Bismuth in drinking water

Bismuth is considered as a metal with a very low toxicity. However, in high concentrations toxic effects have been described. There is no guideline value for bismuth in the World Health Organization’s «Guidelines for Drinking-water Quality» because typical levels usually found in drinking water are of no concern.

Anodic stripping voltammetry is a viable, less sophisticated alternative to atomic absorption spectroscopy (AAS) for the determination of bismuth in drinking water. While AAS (and competing methods) can only be performed in a laboratory, anodic stripping voltammetry can be used in the laboratory or alternatively in the field with the 946 Portable VA Analyzer. The determination is carried out on the scTRACE Gold electrode.

Bottled mineral water

Figure 1. 946 Portable VA Analyzer (scTRACE Gold version)

The scTRACE Gold is electrochemically activated prior to the first determination. In the next step, the water sample and the supporting electrolyte are pipetted into the measuring vessel. The determination is carried out with the 884 Professional VA or with the 946 Portable VA Analyzer using the parameters specified in Table 1. The concentration is determined by two additions of a standard addition solution.

Figure 2. 884 Professional VA fully automated for VA

**Table 1.** Parameters
Parameter	Setting
Mode	DP – Differential Pulse
Deposition potential	-0.1 V
Deposition time	30 s
Start potential	-0.2 V
End potential	0.3 V
Peak potential Bi	0.08 V

scTRACE Gold

The limit of detection of the method is about 1 μg/L with the 946 Portable VA Analyzer, and approximately 0.03 μg/L with the 884 Professional VA.

Figure 3. Determination of bismuth (946 Portable VA Analyzer; 30 s deposition time)

**Table 2.** Results of the measurement of Bi in tap water
Sample	Bi (μg/L)
Tap water	20.4

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Metrohm India

Annai Indira Nagar, Thoraipakkam
600097 Chennai

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Internal references: AW VA CH4-0568-042018, AW VA CH4-0577-022019