Preparation of a high-concentration nm-size ceramic silicon carbide slurry for the ICP-OES determination of ultra-trace impurities in a sample

A high-concentration with low viscosity ceramic silicon carbide (SiC) slurry prepared for ICP-OES determination of ultra-trace impurities is described in this paper. Good fluidity can be kept up to the slurry concentration as high as 30% (m v(-1)) by adding 2% polyethylene imine (PEI) as a dispersant at pH 4.0. Stability of the high content slurry of nm-size SiC is characterized by zeta potential measurement and viscosity measurement, and medium pH is experimentally optimized. The analysis can be calibrated using simple aqueous standards in case a high-concentration slurry is nebulized. Owing to extremely low blanks and unusually highly slurry concentration (20% m v(-1)), extraordinarily low limits of detection ranging from 2 (Mn, Ti) to 100 (Al) ng g(-1) could be achieved.