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Coated capillaries with highly charged polyelectrolytes and carbonnanotubes co-aggregated with sodium dodecyl sulphate for theanalysis of sulfonylureas by capillary electrophoresis
Abstract : tSulfonylureas (SUs) are one of the most widely used herbicides to control weeds in crops. Herein,capillary electrophoresis (CE) was used to determine four sulfonylureas in natural waters, namely chlor-sulfuron (CS), iodosulfuron methyl (IM), metsulfuron methyl (MSM) and mesosulfuron methyl (MSS).First of all, a bare silica capillary was chosen with 10 mM of 1-butyl-3-methylimidazolium tetrafluoro-borate (bminBF4) as electrophoretic buffer (pH 9.6) containing 2 mg L−1of surfactant-coated single-wallcarbon nanotubes (SC-SWCNTs). A dramatic deviation in migration times was observed. Therefore, apoly(diallyldimethylammonium) chloride (PDADMAC) statically coated cationic capillary was used toimprove repeatability and to alter the selectivity of the separation. The electroosmotic flow (EOF) mea-surement revealed that the SC-SWCNTs were strongly adsorbed at the surface of the PDADMAC coatingeven in the absence of the surfactant-coated nanotubes in the electrolyte buffer. Consequently, a stablestrong cathodic EOF and excellent repeatabilities were obtained with relative standard deviations (RSDs)on migration times and on corrected peak areas below 0.9 and 1.5%, respectively. The separation of theSUs was conducted in only 6 min. No regeneration of the coating between analyses was necessary, andhigh peak efficiencies up to 173,000 theoretical plates were obtained. The bi-layer coating was subse-quently used to analyze sulfonylureas in tap water, in several mineral waters as well as in undergroundwaters spiked with SUs and directly injected into the CE capillary.
https://hal-brgm.archives-ouvertes.fr/hal-01086599
Contributeur : Anne Togola Connectez-vous pour contacter le contributeur
Soumis le : lundi 24 novembre 2014 - 15:00:35
Dernière modification le : jeudi 16 décembre 2021 - 03:56:41
Contributeur : Anne Togola Connectez-vous pour contacter le contributeur
Soumis le : lundi 24 novembre 2014 - 15:00:35
Dernière modification le : jeudi 16 décembre 2021 - 03:56:41