Optimization of the HS-SPME technique by using response surface methodology for evaluating chlorine disinfection by-products by GC in drinking water

Aguirre-González, Mauricio; Ocampo, Gonzalo Taborda; Lubert, Carmen Dussán; Nerín, Cristina; Rosero-Moreano, Milton

doi:10.1590/s0103-50532011001200013

Cited by 13 publications

(4 citation statements)

References 32 publications

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“…Lately, development of different sorbent materials have been the major research topic in SPME [26][27][28][29]. Materials for different analytes and sample matrices, as well as optimization of parameters affecting to the extraction, have been widely studied [30,31]. The effect of water (humidity) has been one of the studied parameters [32][33][34].…”

Section: Electronic Supplementary Materialsmentioning

confidence: 99%

Problems Caused by Moisture in Gas Chromatographic Analysis of Headspace SPME Samples of Short-Chain Amines

et al. 2018

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Volatile amines are usually problematic compounds in sampling, sample pretreatment and gas chromatographic analysis due to their chemical characteristics (polarity, basicity and reactivity). Headspace solid-phase microextraction (SPME) Arrow sampling of aqueous samples were proven to be complicated since moisture in the headspace was also sorbed into the SPME sorbent and resulted in distorted or split peaks for the volatile amines. This was the case especially with old used sorbents not so much with the new ones. Volume of the water sample, sampling conditions, quality of the SPME sorbent and desorption conditions greatly influenced the concentration of water in the headspace and in the sorbent phase. This, in turn, affected the length of the water film in the column which determined the degree of peak splitting and distance between the split amine peaks (water film trapped part of the amine molecules). Addition of the salt to the sample solution and additional drying of the SPME sorbent after the sampling were shown to effectively decrease the amount of water in the headspace and in the sorbent phase. This combined effect of salt addition and drying step resulted in much better peak shapes and intensities for the amines. In the best cases, the peak splitting for the volatile amines could in this way be completely avoided.

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Section: Electronic Supplementary Materialsmentioning

confidence: 99%

Problems Caused by Moisture in Gas Chromatographic Analysis of Headspace SPME Samples of Short-Chain Amines

et al. 2018

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“…Entre esses, destaca-se a metodologia da superfície de resposta, MSR. [12][13][14][15] A MSR permite desenvolver modelos matemáticos que podem ser otimizados, possibilitando uma melhoria na qualidade dos processos, porém a otimização de um processo fermentativo, quer se tenha em mente um aumento do rendimento ou produtividade, quer se deseje uma melhora na produção, implica, via de regra, na realização de estudos de caráter experimental para se observar a influência das variáveis no processo e de que modo pode-se trabalhar com as mesmas. 15 O objetivo do trabalho foi estudar a obtenção de etanol a partir da fermentação da farinha de Cyperus esculentus (CE), avaliando-se a e eficiência da hidrólise pela rota enzimática.…”

Section: Materiais E Métodosunclassified

Study of Alcohol Production Using as Feedstock the Cyperus esculentus (Tiririca)

et al. 2016

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Environmental problems caused by fossil fuels use and the need for a new path based on renewable energy sources leads biomass fuels development. Biofuels are considered strategic option for power generation, among them stands out ethanol. In order to minimize the competition with the food chain, the starch sources are alternatives biofuel obtainment, including the Cyperus esculentus (CE). This work aimed to study the ideal conditions for obtaining ethanol from CE flour fermentation, using the enzymatic route for the hydrolysis reaction. The fatorial design used was 3², in order to verify the influence of independents variables: fermentation time (h) and yeast concentration (g L -1 ) in enzymatic route, and degree alcoholic as the response (°GL). The tests in the raw material were realized, humidity content determination, starch content, reducing sugars (AR), chemically analyzed and scanning electronic microscopy (SEM) and UV-vis to determine the °GL response. The samples presented values humidity content 55.05%, starch content 52.38% and AR 12.23%. The SEM images showed elements protoxilema and protofloema. With the factorial design were achieved optimal conditions (15 g L -1 yeast concentration and 30 hours for fermentation time) for the production of ethanol with 24.27 ° GL.

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“…To increase the efficiency of finding the optimal factors, various statistical techniques have been proposed, particularly factorial designs. Among these techniques, response surface methodology (RSM) has been used by a significant number of researchers (AGUIRRE-GANZÁLES et al, 2011;SILVA et al, 2008).…”

Section: Introductionmentioning

confidence: 99%

Optimisation of the alcoholic fermentation of aqueous jerivá pulp extract

et al. 2014

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ABSTRACT. The objective of this research is to determinate the optimum conditions for the alcoholic fermentation process of aqueous jerivá pulp extract using the response surface methodology and simplex optimisation technique. The incomplete factorial design 3³ was applied with the yeast extract, NH 4 H 2 PO 4 and yeast as the independent variables and the alcohol production yield as the response. The regression analysis indicated that the model is predictive, and the simplex optimisation generated a formulation containing 0.35 g L NH 4 H 2 PO 4 for an optimum yield of 85.40% ethanol. To validate the predictive equation, the experiment was carried out in triplicate under optimum conditions, and an average yield of 87.15% was obtained. According to a t-test, no significant difference was observed (on the order of 5%) between the average value obtained and the value indicated by the simplex optimisation technique.Keywords: simplex optimisation, experimental design, yeast.Otimização da fermentação alcoólica de extrato aquoso da polpa de jerivá RESUMO. O objetivo deste trabalho foi determinar as melhores condições do processo de fermentação alcoólica do extrato aquoso da polpa de jerivá, utilizando a metodologia de superfície de resposta e otimização simplex. Foi empregado o delineamento fatorial incompleto 3 3 tendo o extrato de levedura, NH 4 H 2 PO 4 e levedura como variáveis independentes e o rendimento da produção de álcool como resposta. A análise da regressão mostrou que o modelo é preditivo e a otimização simplex indicou uma formulação contendo 0,35 g L -1de extrato de levedura, 6,33 g L -1de levedura e 0,30 g L -1de NH 4 H 2 PO 4 para um rendimento ótimo de produção de etanol de 85,40%. Para a validação da equação preditiva o experimento foi conduzido em triplicata, nas condições ótimas estabelecidas, obtendo-se um valor médio de 87,15% de rendimento. Aplicando-se o teste t, verificou-se que não houve diferença significativa, em nível de 5%, entre o valor médio obtido e aquele indicado na otimização simplex.Palavras-chaves: otimização simplex, delineamento experimental, levedura.

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Optimization of the HS-SPME technique by using response surface methodology for evaluating chlorine disinfection by-products by GC in drinking water

Cited by 13 publications

References 32 publications

Problems Caused by Moisture in Gas Chromatographic Analysis of Headspace SPME Samples of Short-Chain Amines

Problems Caused by Moisture in Gas Chromatographic Analysis of Headspace SPME Samples of Short-Chain Amines

Study of Alcohol Production Using as Feedstock the Cyperus esculentus (Tiririca)

Optimisation of the alcoholic fermentation of aqueous jerivá pulp extract

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