We report the benefit of using an optimized composite electrode, based on a multiwall carbon nanotubes and epoxy resin, as working electrode in an automated flow system. The optimal composite electrode composition consists in a 10% carbon nanotubes and 90% epoxy resin. This composition provides lower limit of detection and increases the stability and reproducibility of the analytical signal compared to the 20% conventional composition electrodes. Moreover, the standard solutions are on-line prepared with an automated flow system. The integration of the developed carbon nanotube electrodes in the proposed flow system provides a highly sensitive analyzer for free chlorine determination in water down to the 20 μg L-1. The working range was found to be 0.02-4 mg L-1 with an analysis time of 60 s. The system sensitivity was maintained into the control limits (±2σ) for one month, with a mean value of -0.146 (±0.008) μA L mg-1. Validation of the analytical system has been performed by the successful determination of free chlorine in tap water and swimming pools water samples. © 2010 Elsevier B.V. All rights reserved.
|Publication status||Published - 15 Jun 2010|
- Amperometric flow system
- Carbon nanotube composite
- Chlorine analysis