Mechanism of electropolymerization of 1-naphthylamine in aqueous acid media

Arévalo, A.H.; Fernández, Héctor; Silber, Juana J.; Sereno, Leonides

doi:10.1016/0013-4686(90)90008-n

Cited by 62 publications

(36 citation statements)

References 31 publications

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“…25 The working and counter electrode compartments were separated by a fiber glass paper. The corresponding working electrode was a GC cylindrical bar, with a geometric area of 2.64 cm 2 .…”

Section: Apparatus and Experimental Measurementsmentioning

confidence: 99%

Electrochemical reduction of the mycotoxin citrinin at bare and modified with multi-walled carbon nanotubes glassy carbon electrodes in a non-aqueous reaction medium

Zachetti¹,

Granero²,

Robledo³

et al. 2012

J. Braz. Chem. Soc.

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O mecanismo de redução eletroquímica de citrinina em acetonitrila mais (C 4 H 9 ) 4 NClO 4 0,1 mol L -1 tanto em eletrodo de carbono vítreo (GC) não modificado quanto em eletrodo GC modificado com nanotubos de carbono de paredes múltiplas foi investigado por voltametria cíclica e eletrólise a potencial controlado. Os resultados obtidos permitiram inferir um mecanismo de eletroredução complexo com etapas químicas e eletroquímicas, acopladas à reação inicial de transferência de elétron. Citrinina apresentou pico catódico único que corresponde no mínimo a duas etapas de redução envolvendo um elétron e duas reações químicas homogêneas, segundo mecanismo de autoprotonação do tipo ECEC (transferência de elétron acoplada com aceitação de próton). As reações químicas se originam nas transferências de próton intermolecular do substrato para os seus produtos intermédios básicos de redução, caracterizando um mecanismo de autoprotonação. Análise cinética por procedimentos de simulação de resultados voltamétricos permitiu uma caracterização completa do mecanismo de redução heterogêneo de citrinina.Electrochemical reduction mechanism of citrinin in acetonitrile plus 0.1 mol L -1 (C 4 H 9 ) 4 NClO 4 at both bare and modified with multi-walled carbon nanotube glassy carbon (GC) electrodes was investigated by cyclic voltammetry and controlled potential electrolysis. Results allowed to infer a complex electroreduction mechanism with chemical and electrochemical steps coupled to the initial electron transfer reaction. Citrinin shows a single cathodic peak that corresponds at least to two electron reduction steps and two homogeneous chemical reactions, conforming to an ECEC (electron-transfer coupled with proton acceptance) self-protonation mechanism. The chemical reactions are originated in the intermolecular proton transfers from the substrate to its basic reduction intermediates, featuring a self-protonation mechanism. Kinetics analysis by simulation procedures of voltammetric results permitted a fully characterization of the mechanism of citrinin heterogeneous reduction.Keywords: citrinin, mycotoxins, multi-walled carbon nanotubes, cyclic voltammetry, square wave voltammetry IntroductionMycotoxins are a group of secondary metabolites produced by fungi of different species and have different structural characteristics. 1 Some mycotoxins are carcinogenic, others are immunosuppressive, vasoactive and others can cause central nervous system damage. Sometimes, the same mycotoxin can cause more than one type of toxic effect. 1 Citrinin or (3R, 4S)-4,6-dihydro-8-hydroxi-3,4,5-trimethyl-6-oxo-3H-2-benzopyran-7-carboxylic acid (CITH, Figure 1) was first isolated from filamentous fungus Penicillium citrinum. 2 It is also produced by other species of Penicillium, 3 Aspergillus 4 and Monascus. 5 Electrochemical Reduction of the Mycotoxin Citrinin at Bare and Modified J. Braz. Chem. Soc. 1132 CITH crystallizes in a disordered structure, with both p-quinone and o-quinone tautomeric forms in a dynamic equilibrium in the solid state (Figur...

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“…25 The working and counter electrode compartments were separated by a fiber glass paper. The corresponding working electrode was a GC cylindrical bar, with a geometric area of 2.64 cm 2 .…”

Section: Apparatus and Experimental Measurementsmentioning

confidence: 99%

Electrochemical reduction of the mycotoxin citrinin at bare and modified with multi-walled carbon nanotubes glassy carbon electrodes in a non-aqueous reaction medium

Zachetti¹,

Granero²,

Robledo³

et al. 2012

J. Braz. Chem. Soc.

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“…A com pen sat ing po lar planimeter (In ter na tional Trade As soci ates, Ja pan) was used for this pur pose. In each case, the ap pro pri ate back ground cur rent val ues were sub tracted 6 . Sim i lar re sults are ob tained if the sig nal is pro cessed dig itally, us ing the cor re spond ing EG&G PAR soft ware, however in this case the sig nal is much noiser than in the an a log i cal one.…”

Section: Ap Pa Ra Tusmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

“…Pre vi ous stud ies show that when ar o matic amines such as naphtidine 5 , 1-naphtylamine 6 , and benzidine (Bz) 7 are electrooxidized, they fol low a com plex re ac tion to give a poly mer that ad heres to the elec trode sur face. These polymers which ad here to a base metal are con duc tors, and their dop ing grade can be con trolled 9,11,12 .…”

