Application of electric fields in solid phase extraction procedures

Author(s)

Ricardo Mathias Orlando

• Document type: Doctoral Thesis
• Press: Campinas, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Instituto de Química
• Defense date: 2011-03-06

Examining board members

Susanne Rath; Emanuel Carrilho; Quezia Bezerra Cass; Carol Hollingworth Collins; Dosil Pereira de Jesus

• Advisor: Jarbas José Rodrigues Rohwedder; Susanne Rath

Abstract

Sample preparation is a crucial and determinant step for the analysis process and solid phase extraction (SPE) is a widely used technique in the preparation of complex matrices. The aim of this work was the development of devices and procedures for applying electric fields to SPE cartridges (SPE-E ®), in order to add the mechanisms of electrophoresis to the chromatographic process. For this purpose, electrodes and cartridges that allow the application of electric fields were developed, besides a system to monitor and control electrochromatographic parameters such as: flow, electric current, electric potential and temperature. By means of these devices, extractions with application of electric fields were performed using anionic, cationic and amphoteric model compounds. In order to allow a better understanding of the phenomena involved several extraction parameters were evaluated, among these: the concentration of ions in solution, pH, organic modifier, volume of washing solution and type of sorbent. The system was also evaluated for the determination of antibiotics in milk. Depending on the polarity of the electrodes used, the application of an electric field was able to modulate (accelerate or retard) the output of the model compounds from the cartridge. The extraction results obtained showed the effectiveness of the devices developed, and the immense potential of the use of electric fields in SPE to obtain better recoveries of the analytes and/or for removing interferents (AU)

• FAPESP's process: 07/07079-0 - Application of electric potentials in procedures of solid phase extration
• Grantee: Ricardo Mathias Orlando
• Support Opportunities: Scholarships in Brazil - Doctorate