Sensors (Aug 2008)

Free Base Porphyrins as Ionophores for Heavy Metal Sensors

  • Liliana Olenic,
  • Gheorghe Mihailescu,
  • Otilia Bizerea,
  • Viorica Cosma,
  • Elena Maria Pica,
  • Eugenia Fagadar Cosma,
  • Dana Vlascici

Journal volume & issue
Vol. 8, no. 8
pp. 4995 – 5004

Abstract

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Two functionalized porphyrins: 5,10,15,20-tetrakis(3,4-dimethoxyphenyl) porphyrin (A) and 5,10,15,20-tetrakis(3-hydroxyphenyl)porphyrin (B) obtained and characterized by us were used as ionophores (I) for preparing PVC-based membrane sensors selective to Ag+, Pb2+ and Cu2+. The membranes were prepared using three different plasticizers: (bis(2-ethylhexyl)sebacate (DOS), dioctylphtalate (DOP), o-nitrophenyl octyl ether (NPOE) and potassium tetrakis(4-chlorophenyl)borate (KTClPB) as additive. The functional parameters (linear concentration range, slope and selectivity) of the sensors with membrane composition: (I:PVC:KTClPB:Plasticizer) in different ratios were investigated. The best results were obtained for the membranes in the ratio I:PVC:KTClPB:Plasticizer 10:165:5:330. The influence of pH on the sensors response was studied. The sensors were used for a period of four months and their utility has been tested on synthetic and real samples.

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