Section: Introductionmentioning

confidence: 99%

“…Methods that have been used for elec trode mod i fi ca tion in clude phys i cal coat ing, co va lent at tach ment and electropolymerization. Par tic u larly, electropolymerization of fers an ef fec tive and ver sa tile way to de posit poly mer film on a sub strate elec trode [5][6][7][8] .The electrooxidation of ar o matic amines is well known, and dif fer ent as pects of their mech a nism have been elu cidated 9,10 . Pre vi ous stud ies show that when ar o matic amines such as naphtidine 5 , 1-naphtylamine 6 , and benzidine (Bz) 7 are electrooxidized, they fol low a com plex re ac tion to give a poly mer that ad heres to the elec trode sur face.…”

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Incorporation and voltammetric determination of silver (I) at an electrode electrochemically modified with a poly-benzidine film

D’Eramo

Arévalo

Silber

et al. 1997

J. Braz. Chem. Soc.

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Eletrodos modificados com filmes de poli-bendizina são quimicamente estáveis no intervalo de pH en tre 0 e 7 e podem ser ciclados de -0.200 a 0.850 V sem evidência de decomposição. Conseqüentemente, neste intervalo de potencial, eles podem ser usados como ma te rial eletródico para a oxidação ou redução de diferentes espécies. Uma propriedade interessante deste eletrodo modificado é sua capacidade de capturar e quantificar o íon Ag(I) presente na solução. Para obter resultados reproduzíveis a etapa de acumulação foi realizada numa solução de AgNO 3 com um tampão de acetato de pH = 7. Após redução para Ag(0) na mesma solução, a etapa de determinação foi executado por voltametria cíclica. A resposta analítica corresponde à oxidação para Ag(I) e a quantia de prata incorporada ao filme foi determinada a partir da carga do pico anódico. O uso potencial deste método para a determinação analítica da prata é discutido.Elec trodes mod i fied with poly-benzidine films are chem i cally sta ble in the pH range between 0 and 7, and can be cy cled from -0.200 to 0.850 V with no ev i dence of de com po si tion. Con se quently, in this po ten tial range, they can be used as elec trode ma te rial for ox i da ti on or reduc tion of dif fer ent spe cies. One in ter est ing prop erty of this mod i fied elec trode is its ca pac ity to cap ture and quan tify Ag(I) ion pres ent in so lu tion. To ob tain re pro duc ible re sults, th e ac cumu la tion step was car ried out in a AgNO 3 so lu tion with ac e tate buffer at pH = 7. Af ter re duc tion to Ag(0) in the same so lu tion, the de ter mi na tion step was per formed by cy clic voltammetry. The an a lyt i cal re sponse cor re sponds to sil ver ox i da tion to Ag(I), and the amount of sil ver incor po rated into the film was de ter mined from the charge of the an odic peak. The po ten tial us e of this method for an a lyt i cal de ter mi na tion of sil ver is dis cussed. Key words: mod i fied elec trodes, poly-benzidine, electroanalysis, sil ver(I) In tro duc tionIn the con text of metal ion anal y ses, chem i cally mod ified elec trodes (CMEs) pos sess ing prop er ties have emerged as one of the most at trac tive ar eas for re search 1-4 . Among their ad van tages are their in her ent high se lec tiv ity and sen si tiv ity. Methods that have been used for elec trode mod i fi ca tion in clude phys i cal coat ing, co va lent at tach ment and electropolymerization. Par tic u larly, electropolymerization of fers an ef fec tive and ver sa tile way to de posit poly mer film on a sub strate elec trode [5][6][7][8] .The electrooxidation of ar o matic amines is well known, and dif fer ent as pects of their mech a nism have been elu cidated 9,10 . Pre vi ous stud ies show that when ar o matic amines such as naphtidine 5 , 1-naphtylamine 6 , and benzidine (Bz) 7 are electrooxidized, they fol low a com plex re ac tion to give a poly mer that ad heres to the elec trode sur face. These polymers which ad here to a base metal are con duc tors, and their dop ing grade can be con trolled 9,11,12 .Re c...

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HPLC Analysis of Carbohydrates with Electrochemical Detection at a Poly-1-naphthylamine/Copper Modified Electrode

D’Eramo¹,

Marioli²,

Arévalo³

et al. 1999

Electroanalysis

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Carbohydrates are detected by constant potential amperometric detection at a modi®ed electrode consisting of poly-1-naphthylamine coated glassy carbon with copper ions incorporated into the polymeric matrix. The polymer is electrodeposited onto the glassy carbon surface by cyclic voltammetric experiments, and copper ions incorporated by immersion of the modi®ed electrode in a 0.10 M cupric ions solution. The amount of copper incorporated into the polymeric matrix is regulated by controlling the immersion time. Cyclic voltammetric experiments showed that glucose was oxidized at the modi®ed electrode surface. The catalytic current for glucose oxidation was dependent on the amount of copper incorporated. Flow injection experiments allowed the determination of the working electrode potential at which maximum signal-to-noise ratios were obtained. The electrode was successfully used in the high performance liquid chromatographic analysis of various carbohydrates.

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Mechanism of electropolymerization of 1-naphthylamine in aqueous acid media

Cited by 62 publications

References 31 publications

Electrochemical reduction of the mycotoxin citrinin at bare and modified with multi-walled carbon nanotubes glassy carbon electrodes in a non-aqueous reaction medium

Electrochemical reduction of the mycotoxin citrinin at bare and modified with multi-walled carbon nanotubes glassy carbon electrodes in a non-aqueous reaction medium

Incorporation and voltammetric determination of silver (I) at an electrode electrochemically modified with a poly-benzidine film

HPLC Analysis of Carbohydrates with Electrochemical Detection at a Poly-1-naphthylamine/Copper Modified Electrode

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