Voltammetric detection of chlorite ion using carbon paste sensor modified with N-cetylpyridinium-bentonite

摘要

A voltammetric carbon paste sensor (CPS) was described for the detection of chlorite ion in water analysis. For the construction of the voltammetric CPS, organo-bentonites were synthesised by intercalation of N-cetylpyridinium (NCP) at different amounts into interlayer gap of bentonite. Some features of the obtained organo-bentonites such as structural, thermal and morphological were investigated by using various techniques. Afterwards, the voltammetric behaviour of the solution was investigated with cyclic voltammetry in the potential range of 0.0-1.0V at a scan rate of 50mVs(-1) based on the obtained organo-bentonites as electroactive material. The characterisation of the prepared organo-bentonites as electroactive material, the effect of the amount of NCP-bentonite (NCP-B) in modified CPS on the 10.0mM response was tested by chancing the percentage of NCP-B in the range of 2.50-12.50% under identical experimental conditions. The pH of the measurement cell was optimised by using 0.04M Britton-Robinson buffer in the range of pH 2.0-12.0. Under the optimised conditions, developed sensor exhibited a linear response in the range of 2.0x10(-5) to 2.0x10(-4)M chlorite ions concentrations. The detection limit and the limit of quantification were figured out as 6.0x10(-6) and 2.0x10(-5)M, respectively. The repeatability and reproducibility of the sensor were calculated as 5.0% and 6.8% (N=5), respectively. Finally, the sensor was successfully applied for the analysis of bottled water, and the mean recovery was found as 103 +/- 3%.