Construction of Chemically Modified Electrode for the Selective Determination of Copper(II) Ions in Polluted Water Samples Based on new β-cyclodextrine and 1,4-bis(6-bromohexyloxy)benzene Ionophores

Novel chemically modified carbon paste ion-selective electrodes (CMCPEs) for copper(II) ions determination based on beta-cyclodextrin (beta-CD) and beta-cyclodextrin/1,4-bis(6-bromohexyloxy) benzene (beta-CD/BHOB) as new ionophores have been prepared and studied. The proposed potentiometric method was based on the fabrication of modified beta-cyclodextrin-chemically modified carbon paste sensor (beta-CD-CMCPEs; electrode III) and modified beta-cyclodextrin/1,4-bis(6-bromohexyloxy) benzenechemically modified carbon paste sensor (beta-CD/BHOB-CMCPEs; electrode VI) sensors. CMCPEs have been successfully used for the potentiometric titration of Cu(II) in the analytical grad solutions, with a potential jump amounts to 125 and 214 mV for electrode (III) and electrode (VI), respectively. These sensors have wide linear dynamic range from 3.1 x 10(-7) -1 x 10(-2) and 1 x 10(-7) -1 x 10(-2) mol L-1 with a Nernstian slope of 28.90 +/- 0.92 and 29.94 +/- 0.12 mV decade-1 and low detection limit of 3.1 x 10(-7) and 1 x 10(-7) mol L-1 for electrode (III) and electrode (VI), respectively. They have fast response time (9 and 6 s) and good selectivity with respect to different metal ions. beta-CD and beta-CD/BHOB based sensors were suitable for aqueous solutions of pH range from 3.5 to 7 and 3.0 to 8. They can be used for about 3 and 4 months without any considerable divergence in potential for electrode (III) and electrode (VI), respectively. The frequently used Cu(II) solution of analytical and technical grade as well as Cu(II) ion in different water samples has been successfully titrated and the results obtained agreed with those obtained with inductively coupled plasma atomic absorption spectrometry (ICP-AES).