Inversion-voltammetric determination of heavy metal ions on electrodes modified with mono- and bis-N-thiophosphoryl thiourea

A method is proposed for determining Ni2+, Co2+, Cu2+, Cd2+, and Pb2+ ions by inversion voltammetry on carbon-paste electrodes modified with N-diisopropoxythiophosphoryl-N'-phenyl thiourea and its derivatives: N,N'-bis-(diisopropoxythiophosphorylamidothiocarbonyl)-1,5-diamino-3-oxapentane, N,N'-bis(diisopropoxythiophosphorylamidothiocarbonyl)-1,8-diamino-3,6-dioxaoctane and N,N'-bis-(diisopropoxythiophosphorylaminothiocarbonyl)-1,10-diaza-18-crown-6.