Multi-walled carbon nanotube modified with 1-buthyl 3-methyl imidazolium hexaflouro phosphate supported on sawdust as a selective adsorbent for solid phase extraction of Bi(III)

► A new adsorbent is proposed for solid phase extraction of bismuth. ► Multi-walled carbon nanotubes dispersed in ionic liquid supported on sawdust is used as adsorbent. ► The method was applied to determination of bismuth in water and drug samples. ► The procedure is simple, selective and eco-friendly.