Metrohm Dialysis 6.5330.100, Instruction Manual

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4.1 Operation
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IC equipment Dialysis 6.5330.100
3 Determining the optimum transfer time
￭
Record the area in relation to the transfer time and determine the
optimum transfer time.
Figure 5 exemplifies this relation.
0.0
2.0
4.0
6.0
8.0
10.0
12.0
10 15 20 25 30 35 40 45
Fluoride
Chloride
Nitrite
Bromide
Nitrate
Phosphate
Sulfate
Fluoride
Chloride
Nitrite
Bromide
Nitrate
Phosphate
Sulfate
Transfer time [sec]
Ar
ea [µS/cm*min]
Figure 5 Area / transfer time diagram
According to this curve, the optimum transfer time is between 27
and 32 seconds.
Determining the dialysis time
After the optimum transfer time has been established, the optimum dialy-
sis time must be determined. This time depends on the total ion concen-
tration in the sample.
The dialysis time is the time during which the acceptor flow is stopped
and only sample is pumped. This time must be chosen in such a way that
100% of the sample concentration is achieved in the acceptor solution.
For the dialysis cell (6.2729.100) with the dialysis membrane
(6.2714.010) (Cellulose acetate; thickness = 115 µm; pore size = 0.2 µm)
and a total ion concentration of
≥
5 mg/L in the sample, the guideline
value for the dialysis time is 10 minutes.
For the Dialysis cell Low Volume (6.2729.200) with the dialysis mem-
brane (6.2714.010) (Cellulose acetate; thickness = 115 µm; pore size =
0.2 µm) and a total ion concentration of
≥
5 mg/L in the sample, the
guideline value for the dialysis time is 6 minutes.
This guideline value must be verified for each installation.