Silicon determination by inductively coupled plasma atomic emission spectrometry after generation of volatile silicon...

A method for the determination of silicon by inductively coupled plasma atomic emission spectrometry (ICP-AES) is described. The procedure is based on a discontinuous generation of volatile silicon tetrafluoride in concentrated sulphuric acid medium after injecting 125 mul of 0.1%, w/v sodium fluoride solution into 100 mul of the sample. The gaseous silicon tetrafluoride is fed directly into the ICP torch by a flow of 250 ml min(-1) Ar carrier gas. The calibration curve was linear up to at least 100 mug ml(-1) of Si(IV) and the absolute detection limit was 9.8 ng working with a solution volume of 100 mul. The relative standard deviation for six measurements of 10 mug ml(-1) of Si(IV) was 2.32%. The method was applied to the determination of silicon in water and iron ores.