Famous pigment, medical cure, notorious poison – toxic arsenic determined with new, low-cost sensor

Page from Metrohm Info customer magazine with application know-how and tips and tricks
The cultural history of arsenic is fascinating. In present times, however, arsenic is mainly considered a threat to the health of millions of people as it contaminates their drinking water in many regions of this planet. An article recently published (MI-2014-1-EN-AP-1) sheds light on the various uses of arsenic in the past and presents a new, straightforward and affordable method to determine its toxic species in drinking water.
Throughout the course of history, people have found uses for the various properties of arsenic and its compounds. Red and yellow arsenic sulfides (As2S3 and As4S4) were used in antiquity as makeup and for hair removal. Artists used arsenic compounds as pigments, and, to name just one medical application: the first effective drug to be used against syphilis was the arsenic compound arsphenamine (1910). The best-known use of the element with the atomic number 33, however, is as a poison. People in various regions of the world struggle even today with arsenic as a contaminant in drinking water.

The usual spectroscopic methods (ICP-MS, AAS) for the determination of toxic arsenic in drinking water are either very expensive or challenging to use. An alternative method that is much easier to use and much less expensive at the same time is voltammetric determination with the scTRACE Gold.

This new, screenprinted sensor can be used without any preparation; measuring results are available after only 10 minutes on average, and the detection limit for arsenic is well below the 10 µg/L stipulated by the latest legislation in the US and the EU.