Sensitive and Selective Electrochemical Analysis of Methyl‐parathion (MPT) and 4‐Nitrophenol (PNP) by a New Type p‐NiTSPc/p‐PPD Coated Carbon Fiber Microelectrode (CFME)

Abstract

AbstractA novel modified carbon fiber microelectrode (CFME) was obtained by combination of tetrasulfonated nickel phtalocyanine (p‐NiTSPc) electroformed film associated to para‐phenylenediamine (p‐PPD) electropolymerized outer‐coating. The modified CFMEs where denoted C/p‐NiTSPc and C/p‐NiTSPc/p‐PPD, respectively. These electrodes are dedicated to the organophosphates compounds (OPs) methyl‐parathion (MPT) and para‐nitrophenol (PNP). Our contribution shows that both OPs can be determined simultaneously on the unmodified and modified C/p‐NiTSPc CFMEs. A clear electrocatalytic activity towards both MPT and PNP redox process was observed, for the first time, in presence of p‐NiTSPc. The obtained sensitivity for the C/p‐NiTSPc CFME was 80 nA L mg−1 in the concentration range 0.01 to 10 mg/L with a detection limit of 40 μg/L. Also the combination of p‐NiTSPc and p‐PPD electrodeposited films show, for the first time, the possibility to discriminate on the C/p‐NiTSPc/p‐PPD CFME between MPT and PNP. Stability experiments were also conducted for 3 weeks in acetate buffer showing a good reproductibility of the sensitivity to PNP vs. time in presence of MPT with a little loss of sensitivity (5%) after 3 weeks.