title: Monitoring of carboxylic carbon nanotubes in surface water by using multiwalled carbon nanotube-modified filter as preconcentration unit.
abstract: In this paper, for the first time, the possibility of preconcentrating and determining carboxylic single-walled carbon nanotubes (c-SWNTs) from environmental water samples is demonstrated. The method is based on the preconcentration of c-SWNTs and their further electrophoretic analysis. The preconcentration of c-SWNTs has been successfully performed on a filter modified with multiwalled carbon nanotubes (MWNTs), which allows the use of high preconcentration rates. MWNT-modified filters were fabricated in the laboratory from a surfactant dispersion of MWNTs. The main variables affecting the preconcentration of analytes are studied and discussed in the paper. Electrophoretic separation of carboxylic SWNTs was accomplished by using a 50 mM ammonium acetate solution at pH 7.5 as a background electrolyte and a potential of 15 kV. Under these conditions, separation was completed within only 5 min. Recoveries for the analysis of spiked samples ranged from 70 to 85% and the precision from 6.4 to 7.3%.
authors.affiliation: Department of Analytical Chemistry, Campus de Rabanales, University of Cordoba, E-14071 Cordoba, Spain.
authors.forename: Beatriz
authors.initials: B
authors.lastname: Suárez
authors.forename: Yolanda
authors.initials: Y
authors.lastname: Moliner-Martínez
authors.forename: Soledad
authors.initials: S
authors.lastname: Cárdenas
authors.forename: Bartolomé M
authors.initials: BM
authors.lastname: Simonet
authors.forename: Miguel
authors.initials: M
authors.lastname: Valcárcel