Synthesis and study of pseudostationary phase based carbon nanotubes for the separation of emerging pollutants

LANARO, VERONICA M; PERALTA CECILIA MARIANA; STEGE, PATRICIA W; SOMBRA, LORENA LUJÁN

Simposio; 23rd Latin-American Symposium on Biotechnology, Biomedical, Biopharmaceutical, and Industrial Applications of Capillary Electrophoresis and Microchip Technology (LACE).; 2017

Emerging pollutants (EPs) are defined as synthetic or naturally occurring chemicals that are not commonly monitored but which have the potential to enter the environment and cause adverse ecological and (or) human health effects [1]. Therefore, continuous efforts are devoted to develop appropriate methods for their monitoring and quantification in environmental samples.Electrokinetic chromatography (EKC) has become a widely accepted technique forelectrophoresis-driven separations. The use of a pseudostationary phase (PSP) in EKC benefits by not requiring packing or frits. PSPs have the advantage of introducing a novel interaction phase for the analytes, which greatly simplifies capillary exchange and circumvents contamination inherent with complex mixtures. The aim of this study was to develop a methodology to separate a mixture of emerging pollutants (pharmaceuticals in this case). The studied drugs were paracetamol, naproxen, piroxicam, ketorolac, trimethoprim, sulfamethoxazole, cephalexin and amoxicillin.We performed an EKC methodology adding carboxylic multi-walled carbon nanotubes (c- MWNT) to the BGE to generate a pseudo stationary phase PSP system. To reduce the sedimentation of c-MWNTs phenomenon we studied the addition of different additives into the BGE. The best results were obtained using ethylene glycol.A Beckman P/ACE MDQ instrument (Beckman Instruments, Fullerton, CA, USA) equipped with a diode array detector and a data handling system with an IBM PC and P/ACE System MDQ Software was used.The results showed that the interactions between the analytes and the MWNTs resulted in an increase of the migration time. We were unable to achieve a good separation of the analytes without the pseudophase. Under the optimum conditions (20 mM sodium tetraborate, pH=9,2, c-MWNTs 2 %, voltage applied 12 kV, UV detection 190 nm) the drugs were separated in less than 25 min.The potential of the EKC method was shown performing the analysis of water samples spiked with the studied compounds. As preliminary conclusions, we demonstrated the applicability of the EKC methodology for monitoring and quantification of emerging pollutants in water samples.Reference:1. Geissen V, Mol H, Klumpp E, Umlauf G, Nadal M, van der Ploeg M, van de Zee S, Ritsema C. Int. Soil Water Conserv. Res. 2015, 3, 57?65.