Carbon-nanotube amperometric sensor for selective determination of 4-chloroaniline in commercial chlorhexidine solutions

• Published in: Sensors and actuators. B, Chemical Chemical, 2016-08, Vol.231, p.38-44
• Main Authors: Montes, Rodrigo H.O., Lima, Ana P., dos Santos, Vagner B., Vidal, Denis T.R., do Lago, Claudimir L., Richter, Eduardo M., Munoz, Rodrigo A.A.
• Format: Article
• Language: English
• Subjects: Actuators; Capillarity; Chlorhexidine; Chlorhexidine digluconate; Degradation product; Electrical measurements; Electrodes; Mass spectrometry; Mouth rinse; Multi wall carbon nanotubes; Multi-walled carbon nanotube; Sensors
• ISSN: 0925-4005; 1873-3077
• DOI: 10.1016/j.snb.2016.02.139

[Display omitted] This work reports a carbon-nanotube amperometric sensor for the selective determination of 4-chloroaniline (4-CLA), the major degradation product found in commercial chlorhexidine solutions. The harmful 4-CLA is detected on a multi-walled carbon nanotube (MWCNT)-modified electrode, free from the interference of chlorhexidine and other substances present in such samples, with a detection limit of 50nmolL−1. MWCNTs of two different dimensions were evaluated for 4-CLA detection and a 3-fold increase in sensitivity using both modified electrodes was obtained in comparison with the bare electrode. The association of batch-injection analysis with the amperometric detection provided high precision (1.2%) and sample throughput (130h−1). Analyses of samples by capillary electrophoresis-tandem mass spectrometry (CE-MS/MS) attested the accuracy of the proposed method. Mouth rinse and skin disinfectant samples presented 4-CLA concentrations in the range between 4 and 235μmolL−1.