Determination of volatile metallic elements in water using flow injection hydride generation coupled with ICP-EOS

Abstract

In the study were developed two methods for quantification of mercury and tin in water samples. The methods were performed with Perkin Elmer 5300 DV Optima ICP-EOS spectrometer by continuous hydride generation using flow injection analysis system. For detection of mercury, a pre-treatment step was applied using an ultrasonic bath and a mixture of acids and oxidants (such as sulphuric acid, nitric acid, potassium permanganate, potassium dichromate). Mercury was detected at 194.168 nm wavelength, using as reducing agent 0.3% of NaBH4 in 0.5% NaOH solution. The detection limit of the method is 0.1 µg/L, precision is 3.2% and uncertainty of measurement is 8.5%. Tin was detected at 189.927 nm wavelength. To generate tin gas, sample solutions in 4% boric acid and 0.5 M HCl were mixed in line with a solution of 1% NaBH4 and 2% NaOH. The detection limit of the method is 0.2 µg/L, sufficient for tin levels commonly found in water samples. Precision of the method is 3.1% and uncertainty of measurement is 9.3%.