A critical review on photochemical conversions in flow analysis.
Photochemical conversions are cost-effective and environmental friendly processes that require mild experimental conditions and avoid generation of highly acidic wastes. Treated samples are then compatible with most of the analytical techniques. These characteristics become more relevant when the photoconversions are accomplished to flow analysis, thus allowing exploitation of incomplete reactions, the effective use of the photogenerated unstable radicals and in-line sample treatment. Decreasing of reagent consumption and waste generation, sample processing in a closed environment, and improvement of efficiency of the photochemical processes are other inherent advantages. These aspects are critically reviewed in this article, which emphasizes applications to fractionation and speciation analysis, photo-induced luminescence, miniaturization, and in-line waste treatment. Design of flow-through photochemical cells, use of auxiliary reagents in homogeneous and heterogeneous media, and configurations of flow manifolds are also discussed.
Center of Natural and Human Sciences, Federal University of ABC, Avenida dos Estados, 5001, 09210-170, Santo André, SP, Brazil.
Diogo L
DL
Rocha
Luiz de Queiroz College of Agriculture, University of São Paulo, PO Box 9, 13418-970, Piracicaba, SP, Brazil.
Marcos Y
MY
Kamogawa
Center for Nuclear Energy in Agriculture, University of São Paulo, PO Box 96, 13400-970, Piracicaba, SP, Brazil. Electronic address: frprocha@cena.usp.br.
Fábio R P
FR
Rocha
Flow analysis; Photo-assisted digestion; Photochemical reactions; Reagent photogeneration; Sample treatment; Speciation