Application of chemically modified multiwalled carbon nanotubes with a new Schiff base as a carrier for construction of new Cu2+ ion selective carbon paste electrode

In this research multiwalled carbon nanotubes surface chemically (MWCNT) was modified by a couple reactions between trimethoxysilylpropylamine (TMSPA) and 2-hydroxybenzaldehyde (2-HBA) and characterized by FT-IR technique. This new material (MWCNT-SPIMP) in carbon paste electrode matrices selectively the Cu2+ ion. The influences of variables including sodium tetraphenylborate (NaTPB), amount of MWCNT-SPIMP, Nujol and graphite powder on electrode response has been investigated and their value was set as graphite powder: NaTPB: Nujol: carrier in the mass (mg) ratio of 150/7.0/30/50. At the optimum value set as above the proposed Cu3+ selective electrode response is linear over the wide range concentration of 1.0 × 10-8 to 1.0 × 10-3 mol L-1 with slope of 30.01 mV per decade-1 of Cu2+ ion concentration with detection limit of 8.8 × 10-9 mol L-1. The electrode response is independent of pH in the range of 3.0-6.0 with a short the response time of about 5s. The potentiometric selectivity coefficients and selectivity sequence of proposed Cu2+ ion selective electrode has been evaluated using fixed interference method (FIM), separation solution method (SSM) and matched potential method (MPM). The proposed electrode successfully has been applied for potentiometric determination of Cu3+ ion content in various real samples and as indicator electrode for potentiometric titration of EDTA.

Keywords:

Cu2+-selective electrode , Potentiometric sensor , Carbon paste electrode , Multiwalled Carbon Nanotubes