Lead selective electrodes based on thioamide functionalized calix[4]arenes as ionophores

Abstract

Lead selective electrodes based on a di-and tetrathioamide functionalized calix [ 41 arene as ionophores were investigated. The Pb(II)-response functions exhibited almost theoretical Nernstian slopes in the activity range 10-6-10-2 M of lead ions. For both ionophores a preference for lead over other cations was observed. The best results were obtained for membranes containing the tetrathioamide derivative (ionophore 1)) potassium tetrakis(4-chlorophenyl)borate and a-nitrophenyl octyl ether as a plasticizer. This electrode showed greatly improved selectivity over copper, zinc and cadmium ions as compared with commercial solid-state lead selective electrodes.

New solid-state organic membrane based leadselective micro-electrode

“…Hence, the microelectrode can be used for at least four months with practically unimpaired performance. Moreover, the suggested micro-electrode properties are almost similar or even somewhat better (life span) than the results observed for the lead macro-electrode based on the same ionophore [20]. The recently developed, nebulization technique of the organic membrane-sensitive layer in combination with the electrochemical treatment of the substrate surface significantly improves the adhesive properties of the membrane to the substrate surface, decreases the leaching out of the ionophore and plasticizer, stabilizes the organic membrane, and consequently increases the micro-electrodes' life-time (4> months).…”

“…The suggested micro-electrode incorporating this ionophore has been electrochemically evaluated according to IUPAC recommendations in terms of sensitivity, stability, selectivity and reliability. In order to assess the reliability of the suggested micro-electrode, its response properties were compared with those reported for the bulk macro-electrode prepared by the same ionophore [20]. The data obtained are collected in Table 1.…”

“…In this paper, we describe the fabrication and characterization of PVC membrane-based microsensors using tert-Butylcalix [4]arene-tetrakis(N,N-dimethylthioacetamide) as lead ionophore [20], deposited on gold thin-film silicon micro-chips by the nebulization technique in combination with substrate surface treatment. The reliability of the suggested micro-sized lead sensors in comparison to independent standard methods using ICP-AES has been assessed.…”

Influence of Incorporated Lipophilic Particles on Ion Fluxes Through Polymeric Ion‐Selective Membranes

“…Preliminary experiments have been made with Pb 2 -ISEs based on the ionophores N,N,N',N'-tetradodecyl-3,6-dioxaoctanedithioamide (ETH 5435) [8] and 4-tert-butylcalix [4]arene-tetrakis(thioacetic acid dimethylamide) [18,39]. In both cases, the apparently super-Nernstian response could be avoided in a similar way as shown in Figure 4 for the Ca 2 -ISE.…”

Simultaneous Titration of Ternary Mixtures of Pb(II), Cd(II) and Cu(II) with Potentiometric Electronic Tongue Detection

“…For building the sensor array, there were used commercial formulation membranes [18][19][20][21][22][23] or others developed in our group [24]. The ion selective electrodes (ISEs) were constructed in asymmetric configuration with a solid electrical contact made from a conductive composite [25,26].…”