Use of tin (IV) porhyrins as Ionophores for the construction of phthalate-selective electrodes: Influence of the structure and membrane composition on their response properties

• Tipo: Artigo em Revista Científica Internacional
• Data: 2005

Autores

Santos, EMG (Autor) Outra; Araugo, AN (Autor) FFUP; Couto, CMCM (Autor) Outra; Montenegro, MCBSM (Autor) FFUP

Revista

Título: Electroanalysis

Vol. 17 Nº 14

Páginas: 1945-1951

ISSN: 1040-0397

Editora: Wiley-Blackwell

Indexação

ISI Web of Knowledge - 3 Citações

ISI Web of Science

Scopus - 3 Citações

Classificação Científica

CORDIS: Ciências da Saúde

FOS: Ciências exactas e naturais > Química

Outras Informações

ID Authenticus: P-000-0MN

DOI: 10.1002/elan.200403273

Resumo (PT): Tin(IV) porphyrins derivatives were used as ionophores for phthalate selective electrodes preparation. The influence of ionophore structure and membrane composition (amount of incorporated ionic sites) on the electrode response, selectivity and long-term stability were studied. Poly(vinyl chloride) polymeric membranes plasticized with o-NPOE (o-nitrophenyloctylether) and containing Sn(IV)-tetraphenylporphyrin (TPP) dichloride (Sn(IV)[TPP]Cl2) or Sn(IV)-octaethylporphyrin (OEP) dichloride (Sn(IV)[OEP]Cl2), and in some cases incorporating lipophilic cationic (tetraocthylammonium bromide - TOABr) and anionic (sodium tetraphenylborate - NaTPB and potassium tetrakis[3,5-bis(trifluoromethyl)phenyl]borate-KTFPB) additives, were prepared and their potentiometric characteristics compared. Both ionophores are shown to operate via a neutral mechanism, and the addition of 10 mol % of lipophilic quaternary ammonium salt derivative to the membrane is required to achieve optimal electrode performance. The potentiometric units prepared, with Sn(IV)[TPP]Cl2 (Type A) or Sn(IV)[OEP]Cl2 (Type B) without additives, presented a slope of -52.8 mV dec-1 and -58.8 mV dec-1 and LLLR of 9.9×10-5 mol L-1 and 9.9×10-6 mol L-1, respectively. The units prepared using the same metalloporphyrins and incorporating 10% mol TOABr presented a slope of -55.0 mV dec-1 and -57.8 mV dec-1 and LLLR of 5.0×10-7 mol L-1 and 3.0×10-7 mol L-1. Their analytical usefulness was assessed by potentiometric determinations of phthalate in water and industrial products providing results that presented recoveries of about 100%. Keywords <br> <br> Phthalate • Tin(IV) • Metalloporphyrins • Ion-selective electrode • Potentiometry <br> <a target="_blank" href="http://www3.interscience.wiley.com/journal/111085156/abstract"> Texto integral</a> <br> <br>

Abstract (EN): Tin(IV) porphyrins derivatives were used as ionophores for phthalate selective electrodes preparation. The influence of ionophore structure and membrane composition (amount of incorporated ionic sites) on the electrode response, selectivity and long-term stability were studied. Poly(vinyl chloride) polymeric membranes plasticized with o-NPOE (o-nitrophenyloctylether) and containing Sn(IV)-tetraphenylporphyrin (TPP) dichloride (Sn(IV)[TPP]Cl-2) or Sn(IV)-octaethylporphyrin (OEP) dichloride (Sn(IV)[OEP]Cl2), and in some cases incorporating lipophilic cationic (tetraocthylammonium bromide - TOABr) and anionic (sodium tetraphenylborate - NaTPB and potassium tetrakis[3,5-bis(trifluoromethyl) phenyl]borate-KTFPB) additives, were prepared and their potentiometric characteristics compared. Both ionophores are shown to operate via a neutral mechanism, and the addition of 10 mol % of lipophilic quaternary ammonium salt derivative to the membrane is required to achieve optimal electrode performance. The potentiometric units prepared, with Sn(IV)[TPP]Cl-2 (Type A) or Sn(IV)[OEP]Cl-2 (Type B) without additives, presented a slope of - 52.8 mV dec(-1) and - 58.8 mV dec(-1) and LLLR of 9.9 x 10(-5) mol L-1 and 9.9 x 10(-6) mol L-1, respectively. The units prepared using the same metalloporphyrins and incorporating 10% mol TOABr presented a slope of - 55.0 mV dec(-1) and - 57.8 mV dec(-1) and LLLR of 5.0 x 10(-7) mol L-1 and 3.0 x 10(-7) mol L-1. Their analytical usefulness was assessed by potentiometric determinations of phthalate in water and industrial products providing results that presented recoveries of about 100%.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 7