Novel Thallium(III) Solid‐Contact Ion‐Selective Electrode with Electropolymerized Transducer

Abstract

A solid-contact ion-selective electrode for thallium(III) based on its complex with new complexone N,N'-) into a polymeric membrane is described. The ion-to-electron transducer used as the solid contact electrode was polyaniline which was electrochemically polymerized on a Pt wire. The plasticized poly(vinyl chloride) membrane incorporate ion-associate of [Tl(DOEDDSA)] À with N,N,N-trihexadecyl-N-methylammonium cation as electroactive material for ionometric sensor controls. The best performance in terms of slope (56 AE 2 mV per decade) and response time (15 s) is displayed. The sensor shows a Nernstian response for [Tl(DOEDDSA)]À ions over a wide concentration range of 6.4 Â 10 À7 to 10 À2 M, with a detection limit of thallium complexonate 8.2 Â 10 À8 M. The sensor can be used for more than three months without any considerable divergence in potentials. The selectivity is also good towards the most common univalent and divalent anions and the signal is constant in the pH range 4.7 -9.0. An application to thallium determination in a mineral sample proved to be a success, and it was employed as an indicator electrode in direct potentiometry.

Potentiometric Ion Sensors

“…Good overall analytical performance was obtained for such solid-contact ISEs selective to pH 164 and Tl 3+ . 165 The stability of the PANI solid contact in K + -ISEs based on plasticized PVC was studied by using UV-visible spectroscopy. Partial conversion of PANI from its conducting emeraldine salt form to its nonconducting emeraldine base form was found to take place during long-term measurements (1-3 months) but not during short-term measurements (4 days).…”

“…Electrosynthesized PANI was applied as a solid contact in ISEs based on plasticized PVC-based ion-selective membranes. Good overall analytical performance was obtained for such solid-contact ISEs selective to pH and Tl 3+ . The stability of the PANI solid contact in K + -ISEs based on plasticized PVC was studied by using UV−visible spectroscopy.…”

Potassium-Selective Electrodes with Stable and Geometrically Well-Defined Internal Solid Contact Based on Nanoparticles of Polyaniline and Plasticized Poly(vinyl chloride)

“…The pH stability of PANI is of crucial importance when applying PANI as a component in all-solid-state ion-selective electrodes (ISEs). Surprisingly, the stability of the solid contact (SC) layer of PANI is reported in only one study, although different types of electrochemically prepared − and soluble forms of PANI − have been applied as SC materials 15-25 and in the single-piece (SPE) configuration. − ,− No stability studies have either been carried out with the other types of most commonly used CP-based SC materials, such as poly(pyrrole), poly(3-octylthiophene) (POT), and poly(3,4-ethylenedioxythiophene) (PEDOT). In most of the studies, it is only assumed that the CP-based SCs are stable, even though it is known that time-dependent changes of the oxidation state may occur within the CP phase.…”

“…The pH stability of PANI is of crucial importance when applying PANI as a component in all-solid-state ion-selective electrodes (ISEs). Surprisingly, the stability of the solid contact (SC) layer of PANI is reported in only one study, 15 although different types of electrochemically prepared [15][16][17][18][19][20][21][22][23][24][25] and soluble forms of PANI [26][27][28][29][30][31][32][33][34] have been applied as SC materials [15][16][17][18][19][20][21][22][23][24][25] and in the single-piece (SPE) configuration. [26][27][28][30][31][32] No stability studies have either been carried out with the other types of most commonly used CP-based SC materials, such as poly(pyrrole), 35 poly(3-octylthiophene) (POT), 36 and poly(3,4-ethylenedioxythiophene) (PEDOT).…”

Developments in the Field of Conducting and Non-conducting Polymer Based Potentiometric Membrane Sensors for Ions Over the Past Decade

“…During the past decade, there were five reports on Al 3+ ion selective electrodes based on furyl (ethanedione, di-(2-furyl)), bis(5-phenylazosalicylaldehyde)-2,3-naphthalene diimine, hydroxythio-xanthones, xanthone derivative, and N,N -bis(salicylidene)-1,2-phenylenediamine (salophen) [ 185 - 189 ], two reports on Ga 3+ sensors based on clorogallium(III), 2,9-dimethyl-4,11-diphenyl-1,5,8,12-tetraaza-cyclotetradeca-1,4,8,11-tetraene (DDTCT) [ 190 , 191 ], two reports on In 3+ ISEs based on 1-benzyl-3-methyl-4-benzoyl-5-pyrazolone, 15-crown-5-dicyclohexano-18-crown-6 [ 192 , 193 ], and seven reports on Tl 3+ ion selective electrodes based on quinoline-carbonitrile calix[ 6 ]arene or calix[ 5 ]arene derivatives, 1,21,23,25-tetramethyl-2,20:3,19-dimetheno-[H,2]H,23H,25H-bis-[ 1 , 3 ]dioxocino[5,4-i:5′, 4′-i]benzo[1,2d:5.4-d']bis[ 1 , 3 ]benzodioxocin, 2′-amino-1,3,5′-trioxospiro[indane-2,4′(5′H)-3′-cyano indeno(1.2-b)]pyran, dibenzyldiaza-18-crown-6, tetrachlorothallate(III)-2,3,5-triphenyl-2-H- tetrazolium ion pair, and N′ -dioctylethylenediamine- N′ -disuccinic acid [ 194 - 200 ]. The statistical diagram of the reported potentiometric membrane sensors based on non-conducting polymer for third main group cations is shown in Figure 9 .…”