Metrohm 757 VA Computrace - Manual (Page 157)

7.6 Standard addition technique
757 VA Computrace – Software
147
15. Enter the Sample ID (used as part of the determination file
name) in the PLACE SAMPLE window and click <OK> .
16. Each time a standard addition is required in the
MANUAL AD-
DITION window, add the standard addition solution using a
pipette.
Use manual standard addition with solution exchange
In the manual standard addition with solution exchange, a new
sample solution is used for every standard addition. Proceed as
follows:
1. Click on or MAIN WINDOW / Mode / Determination .
2. Click on or MAIN WINDOW / Window / Working method
specification to open the WORKING METHOD SPECIFICATIONS
window.
3. Load the desired method into the WORKING METHOD SPECIFI-
CATIONS window (see How to load a method).
4. Select Standard addition in the Calibration field of the WORKING
METHOD SPECIFICATIONS window.
5. Select Manual in the Addition field of the WORKING METHOD
SPECIFICATIONS window.
6. Select Batch with solution exchange in the Technique field of the
WORKING METHOD SPECIFICATIONS window.
7. Click to open the EDIT WORKING METHOD PA-
RAMETERS window.
8. Select the
Determination
tab (see section 5.2) and enter
Sam-
ple identifier , Sample amount , Cell volume , and the number of
spiked solutions in the No. of cells field.
9. Select the Substances tab (see section 5.2) and make sure
that for each substance entered in the table the concentra-
tions of the spiked sample solutions are defined in the
CELL
CONCENTRATIONS window which is opened by clicking on the
button.
10. Close the EDIT WORKING METHOD PARAMETERS window by
clicking <OK> .
11. Place the sample solution in the measuring vessel at the 757
VA Computrace Stand.
12. Click on or MAIN WINDOW / Window / Monitor to open the
MONITOR
window.