On-line ultrasound-assisted dispersive micro-solid phase extraction using graphitic carbon nitride microparticles combined with ICP-OES for the preconcentration and determination of thorium

In this study, on-line ultrasound-assisted dispersive micro-solid phase extraction technique is introduced for the separation and ICP-OES determination of thorium in aqueous samples. In this method, microparticles of g-C₃N₄ were dispersed into the sample using ultrasonic radiation and Th(IV) ions were directly adsorbed by the sorbent. The sample solution was then passed through a membrane filter and the adsorbed Th(IV) ions were subsequently eluted directly into the ICP-OES nebulizer. The Limit of detection of developed method was 0.05 μg L^-1. The developed on-line technique eliminates the centrifugation step in order to simplify and speed up the extraction procedure. (author)