饮用水中的铊
AN-V-228
2020-05
zh
Method using the scTRACE Gold modified with a silver film
地表水中的铊含量是工业废水的一个指标,一旦被人体吸收会严重危害健康。在经过银膜修饰的 scTRACE Gold 上使用阳极溶出伏安法可以轻松监测铊的浓度。这种无毒方法可测定 10-250 µg/L 之间的铊浓度,可使用 946 便携式重金属快速分析仪进行测定。
Presence of thallium in surface water is an indicator of industrial effluents and poses a serious health hazard if imbibed. Monitoring of thallium concentration can easily be done with anodic stripping voltammetry on the silver film modified scTRACE Gold.
This non-toxic method allows the determination of thallium concentrations between 10–250 µg/L. The determination is carried out with the 946 Portable VA Analyzer. The main advantage of this procedure is the unique design of the sensor, the scTRACE Gold electrode. It consists of a gold microwire working electrode, Ag/AgCl reference electrode, and a carbon auxiliary electrode on a ceramic substrate. The electrode is easy to handle and does not need extensive maintenance such as mechanical polishing. The possibility to re-plate the silver film allows a quick and easy regeneration of the sensor. This method is best suited for measurements in the field.
Drinking water, mineral water, sea water
Prior to the first determination, the silver film is deposited from a silver solution on the scTRACE Gold electrode. In the next step, the electrodes are cleaned with ultrapure water and the measuring vessel is emptied. The water sample and the supporting electrolyte with EDTA are pipetted into the measuring vessel. The determination of thallium is carried out with a 946 Portable VA Analyzer using the parameters specified in Table 1. The concentration is determined by two additions of a thallium standard addition solution.
The scTRACE Gold is electrochemically activated prior to the first determination.
| Parameter | Setting |
|---|---|
| Mode | SQW – Square wave |
| Deposition potential | -1. 0 V |
| Deposition time | 90 s |
| Start potential | -1.0 V |
| End potential | -0.25 V |
| Peak potential Tl | -0.62 V |
- scTRACE Gold
The method is suitable for the determination of thallium concentrations up to 150 µg/L. The limit of detection with 90 s deposition time is approximately 10 µg/L.
| Sample | Tl (µg/L) |
|---|---|
| Tap water spiked with 30 µg/L Tl | 30.7 |
Internal reference: AW VA CH4-0588-122019