Determination of Total Organosilicon in Titanium Dioxide Pigment by Inductively Coupled Plasma Atomic Emission Spectrometry

Abstract

Some types of titanium dioxide were treated with silicone oil to change the hydrophobic or hydrophilic character of the product. To determine the added amount of silicone oil, an ICP-AES method was developed. This method is based on the reaction of hydrofluoric acid with the silicone oil and direct injection of the gaseous decomposition products into the plasma. The calibration curve was established by addition of silicone oil to an untreated titanium dioxide sample. The curve is linear up to 0.2% Si. The relative standard deviation for eight replicates of a sample containing 0.095% of Si is 2.32%. The method was compared with an XRF method (total Si) and good agreement was found between both methods.