Use of factorial design and Doehlert matrix for multivariate optimisation of an on-line preconcentration system for lead determination by flame atomic absorption spectrometry

Abstract

A system for on-line preconcentration and determination of lead by flame atomic absorption spectrometry (FAAS) was proposed. It was based on the sorption of lead(II) ions on a minicolumn of polyurethane foam loaded with 2-(2-thiazolylazo)-5-dimethylaminophenol (TAM). The optimisation step was carried out using two-level full factorial and Doehlert designs for the determination of the optimum conditions for lead preconcentration. The proposed procedure allowed the determination of lead with a detection limit of 2.2 microg L(-1), and a precision, calculated as relative standard deviation (RSD), of 2.4 and 6.8 for a lead concentration of 50.0 and 10.0 microg L(-1), respectively. A preconcentration factor of 45 and a sampling frequency of 27 samples per hour were obtained. The recovery achieved for lead determination in the presence of several cations demonstrated that this procedure has enough selectivity for analysis of environmental samples. The validation was carried out by analysis of certified reference material. This procedure was applied to lead determination in natural food.

Application of two-level full factorial design and response surface methodology in the optimization of inductively coupled plasma-optical emission spectrometry (ICPOES) instrumental parameters for the determination of platinum

“…The basic idea is to change all the factors simultaneously over a set of planned experiments and then connect and interpret the results using mathematical models. The goals of experimental design are: (a) identifying the factors that have the largest effect on the system, (b) quantifying the effects of these factors and their interactions, and (c) finding the optimum values or conditions for these factors (optimization) (Harvey, 2000;Ferreira et al, 2002Ferreira et al, , 2003Bruns et al, 2006;Bingol and Kuku, 2011;Candioti et al, 2014).…”

“…Several experimental designs have been developed for example, the full factorial design (FFD) (Harvey, 2000;Ferreira et al, 2003;), the Plackett-Burman design (PBD) (Tyssedal, 2008;Deng and Tang, 1999), the BoxBehnken design (BBD) (Delacroix and Porte, 1996), and the D-optimal design (DOD) (Mantre et al, 1997;Titterington, 1975;de Aguiar et al, 1995;Mitchell, 1974;Hill, 1980). In this paper the optimization of the ICP-OES parameters are reported for the determination of platinum using the 2-Level full factorial experimental design, in conjunction with response surfaces.…”

“…Simplex optimization is a sequential procedure based on a k-factor first-order model. The response function can however not be obtained using this approach (Ferreira et al, 2003). The use of RSM enables the determination, not only the influence of the factors, but the response function as well.…”

Adsorption of blue copper on a natural and electrochemically treated bentonite

“…The equations expressing the variation of the dye uptake amount versus the operating factors (pH, contact time, clay dose and temperature) for both sorbents were established by adopting the following polynomial model, which was successfully applied in various studies (e.g., Ferreira et al 2003;Khalfaoui et al 2006;Liu et al 2004):…”

Avaliação da reação foto-fenton na decomposição de resíduos de carrapaticida

“…De maneira geral, durante a reação foto- O planejamento fatorial é uma importante ferramenta estatísti-ca e seu uso é importante na química analítica para diferentes amostras e propósitos [12][13][14][15] , pois possibilita a visualização das possíveis interações entre as variáveis selecionadas, considerando todos os parâmetros experimentais envolvidos.…”