Robust flow–batch coulometric/biamperometric titration system: Determination of bromine index and bromine number of petrochemicals

Pasquini, Célio; Aquino, Emerson Vidal de; Rebouças, Márcio das Virgens; Gonzaga, Fabiano Barbieri

doi:10.1016/j.aca.2006.12.039

Cited by 25 publications

(16 citation statements)

References 17 publications

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“…Versatile and flexible flow-batch analyzers have been proposed to automate several analytical processes, 26,28,29 and extraction procedures.…”

Section: Introductionmentioning

confidence: 99%

“…Versatile and flexible flow-batch analyzers have been proposed to automate several analytical processes, 17,[22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41] such as hardness screening of water, 17 titrations, 40 analyses, in line coulometric generation of the standards or titrants 26,28,29 and extraction procedures. 41 In the present work, a FBA is employed to develop an automatic UV-Vis spectrophotometric screening analysis method for detection of adulteration in distilled spirits (whiskey, brandy, cachaça, rum and vodka).…”

Section: Introductionmentioning

confidence: 99%

“…Moreover, as most flow analyzers, FBA also presents good precision and accuracy, as well as high sample throughput and low consumption and manipulation of reagents and samples. Such features result in lower cost per analysis, reduced production of waste chemicals and fewer chances of human error.Versatile and flexible flow-batch analyzers have been proposed to automate several analytical processes, 26,28,29 and extraction procedures. …”

mentioning

confidence: 99%

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A flow-batch analyzer for UV-Vis spectrophotometric detection of adulteration in distilled spirits

Nascimento¹,

Araújo²,

Galvão³

2011

J. Braz. Chem. Soc.

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Um analisador flow-batch é proposto para detecção de adulterações em bebidas destiladas (uísque, conhaque, cachaça, rum e vodca) usando espectrofotometria UV-Vis. O analisador foi empregado para diluir as amostras não-adulteradas e para simular adulterações com adição de 5 e 10% (v/v) de água, etanol ou metanol. Modelos de classificação SIMCA (soft independent modelling of class analogies) foram construídos empregando espectros de amostras adulteradas e não-adulteradas na faixa de 235-355 nm. Aplicando-se os modelos SIMCA a um conjunto de teste, todas as amostras adulteradas e não-adulteradas foram corretamente discriminadas com um nível de confiança de 95% e uma frequência analítica superior a 120 amostras por hora.An automatic flow-batch analyzer is proposed for detection of adulteration in distilled spirits (whiskey, brandy, cachaça, rum and vodka) using UV-Vis spectrophotometry. The analyzer was employed to dilute the non-adulterated samples and to simulate adulteration with addition of 5 and 10% (v/v) of water, ethanol or methanol. SIMCA (soft independent modelling of class analogies) classification models were built using spectra of non-adulterated and adulterated samples in the region of 235-355 nm. By applying the SIMCA models to a test set, all adulterated and non-adulterated samples were correctly discriminated at a confidence level of 95% with an analytical throughput larger than 120 samples per hour.Keywords: flow-batch analyzer, SIMCA, UV-Vis spectrophotometry, adulteration of distilled spirits, screening analysis IntroductionThe adulteration of distilled spirits with water, ethanol or methanol is a problem with serious repercussions, which compromises the product quality, leads to loss of tax revenue and may constitute a public health threat. [1][2][3][4][5] In a study concerning the chemical composition of 608 beverage samples retailed in Brazil over the period [1993][1994][1995][1996][1997][1998][1999] 391 samples were found to be out of quality standards. 5 In two cases, the methanol levels were above the tolerance limit stated in Brazilian legislation. In that study, the analyses were carried out by chromatography in gaseous phase with a flame ionization detector.Chromatography is a powerful analytical method, which has been used in several works to detect adulteration in distilled spirits.6-8 However, such method presents some disadvantages, including high cost of the instrumentation, low analytical throughput, high consumption of reagents and samples and generation of harmful residues. 5,9 These limitations have motivated the development of spectrophotometric techniques for screening analysis [10][11][12][13][14][15][16][17][18][19] with the aim of reducing the number of samples that need to be analyzed by chromatographic methods. In this context, chemometrics plays a key role in the achievement of good screening results. [10][11][12] A previous work 10 proposed the use of near-infrared spectroscopy (NIR) and chemometrics to classify 69 samples of distilled spirits with respect to type (whi...

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“…Versatile and flexible flow-batch analyzers have been proposed to automate several analytical processes, 26,28,29 and extraction procedures.…”

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

mentioning

confidence: 99%

See 1 more Smart Citation

A flow-batch analyzer for UV-Vis spectrophotometric detection of adulteration in distilled spirits

Nascimento¹,

Araújo²,

Galvão³

2011

J. Braz. Chem. Soc.

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show abstract

“…The development of automatic systems has proved to be a good alternative way to circumvent these problems. Versatile and flexible flow-batch approaches (FBA) have been proposed to automate several analytical systems [28][29][30][31][32][33][34][35][36][37] and have been named and developed by our research group. As most of the flow analysers, FBA also present significant precision and accuracy, high sample throughput and low contamination, low consumption and manipulation of reagents and samples, low cost per analysis and low waste volumes.…”

