Document Detail


Determination of herbicides in mineral and stagnant waters at ng/L levels using capillary electrophoresis and UV detection combined with solid-phase extraction and sample stacking.
MedLine Citation:
PMID:  15861801     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
In this work, the combined use of solid-phase extraction (SPE) and on-line preconcentration strategies as normal stacking mode (NSM) and stacking with matrix removal (SWMR) for the ultrasensitive and simultaneous capillary electrophoresis-ultraviolet analysis (CE-UV) of five triazolopyrimidine sulfonanilide pesticides (i.e., diclosulam, cloransulam-methyl, flumetsulam, metosulam and florasulam) in different types of water is investigated. An adequate separation electrolyte for the separation and stacking of these pesticides was obtained, considering also its compatibility with MS detection, which consisted of 24 mM formic acid and 16 mM ammonium carbonate at pH 6.4. It was observed that the use of this running buffer together with the SWMR preconcentration method provided the best results in terms of sensitivity (between 6.54 and 11.9 microg/L) and peak efficiency (up to 550000 theoretical plates per meter, NTP/m). When this on-line preconcentration procedure was combined with an off-line sample preconcentration step as SPE using C18 cartridges, the selected herbicides could be detected in the ng/L range. The optimized SPE-SWMR-CE-UV method was applied to the determination of the selected group of pesticides in spiked and non-spiked mineral and stagnant waters. Recoveries ranged between 55 and 110% and limits of detection between 131 and 342 ng/L. This work shows the great possibilities of the combined use of SPE-SWMR-CE-UV to overcome the sensitivity problems usually linked to CE analysis.
Authors:
Javier Hernández-Borges; Francisco J García-Montelongo; Alejandro Cifuentes; Miguel Angel Rodríguez-Delgado
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't; Validation Studies    
Journal Detail:
Title:  Journal of chromatography. A     Volume:  1070     ISSN:  0021-9673     ISO Abbreviation:  J Chromatogr A     Publication Date:  2005 Apr 
Date Detail:
Created Date:  2005-05-02     Completed Date:  2005-09-29     Revised Date:  2009-01-15    
Medline Journal Info:
Nlm Unique ID:  9318488     Medline TA:  J Chromatogr A     Country:  Netherlands    
Other Details:
Languages:  eng     Pagination:  171-7     Citation Subset:  IM    
Affiliation:
Department of Analytical Chemistry, Nutrition and Food Science, University of La Laguna, Avda. Astrofísico Fco. Sánchez s/n, 38071 La Laguna, Santa Cruz de Tenerife, Spain.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Electrophoresis, Capillary / methods*
Herbicides / analysis*
Reproducibility of Results
Sensitivity and Specificity
Spectrophotometry, Ultraviolet / methods*
Water Pollutants, Chemical / analysis*
Chemical
Reg. No./Substance:
0/Herbicides; 0/Water Pollutants, Chemical

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  Chiral separation of amines in subcritical fluid chromatography using polysaccharide stationary phas...
Next Document:  Approach to quasi stationary electrokinetic chromatography.