Measurement of concentration profiles inside a nitrite ion-selective electrode membrane

Li, Xizhong.; Harrison, David

doi:10.1021/ac00019a018

Cited by 78 publications

(32 citation statements)

References 46 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…12 Metalloporphyrins, which are one carbon larger but structurally analogous to the cobyrinate ring of vitamin B 12 , also exhibit unique anion ionophore properties when incorporated into plasticized polymer membranes. Mn(III) [13][14][15][16][17][18][19][20] , Co(III) 13,16,[21][22][23][24][25][26] , Ru(II) 16 , and Sn(IV) 25,27-29 porphyrin-based ISEs have been shown to exhibit useful selectivity for thiocyanate, nitrite/thiocyanate, thiocyanate, and salicylate, respectively. More recently, the nature of the ionophore-anion interaction mechanism has been correlated to the charge of the central metal ion.…”

mentioning

confidence: 99%

Response Characteristics of Anion-Selective Polymer Membrane Electrodes Based on Gallium(III), Indium(III) and Thallium(III) Porphyrins

1998

View full text Add to dashboard Cite

With the evolution of ion-selective ionophore-based liquid/polymer membrane electrodes (ISEs) over the past 25 years, many cations of physiological and industrial significance can be measured effectively by direct potentiometry. However, there is a noticeable lack of analogous electrodes for many common anions. 1 Although commercial electrodes based on anionexchangers such as quaternary ammonium salts can be analytically useful, their selectivity patterns are always correlated solely with anion lipophilicity, resulting in the classical Hofmeister series (ClO 4 ->SCN -> salicyl a t eTherefore, highly hydrated anions such as fluoride, bicarbonate, chloride, and nitrite are difficult to monitor due to significant interference from more lipophilic anion species that may be present in the sample. Recently, examination of a variety of compounds that have strong yet reversible interactions with target anions has resulted in new ionophores with decidedly non-Hofmeister selectivity toward anions. 3,4 Many research groups are studying a wide variety of new ionophores that demonstrate these characteristics such as mercury 5 , silver 6 , and tin 7 organometallic compounds, fluorinated (poly)ethers 8 , metallophthalocyanines 9 , metallocenes 10 , and trifluoroacetyl derivatives. 11 The pioneering work of Simon et al., in which the behavior of lipophilic vitamin B 12 derivatives as ionophores was examined, led to one of the first nitrite selective liquid/polymer membrane electrodes. 12 Metalloporphyrins, which are one carbon larger but structurally analogous to the cobyrinate ring of vitamin B 12 , also exhibit unique anion ionophore properties when incorporated into plasticized polymer membranes. Mn(III) [13][14][15][16][17][18][19][20] , Co(III) 13,16,[21][22][23][24][25][26] , Ru(II) 16 , and Sn(IV) 25,27-29 porphyrin-based ISEs have been shown to exhibit useful selectivity for thiocyanate, nitrite/thiocyanate, thiocyanate, and salicylate, respectively. More recently, the nature of the ionophore-anion interaction mechanism has been correlated to the charge of the central metal ion.25 Metal(II) porphyrins were found to serve as neutral carriers, metal(IV) as charged carriers and metal(III) porphyrins as either neutral or charged depending on the existance and number of bound axial ligands. The use of lipophilic ionic additives, either cationic (quaternary ammonium salts for neutral carriers) or anionic (tetraphenylborate salts for charged carriers) can help to determine the dominant mechanism within the polymer membrane responsible for EMF response. 30 These ionic sites have also been found to improve general electrode performance by reducing the membrane resistance, decreasing counter-ion interference, and enhancing selectivity. 25,[30][31][32] In this work, porphyrins containing group XIII ions as metal centers are examined as unique ionophores in the preparation of anion ISEs. Electrodes based on indium(III) porphyrins in poly(vinyl chloride) (PVC) membranes have been shown previously to exhibit enhanced responses toward...

show abstract

mentioning

confidence: 99%

Response Characteristics of Anion-Selective Polymer Membrane Electrodes Based on Gallium(III), Indium(III) and Thallium(III) Porphyrins

1998

View full text Add to dashboard Cite

show abstract

“…The mass ratio of the membrane components was of 24.75 : 74.25 : 1 (PVC : plasticizer : porphyrynate). The membranes were prepared as described elsewhere [14].…”

