DETERMINATION OF SELENIUM IN DRINKING WATER WITH A SIMPLE FIELD DEVICE

ABSTRACT

A new method for the determination of total selenium in drinking water in the low ppb range was developed and optimized. The method use field device Supralab FD which was previously designed for the determination of arsenic in drinking water. The method relies on the formation of selenium hydride and its reaction with sodium perborate impregnated on a support to form a colored product, elemental selenium, which is optically detected. As a reductant, sodium borohydride is used. Thus, only Se(IV) reacts whereas Se(VI) cannot be reduced directly requiring pre-reduction with hydrochloric acid. The limit of detection of method (3σ) is 0.7 µg/dm³, the limit of quantification is 2 µg/dm³. The total reaction time for concentration up to 10 µg/dm³ is 5 min; higher concentrations require up to 15 min.

Keywords:

• Selenium
• Hydride generation
• Optical determination
• Drinking water

Acknowledgments