Soil thin-layer chromatography of heavy metal cations with surfactant-modified mobile phases: Mutual separation of Zinc(II), Cadmium(II), and Mercury(II)

Abstract

Thin-layer chromatography of ten metal ions has been performed on pure soil layers; the mobile phases were aqueous organic and inorganic fertilizer solutions, solutions of aqueous inorganic fertilizer mixed with potassium, sodium, or calcium halide, and aqueous anionic sodium dodecyl sulfate (SDS) solutions with added iodides or chlorides of K, Na, or Ca. A novel mobile phase, 1:9 ( v/v ) 0.001 m SDS-NaCl, was identified for rapid separation of mixtures of Zn 2+ , Cd 2+ , and Hg 2+ .The metal cation mobility observed on pure soil layers with these mobile phases was compared with that obtained on organic-matter-free soil layers. A general trend toward increased metal ion mobility on organic matter-free soil layers was observed. Substitution of SDS by a cationic ( N,N,N -cetyl- N -trimethylammonium bromide) or a nonionic (Tx-100 or Brij 35) surfactant in the mobile phase hampered separation of Zn 2+ from Cd 2+ and Hg 2+ . The effect of inorganic additives (sodium molybdate, KSCN) and acids (oxalic, tartaric...