Chemically surface-modified carbon nanoparticle carrier for phenolic pollutants: Extraction and electrochemical determination of benzophenone-3 and triclosan.
Chemically surface-modified (tosyl-functionalized) carbon nanoparticles (Emperor 2000 from Cabot Corp.) are employed for the extraction and electrochemical determination of phenolic impurities such as benzophenone-3 (2-hydroxy-4-methoxybenzophenone) or triclosan (5-chloro-2-(2,4-dichlorophenoxy)phenol). The hydrophilic carbon nanoparticles are readily suspended and separated by centrifugation prior to deposition onto suitable electrode surfaces and voltammetric analysis. Voltammetric peaks provide concentration information over a 10-100microM range and an estimated limit of detection of ca. 10microM (or 2.3ppm) for benzophenone-3 and ca. 20microM (or 5.8ppm) for triclosan. Alternatively, analyte-free carbon nanoparticles immobilized at a graphite or glassy carbon electrode surface and directly immersed in analyte solution bind benzophenone-3 and triclosan (both with an estimated Langmuirian binding constants of K approximately 6000mol(-1)dm(3) at pH 9.5) and they also give characteristic voltammetric responses (anodic for triclosan and cathodic for benzophenone-3) with a linear range of ca. 1-120microM. The estimated limit of detection is improved to ca.5microM (or 1.2ppm) for benzophenone-3 and ca. 10microM (or 2.3ppm) for triclosan. Surface functionalization is discussed as the key to further improvements in extraction and detection efficiency.
Vidal
Lorena
L
Departamento de Química Analítica, Nutrición y Bromatología, Universidad de Alicante, P.O. Box 99, E-03080, Alicante, Spain.
Chisvert
Alberto
A
Canals
Antonio
A
Psillakis
Elefteria
E
Lapkin
Alexei
A
Acosta
Fernando
F
Edler
Karen J
KJ
Holdaway
James A
JA
Marken
Frank
F
D001577:Benzophenones / Q000032:analysis*; D002244:Carbon / Q000737:chemistry*; D004563:Electrochemistry; D004566:Electrodes; D053758:Nanoparticles / Q000737:chemistry*; D010316:Particle Size; D012680:Sensitivity and Specificity; D013499:Surface Properties; D014260:Triclosan / Q000032:analysis*; D014873:Water Pollutants / Q000032:analysis*
D001577:Benzophenones; D014873:Water Pollutants; D014260:Triclosan; D002244:Carbon; C005290:oxybenzone