Section: Methodsmentioning

confidence: 99%

Influence of the Co(III) porphyrinates structure on the electrochemical and sorption properties of the ion-selective membranes based on them

2015

View full text Add to dashboard Cite

Abstract-The influence of the electronic and steric effects of the p-OCH 3 , p-Cl, and o-NHCOC(CH 3 ) 3 substituents in the phenyl rings of Co(III) tetraphenylporphyrinates as well as that of the introduction of the axial nitrogen-containing ligand (dodecylimidazole) on the anionic selectivity of the membranes has been studied. It has been stated that the substitution at the phenyl cycles of the porphyrin had no significant influence on the anionic selectivity of the membrane, whereas the introduction of the axial nitrogen-containing ligand reduced the membrane specificity, the selectivity series approaching the classical Hofmeister series. All the studied electrodes have exhibited the enhanced (as compared to the Hofmeister series) selectivity towards nitrite, hydrocarbonate, and hydrophosphate anions.Keywords: porphyrinate, cobalt, axial ligand, ion-selective electrode, selectivity, sorption Development of ions-selective electrodes has been currently directed mainly on the detailed investigation of the selectivity and mechanism of the electrode reactions in order to extend the range of the practical application of ion-selective electrodes in the clinical practice and environmental studies.Various anion-exchangers (salts of quaternary ammonium, phosphonium, and arsonium bases, triphenylmethane dyes, and phenanthroline metal complexes) serve as the membrane-active component of the anion-selective electrodes. The selectivity of membranes based on the quaternary ammonium salts is determined by the solvation energy of the corresponding anions, the latter being arranged in the Hofmeister series according to this parameter [1]:2-> HPO 4 2-.The selectivity with respect to anions can be altered as compared to the Hofmeister series in the case of the selective interactions of the active membrane components with dissolved anions. Examples of such selectivity modifiers include certain lipophilic derivatives of В 12 vitamin and the structurally similar metal porphyrinates [2-6], the latter being of undoubtful interest for development of ion-selective membranes [7][8][9][10].Upon formation of metal complexes with synthetic porphyrins, the metal ion is inserted in the cavity of the macrocyclic ligand and is strongly bound to the donor atoms of the latter. The porphyrinates properties are largely determined by the incorporation of the metal ion into the conjugated electronic system of the macrocycle and the possibility of interaction with additional axial ligands.In this work we pioneered in study of the membranes containing the electrode-active thiocyanate salts of Co(III) porphyrinates. For the sake of comparison, we included the complex 1 based on mesotetraphenylporphin into consideration (The Hammett constant of the substituents in the phenyl ring σ H ≡ 0); the effect of the substitution at the phenyl groups were studied using the complexes of meso-tetra(p-methoxyphenyl)porphin 2 (σ p-OMe -0.25), meso-tetra(p-chlorophenyl)porphin 3 (σ p-Cl 0.23), and meso-tetra(o-pivalamidophenyl)porphin 4. Compounds 5 and 6 were similar ...

show abstract

“…It has been always assumed that these membranes are uniformly hydrophobic. In another key development it has been established that water penetrates into these membranes and forms a concentration gradient just inside the polymer/ solution interface [14,15]. This finding has set the practical limits on the minimum optimal thickness of ion-selective membranes on ISFETS.…”

Section: Ion Sensitive Field-effect Transitorsmentioning

confidence: 99%

Thirty Years of CHEMFETs – A Personal View

Janata

2004

Electroanalysis

View full text Add to dashboard Cite

Measurement of concentration profiles inside a nitrite ion-selective electrode membrane

Cited by 78 publications

References 46 publications

Response Characteristics of Anion-Selective Polymer Membrane Electrodes Based on Gallium(III), Indium(III) and Thallium(III) Porphyrins

Response Characteristics of Anion-Selective Polymer Membrane Electrodes Based on Gallium(III), Indium(III) and Thallium(III) Porphyrins

Influence of the Co(III) porphyrinates structure on the electrochemical and sorption properties of the ion-selective membranes based on them

Thirty Years of CHEMFETs – A Personal View

Contact Info

Product

Resources

About