| HIRANUMA APPLICATION DATA | Automatic Titrator | Data No. | G10 | Apr. 5,2019 |
| Metals | Quantitative determination of copper ion in plating solution |
1. Abstract
The photometric titration using a photometric probe is generally applied for the determination of copper ion (Cu2+). However, the measurement of cloudy or colored sample has difficulty to analyze with the photometric titration. The measurement using copper ion-selective electrode performs the potentiometric titration which it is not affected by the suspended particle and the indicator reagent is not required for the titration.
| Cu²⁺ ＋ Na₂EDTA → Cu-EDTA ＋ 2Na²⁺ |
This report introduces an example of the measurement for copper ion in plating solution with chelatometric titration using copper ion-selective electrode.
2. Configuration of instruments and Reagents
| (1) | Configuration of instruments | ||
| Main unit | : | Hiranuma Automatic Titrator COM series | |
| Electrodes | : | Copper ion-selective electrode CUi-081 Reference electrode RE-201Z |
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| (2) | Reagent | ||
| Titrant | : | 0.1 mol/L EDTA standard solution | |
| Buffer solution | : | Sodium acetate- acetic acid buffer pH 5 Dissolve 13.6 g of sodium acetate in DI water and prepare 100 mL (1 mol/L) of the solution. Adjust the pH to 5 by adding acetic acid. |
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3. Measurement procedure
| (1) | Dispense 5 mL of sample into a 100 mL beaker with volumetric pipette. |
| (2) | Add about 50 mL of DI water. |
| (3) | Add 5 mL of buffer solution with micropipette. |
| (4) | Immerse electrode into sample solution and titrate with 0.1 mol/L EDTA standard solution. |
4. Measurement conditions and results
Examples of titration conditions
Measurement results
| Number of measurement |
Size (mL) |
Titrant volume(mL) |
Concentration (g/L) |
|---|---|---|---|
| 1 | 5 | 7.623 | 9.639 |
| 2 | 5 | 7.603 | 9.614 |
| 3 | 5 | 7.622 | 9.638 |
| 4 | 5 | 7.611 | 9.624 |
| 5 | 5 | 7.595 | 9.603 |
| Statistic calculation |
Average | 9.62 g/L | |
| Standard deviation | 0.02 g/L | ||
| Coefficient of variation | 0.16 % | ||
Example of titration curve
5. Note
The reading of the potential might decrease with repeated use of the copper ion-selective electrode. Polishing the surface of the copper ion-selective electrode with a fine sandpaper (P800 or finer) improves the condition of the electrode.
| Keywords： | Copper ion, Potentiometric titration, Copper ion-selective electrode, Plating solution, Chelatometric titration |
*Some measurement would not be possible depending on optional configuration of system.
