual (Page 140)

6.2 Standard methods
132 Metrohm Sample Processor, Annex
6.2.3 KF_ext.
Standard method for coulometric or volumetric Karl Fischer determina-
tions. The samples are pipetted from sealed vials into an external condi-
tioned coulometer or KF titration cell.
Required instruments and cables:
• Metrohm Coulometer (756 or 831) or
• Metrohm KF Titrator (e.g. 795 Titrino or 835 Titrando) with
6.2148.010 Remote Box
• 786 Swing Head with robotic arm for sample transfer (6.1462.030 or
6.1462.040)
• 803 Magnetic Stirrer or 804 Ti Stand with 802 Rod Stirrer connected
to MSB1
• 800 Dosino with 807 Dosing unit (recommended: 10 mL cylinder,
6.3032.210) and 6.1562.100 Pipetting tubing
• 6.2141.020 Remote cable
• Sample transfer accessory set (6.5619.000)
Special features:
Samples are pipetted directly from the sample beaker into the external
titration cell. Freshly titrated conditioning solution from the KF cell is
used as the transport medium for pipetting.
The external Position 1 with the working height for moving to the titration
cell must be set in the tower configuration.
789 Sample Proc. XL 11122 5.789.0011
parameters
method KF ext
number of samples: rack
>start sequence
1 CTL:Rm: INIT
2 STIR: MSB1 : ON s
3 CTL:Rm: START device1
4 MOVE 1 : ext.1
5 SCN:Rm : Cond ok
6 WAIT: pause 60 s
7 SCN:Rm : Cond ok
8 LIFT: 1 : work mm
9 DOS: 1.4 : eject mL
10 DOS: 1.1 : -5.0 mL
11 DOS: 1.2 : endVol mL
12 DOS: 1.1 : -2.0 mL
13 DOS: 1.2 : eject mL
14 DOS: 1.2 : endVol mL
15 MOVE 1 : spec.1
16 LIFT: 1 : work mm
17 SCN:Rm : Cond ok
18 WAIT: pause 60 s
19 SCN:Rm : Cond ok
>sample sequence
1 MOVE 1 : ext.1
2 DOSRATE 1 5
3 FILLRATE 1 5
4 DOS: 1.1 : -0.1 mL
5 LIFT: 1 : work mm
6 DOS: 1.1 : -0.5 mL
7 LIFT: 1 : shift mm
8 DOS: 1.1 : -0.1 mL
- Report header with device ID and program version
- Method name
- No. of samples (here whole sample rack)
- Initialize Remote interface
- Switch on stirrer
- Start conditioning
- Move robotic arm to KF cell
- Wait for conditioning
- Stabilization of "Cond." condition
- Wait for conditioning
- Insert needle into KF cell
- Eject dosing cylinder into waste container
- Aspirate conditioning solution into dosing cylinder
- Eject dosing cylinder into waste container
- Aspirate conditioning solution into pipetting tubing
- Eject dosing cylinder into waste container
- Piston to max. volume mark
- Move robotic arm to conditioning beaker
- Run lift to working height
- Wait for conditioning
- Stabilization of "Cond." condition
- Wait for conditioning
- Move robotic arm to KF cell
- Aspirate air-gap bubble
- Pierce KF cell
- Aspirate conditioning solution
- Run lift to shifting height
- Aspirate air-gap bubble