Flow analysis in Brazil: contributions over the last four decades

Abstract

The main contributions of Brazilian researchers to the field of flow analysis are reviewed, with an emphasis on historical developments, conceptual aspects, system design, and analytical applications. Contributions after the advent of flow injection analysis are highlighted. Novel approaches (e.g. zone merging, zone sampling, zone trapping, multi-site detection, and multi-commutation), flow modalities (e.g. monosegmented flow analysis, flow-batch analysis, multi-pumping flow analysis), as well as the pioneering implementation of different detection techniques (e.g. potentiometry, turbidimetry, flame atomic absorption spectrometry, inductively coupled plasma-optical emission spectrometry, and gravimetry) and analytical steps (e.g. titrations, membrane-less gas diffusion, and electrolytic dissolution) are highlighted. Strategies to improve analytical figures of merit and the use of the flow analyser as a tool for teaching purposes are also discussed. Contributions from Brazilian workers in the context of system miniaturization, "green" chemistry, analysis of complex samples, novel strategies and materials for in-line analyte separation/concentration, and proposals for expert systems are also highlighted. The large-scale analysis of samples of agronomical, environmental, industrial, and clinical relevance is emphasized.

Atomic spectrometry update – a review of advances in environmental analysis

“…Country-specic reviews included a description of the substantial contribution made by Brazilian researchers 204 (217 references) to the eld of ow analysis and a summary of Turkish studies 205 (146 references) that applied atomic spectrometry to investigate the uptake of potentially toxic elements by plants. None of the samples showed a marked change in As speciation over a 12 month period, but highest recoveries were always obtained following storage regime (a) and this was the only portion from which DMA could be extracted.…”

“…The Faraday array performed better for sample sizes down to 10 pg Pb, producing data 4-5 times more precise than static MICs (0.05%, 2SD, vs. 0.18-0.23% for 207 Pb/ 206 Pb). Sample sizes <10 pg were only measured in MIC mode as the 204 Pb signal was below the LOD in Faraday mode. Thus, the MIC system offered considerable promise for tracer work in the <10 pg Pb range where data with an accuracy and precision of a few percent are useful, provided blank contributions were kept below 0.1 pg.…”

“…The procedure was applicable to any double-spike system and is freely available (http:// www.isospike.org). Sample sizes <10 pg were only measured in MIC mode as the 204 Pb signal was below the LOD in Faraday mode. Thus, the MIC system offered considerable promise for tracer work in the <10 pg Pb range where data with an accuracy and precision of a few percent are useful, provided blank contributions were kept below 0.1 pg.…”

Flow Analysis: Looking Back and Forward

“…1 Brazilian researchers have effectively contributed to the inception and development of flow injection analysis (FIA), 5 the most successful approach involving unsegmented flows, and the main Brazilian contributions were critically discussed some years ago. 6 The innovations encompassed novel flow approaches (e.g., merging zones, 7 zone trapping, 8 zone sampling, 9 monosegmented flow analysis, 10 multicommutation, 11 and flow-batch analysis), 12 as well as the pioneering coupling to different detection techniques (e.g., flame atomic absorption spectrometry (FAAS), 13 inductively coupled plasma optical emission spectrometry (ICP OES), 14 turbidimetry 15 and enthalpimetry) 16 and processes (e.g., ion-exchange 17 and liquid-liquid extraction). 18 More recent advances include new alternatives for miniaturization (micro-FIA 19 and micro-flow batch analyzers), 20 exploitation of detection by digital images, 21 as well as stepwise elution in sequential injection chromatography.…”