Spectrophotometric determination of carbaryl by on-line elution after its preconcentration onto polyurethane foam.
An analytical methodology has been developed for the UV-spectrophotometric determination of carbaryl in waters after its preconcentration onto a polyether type polyurethane foam followed by on-line elution. The aforementioned strategy offers an easy way for in-field sampling and to improve the analytical sensitivity. Several chemical and flow variables (mass of sorbent, sample flow rate, sample volume and carrier flow rate) were studied to ensure the best performance of the system. Recovery studies, carried out on natural water samples spiked with known amounts of carbaryl at concentration levels between 250 and 500 mug l(-1), provided recovery percentages between 94 and 105%. A detection limit of 12 mug l(-1) was achieved and a variation coefficient of 3.4% was obtained at 0.50 mug ml(-1).
Jorgensen Cassella
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Departamento de Geoquimica, Universidade Federal Fluminense, Niteroi/RJ, 24020-007, Brazil; Escola Tecnica Federal de Quimica/RJ, Rua Senador Furtado 21-25, Rio de Janeiro, 20270-021, Brazil.
Garrigues
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Santelli
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de la Guardia
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