Cold vapour atomic absorption method for the determination of mercury in iron(III) oxide and titanium oxide pigments using slurry sample introduction

Abstract

A simple and rapid method for the determination of mercury in commercial iron(III) oxide and titanium oxide pigments combining a slurry sampling procedure with the cold vapour technique is described. The samples are suspended in water containing 0.02% m/v sodium hexametaphosphate and mercury vapour is generated from a hydrochloric acid medium by adding sodium tetrahydroborate(III). A detection limit of 5 ng g^–1 of mercury is achieved. Calibration can be performed using standard aqueous mercury solutions. Excellent agreement is found between the results of the slurry sampling procedure and those obtained for iron(III) oxide pigments using lengthy conventional acid dissolution procedures.