Metrohm 833 IC Liquid Handling Unit - Manual (Page 72)

7 833 IC Liquid Handling Dialysis Unit
833 IC Liquid Handling Unit / Instructions for Use 8.833.1003
64
The below illustration shows an example of such a determination for
anions using the 6.2714.010 Dialysis membrane from Metrohm
(cellulose acetate; thickness= 115 µ m; pore size= 0.2 µ m). A standard
solution containing 10 mg/L of each of the individual anions was used
as the sample and dialyzed for10 min (mains frequency 50 Hz).
7.6.3 Determining the dialysis time
After the optimal transfer time has been determined the optimal dialysis
time must also be determined, this depends on the total ionic
concentration. The dialysis time with the stopped acceptor solution flow
must be selected so that 100% of the sample concentration is achieved
in the acceptor solution. For the 6.2714.010 Dialysis membrane from
Metrohm (cellulose acetate; thickness= 115 µ m; pore size= 0.2 µ m)
the optimal dialysis time is 10 min for a total ionic concentration
≥ 5 mg/L.
If a different dialysis membrane is used or if a total ionic concentration
< 5 mg/L is measured the optimal dialysis time must be determined by
measuring the recovery rate as a function of the dialysis time. Proceed
as follows:
0.0
2.0
4.0
6.0
8.0
10.0
12.0
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0
Transferzeit [min]
Konzentration [mg/L]
Fluorid
Chlorid
Nitrit
Bromid
Nitrat
Phosphat
Sulfat