On-site determination of tin in geological and water samples using novel organic reagent with iodide

A new, simple and sensitive method for spectrophotometric determination of tin (IV) with iodide and amide is described. The Sn(IV)-I(-) complex is extracted with chloroform solution of amide (N-phenylacetamide, N-alkylacetamide, alkyl=butyl, phenyl, hexyl and octyl group) in the strong sulphuric acid solution. Among five amides studied, N-octylacetamide (OAA) has been selected as it yielded best sensitivity. The apparent (at twofold preconcentration) molar absorptivity with respect to tin is (2.40)x10(5)Lmol(-1)cm(-1) at lambda(max), 410nm. The detection limit of the method is 4microgL(-1) Sn. The method is free from interferences of common ions that are normally associated with Sn. The method is highly sensitive and found to be applicable for the rapid determination of tin in water samples at micro-gram levels.