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http://www.chemweb.com/alchem/articles/1048177160862.html
from The Alchemist . If you can't be bothered registering
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7 April 2003
There are some metals which are unfavourable in water even in trace amounts, for example, mercury, thallium and lead. Low but harmful levels are difficult to elucidate as the analysis requires large, complicated and expensive facilities. Now Moscow scientists have designed a palm-sized device which is as precise and sensitive as its cumbersome counterpart.
Vladimir Yagov and his colleagues from the Vernadsky Institute of Geochemistry and Analytical Chemistry have built a unique device to solve sensitive analytical tasks. The device is based on a combination of two methods electrochemistry and luminescence.
The concept behind the device was recently described by chemists in Finland. They found that in the course of electrolysis some dissolved metals (mercury, thallium and lead are among them) can emit light. To reveal the phenomenon certain conditions are required: an aluminium electrode and short cathode pulses. The metal ions gain an extra electron and become excited. In the excited state the ion has more energy, so it emits a photon and then falls into the ground state. By registering photons it is possible to count all the metal ions dissolved in the water sample.
Yagov and his team have studied this phenomenon and discovered two more metals that emit light (namely tin and indium) and developed a theoretical model describing all the data. They found a way to solve some initial problems, such as increasing the life-time of the electrode, and developed this in a pilot device.
The main advantage of the device is its small size in combination with high sensitivity. The results of analyses are processed with specially developed computer software.
For further information contact: Vladimir Yagov, e-mail: zuev@geokhi.ru.
Note: This document has been translated from Russian.
Olga Maksimenko
from The Alchemist . If you can't be bothered registering
, scroll down!7 April 2003
There are some metals which are unfavourable in water even in trace amounts, for example, mercury, thallium and lead. Low but harmful levels are difficult to elucidate as the analysis requires large, complicated and expensive facilities. Now Moscow scientists have designed a palm-sized device which is as precise and sensitive as its cumbersome counterpart.
Vladimir Yagov and his colleagues from the Vernadsky Institute of Geochemistry and Analytical Chemistry have built a unique device to solve sensitive analytical tasks. The device is based on a combination of two methods electrochemistry and luminescence.
The concept behind the device was recently described by chemists in Finland. They found that in the course of electrolysis some dissolved metals (mercury, thallium and lead are among them) can emit light. To reveal the phenomenon certain conditions are required: an aluminium electrode and short cathode pulses. The metal ions gain an extra electron and become excited. In the excited state the ion has more energy, so it emits a photon and then falls into the ground state. By registering photons it is possible to count all the metal ions dissolved in the water sample.
Yagov and his team have studied this phenomenon and discovered two more metals that emit light (namely tin and indium) and developed a theoretical model describing all the data. They found a way to solve some initial problems, such as increasing the life-time of the electrode, and developed this in a pilot device.
The main advantage of the device is its small size in combination with high sensitivity. The results of analyses are processed with specially developed computer software.
For further information contact: Vladimir Yagov, e-mail: zuev@geokhi.ru.
Note: This document has been translated from Russian.
Olga Maksimenko