Multicommutation as an environmentally friendly analytical tool in the hydride generation atomic fluorescence determination of tellurium in milk
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The aim of this study is to show the advantages of the emerging multicommutation methodology based on the use of solenoid valves for Te determination in milk by hydride generation atomic fluorescence spectrometry (HG-AFS). The delivery of a series of alternating sequential insertions of small volumes of samples and reagents gives rise to new hydrodynamic processes and exciting analytical potentials by controlling the time of flow through the on/off-switched solenoid valves. This drastically reduces the reagent consumption by a factor of 4 and the generation of effluents (590 mL h−1 instead of 750 mL h−1 generated by the continuous-mode measurement) and also provides an improvement in the laboratory productivity by an increase of the sample throughput (85 h−1 compared to 20 h−1 found in the continuous mode). So, multicommutation is an environmentally and economically sustainable alternative to the methodology based on continuous measurements. The multicommutation-based method developed was applied to tellurium determination in commercially available milk samples; a calibration range of 0.0–0.5 ng mL−1 and a detection limit of 0.20 ng L−1 with average relative standard deviation of 2.1% were found. Comparable results were obtained for a series of samples using both continuous and multicommutation HG-AFS modes.
KeywordsMulticommutation Tellurium determination Atomic fluorescence spectrometry Hydride generation Milk analysis
Authors acknowledge the financial support from The Ministerio de Ciencia y Tecnología, Project n° AGL 2002–00729 and Project n° GV 99–115–1-02. E.R. also acknowledges a “V Segles” grant and P.C. acknowledges a FPU grant from The Secretaría de Estado de Educación y Universidades.