Authors: Raúl A SánchezMoreno M Jesús Gismera M Teresa Sevilla Jesús R Procopio
Publish Date: 2010/01/27
Volume: 397, Issue: 1, Pages: 331-338
Abstract
A disposable screenprinted electrode was designed and evaluated for direct detection of chromiumVI in batch and flow analysis The carbon screenprinted electrode was modified with a graphite–epoxy composite The optimal graphite–epoxy matrix contains 375 graphite powder 125 diphenylcarbohydrazide a selective compound for chromiumVI and 50 epoxy resin The principal analytical parameters of the potentiometric response in batch and flow analysis were optimized and calculated The screenprinted sensor exhibits a response time of 20 ± 1 s In flow analysis the analytical frequency of sampling is 70 injections per hour using 01 M NaNO3 solution at pH 3 as the carrier a flow rate of 25 mL·min−1 and an injection sample volume of 050 mL The sensor shows potentiometric responses that are very selective for chromiumVI ions and optimal detection limits in both static mode 21 × 10−7 M and online analysis 94 × 10−7 M The disposable potentiometric sensor was employed to determine toxicity levels of chromiumVI in mineral tap and river waters by flowinjection potentiometry and batch potentiometry ChromiumVI determination was also carried out with successful results in leachates from municipal solid waste landfills
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