Environmentally friendly analytical chemistry through automation: comparative study of strategies for carbaryl determination with p-aminophenol Original Research Article

A flow system, based on multicommutation and binary sampling, has been developed for improving the automated spectrophotometric determination of carbaryl with p-aminophenol (PAP) in order to reduce the waste volume and to preserve the maximum analytical performance. The procedure, which was implemented employing a flow network obtained by nesting five, three-way solenoid valves controlled by means of a 386 microcomputer equipped with an electronic interface running software written in quick basic 4.5, provides a limit of detection of 26 μg l−1, comparable to that obtained using a conventional flow injection (FIA) manifold and lower than that found by sequential injection analysis (SIA), but generating a total waste volume per sample of 1.7 ml comparable to that found in SIA and 6 times lower than that obtained by conventional FIA.