Determination of crystal violet in water by direct solid phase spectrophotometry after rotating disk sorptive extraction
Author
dc.contributor.author
Manzo, Valentina
Author
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Orielle, Navarro
es_CL
Author
dc.contributor.author
Honda, Luis
es_CL
Author
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Sánchez, Karen
es_CL
Author
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Toral Ponce, María
es_CL
Author
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Richter Duk, Pablo
es_CL
Admission date
dc.date.accessioned
2014-01-28T18:55:32Z
Available date
dc.date.available
2014-01-28T18:55:32Z
Publication date
dc.date.issued
2013
Cita de ítem
dc.identifier.citation
Talanta 106 (2013) 305–308
en_US
Identifier
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DOI: 10.1016/j.talanta.2012.11.004
Identifier
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https://repositorio.uchile.cl/handle/2250/121780
General note
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Artículo de publicación ISI
en_US
Abstract
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The microextraction of crystal violet (CV) from water samples into polydimethylsiloxane (PDMS) using the rotating disk sorptive extraction (RDSE) technique was performed. The extracting device was a small Teflon disk that had an embedded miniature magnetic stirring bar and a PDMS (560 mu L) film attached to one side of the disk using double-sided tape. The extraction involves a preconcentration of CV into the PDMS, where the analyte is then directly quantified using solid phase spectrophotometry at 600 nm. Different chemical and extraction device-related variables were studied to achieve the best sensitivity for the determination. The optimum extraction was performed at pH 14 because under this condition, CV is transformed to the neutral and colorless species carbinol, which can be quantitatively transferred to the PDMS phase. Although the colorless species is the chemical form extracted in the PDMS, an intense violet coloration appeared in the phase because the -OH bond in the carbinol molecule is weakened through the formation of hydrogen bonds with the oxygen atoms of the PDMS, allowing the resonance between the three benzene rings to compensate for the charge deficit on the central carbon atom of the molecule.
The accuracy and precision of the method were evaluated in river water samples spiked with 10 and 30 mu gL(-1) of CV, yielding a relative standard deviation of 6.2% and 8.4% and a recovery of 98.4% and 99.4%, respectively. The method detection limit was 1.8 mu gL(-1) and the limit of quantification was 5.4 mu gL(-1), which can be decreased if the sample volume is increased. (C) 2012 Elsevier B.V. All rights reserved.