Section: Introductionmentioning

confidence: 99%

Flow-batch analyser for preparation of calibration standard mixtures in simultaneous multicomponent spectrometric analysis

et al. 2009

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The application of multivariate calibration techniques to multicomponent analysis by UV-VIS molecular absorption spectrometry is a powerful tool for simultaneous determination of several chemical species. However, when this methodology is accomplished manually, it is slow and laborious, consumes high amounts of reagents and samples, is susceptible to contaminations and presents a high operational cost. To overcome these drawbacks, a flow-batch analyser is proposed in this work. This analyser was developed for automatic preparation of standard calibration and test (or validation) mixtures. It was applied to the simultaneous determination of Cu2+, Mn2+ and Zn2+ in polyvitaminic and polymineral pharmaceutical formulations, using 4-(2-piridilazo) resorcinol as reagent and a UV-VIS spectrophotometer with a photodiode array detector. The results obtained with the proposed system are in good agreement with those obtained by flame atomic absorption spectrometry, which was employed as reference method. With the proposed analyser, the preparation of calibration and test mixtures can be accomplished about four hours, while the manual procedure requires at least two days. Moreover, it consumes smaller amounts of reagents and samples than the manual procedure. After the preparation of calibration and test mixtures, 60 samples h-1 can be carried out with the proposed flow-batch analyser.

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“…Outras técnicas são exploradas para realizar a determinação deste elemento, como XRF combinada à espectroscopia Raman [211], XRF por reflexão total (TXRF) [212], WDXRF [213,214], EDS [215], análise por ativação com nêutrons (NAA) [216], ICP OES [215,217,218], e inclusive um sistema automatizado de titulação coulométrica e biamperométrica [219]. A maioria das técnicas acima citadas possuem base espectroscópica de radiação eletromagnética como meio de obtenção de dados, ainda que sejam radiações de alta energia, como as de XRF.…”

Section: Introductionunclassified

Desenvolvimento de procedimentos analíticos para a determinação de não-metais via moléculas diatômicas por espectrometria de absorção molecular de alta resolução com fonte contínua

Nakadi¹

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iii Dedico esta teseA meus pais, Ruth e Ivo, os quais me acompanham e incentivam o meu crescimento. Tudo o que me compõe é fruto de sua dedicação e carinho. Amo vocês.À minha irmã, Cintia, cuja companhia sempre me trouxe muita alegria, apesar do oposto não ser verdadeiro. Muito obrigado. Tabela 3. Determinação de bromo em amostra de teclas submetida à digestão ácida (DA) com posterior dissolução em NH4OH ou à extração Soxhlet (ES) com tolueno, com adição de bromo como NaBr. Intervalo de confiança de 95 % (n = 3)…………... 36 Tabela 4. Programa de temperatura utilizado para a determinação de enxofre em suspensão de carvão e cinzas por HR CS GFMAS……………………………………. 42 Tabela 5. Figuras de mérito da determinação de enxofre em carvão e cinzas via molécula CS por HR CS MAS………………………………………………………… 47 Tabela 6. Determinação de enxofre em suspensão de carvão e cinzas (CRMs) através da molécula de CS por HR CS GFMAS. A incerteza é expressa como intervalo de confiança de 95 % (n = 3)……………………………………………………………… 49 Tabela 7. Parâmetros utilizados para determinar enxofre via molécula de CS por HR CS MAS………………………………………………………………………………... 54 Tabela 8. Figuras de mérito do MEA e da ADD com avaliação do sinal da molécula CS determinada pela soma de 3 pixels (PC ± 1). Os LD e LQ apresentados fora do parêntesis foram calculados por, respectivamente, três e dez vezes o desvio padrão do branco (n = 10) dividido pela inclinação da curva de calibração. Os LD e LQ dos métodos estão dentro do parêntesis, considerando a diluição da amostra (aproximadamente 50 vezes para MEA) e massa de amostra (aproximadamente 3 mg para ADD)……………………………………………………………………………... 67 Tabela 9. Comparação entre a concentração de enxofre das amostras de referência determinadas pelo MEA e pelo método ASTM D 54353:2012 (certificado). As concentrações são expressas com média ± desvio padrão (n = 3)……………………... 68 Tabela 10. Determinação de enxofre como CS em 258,056 nm (PC ± 1) em amostras de diesel por MEA. Incertezas são expressas com intervalo de confiança de 95 % (n = 3). A recuperação de enxofre é expressa como porcentagem de recuperação de massa de enxofre adicionada na amostra (tioureia) com posterior determinação…………….. 69  e C 2  -por HR CS GFMAS, em diferentes transições vibracionais (v', v''). O deslocamento isotópico foi calculado pela Equação 3 e convertido em comprimento de onda para avaliar sua correlação com os dados experimentais. O valor de deslocamento isotópico entre parêntesis no comprimento de onda 600,24 nm corresponde ao observado experimentalmente………………...…. 110 Tabela 19. Determinação de bromo por SS-HR CS GFMAS por calibração externa e por ID. As incertezas experimentais são expressas como intervalo de confiança de 95 % (n = 5)……………………………………………………………………………….. TIMS -MS com ionização térmica (thermal ionization MS)TXRF -Fluorescência de raios-X por reflexão total (total reflexion X-ray fluorescence)

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Robust flow–batch coulometric/biamperometric titration system: Determination of bromine index and bromine number of petrochemicals

Cited by 25 publications

References 17 publications

A flow-batch analyzer for UV-Vis spectrophotometric detection of adulteration in distilled spirits

A flow-batch analyzer for UV-Vis spectrophotometric detection of adulteration in distilled spirits

Flow-batch analyser for preparation of calibration standard mixtures in simultaneous multicomponent spectrometric analysis

Desenvolvimento de procedimentos analíticos para a determinação de não-metais via moléculas diatômicas por espectrometria de absorção molecular de alta resolução com fonte contínua

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