Direct determination of ultratraces of thallium in water by flow-injection—differential-pulse anodic stripping voltammetry

✍ Scribed by Zenon Lukaszewski; Wlodzimierz Zembrzuski; Anna Piela

• Publisher: Elsevier Science
• Year: 1996
• Tongue: English
• Weight: 556 KB
• Volume: 318
• Category: Article
• ISSN: 0003-2670
• DOI: 10.1016/0003-2670(95)00436-x

✦ Synopsis

A direct method for the determination of thallium concentrations on the order of lo-" M was developed. Long deposition times (up to 2 h) performed in the flow system with circulation of the analyte ensured the necessary preconcentration. A large volume sample (100 ml) was used to prevent depletion of thallium during deposition. The flow-through cell of a wall-jet type with the mercury film electrode based on an epoxy resin impregnated graphite was used.

The detection limit of the method is 2 ng I-' at 90 min preconcentration). A spike of 0.05 M EDTA was found to be an effective preservative for fresh water samples. Numerous examples of determinations of thallium in tap water and river water are given.