Determination of polyorganosiloxanes (by silicon) in water by extraction high-resolution continuum source electrothermal atomic absorption spectrometry

Abstract

A method for the determination of polyorganosiloxanes (by silicon) in water using high-resolution electrothermal atomic absorption spectrometry with a continuous spectrum source and preliminary extraction of polyorganosiloxanes by benzene from the analyzed sample is proposed. The quantitative determination of polyorganosiloxanes (by silicon) was carried out on a contrAA® 700 atomic absorption spectrometer in a cross-heating furnace. Natural water was used to optimize the parameters of the temperature – time program of the atomizer. To eliminate chemical interference during silicon determination by proposed method, graphite cuvettes were modified with a permanent modifier to form a carbide coating. A solution of sodium tungstate was used as a permanent modifier. Thermal stabilization of silicon in a graphite furnace was achieved in the presence of a mixed palladium-magnesium modifier in the nitrate form. The accuracy of the results was confirmed by spike test. The developed method of analysis was used to determine the content of polyorganosiloxanes (by silicon) in natural water. The metrological characteristics of the method were assessed in the range of determined silicon contents 0.01 – 100 mg/dm3.