%0 Journal Article
%T Free Base Porphyrins as Ionophores for Heavy Metal Sensors
%A Dana Vlascici
%A Eugenia Fagadar-Cosma
%A Elena Maria Pica
%A Viorica Cosma
%A Otilia Bizerea
%A Gheorghe Mihailescu
%A Liliana Olenic
%J Sensors
%D 2008
%I MDPI AG
%R 10.3390/s8084995
%X 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.
%K Porphyrins
%K ionophores
%K sensors
%K heavy metals
%K PVC-matrix.
%U http://www.mdpi.com/1424-8220/8/8/4995