An improved procedure for flow-based turbidimetric sulphate determination based on a liquid core waveguide and pulsed flows

Melchert, Wanessa R.; Rocha, Fábio R.P.

doi:10.1016/j.aca.2008.04.014

Cited by 30 publications

(10 citation statements)

References 33 publications

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“…Santos et al 107 presented a systematic comparison among spectrophotometric flow injection procedures for sulfide determination based on phenothiazine dye production from diverse aromatic p-substituted amines. Melchert and Rocha 108 presented a flow-based procedure for turbidimetric sulfate determination in waters. The mixing conditions were improved with the help of solenoid micro-pumps and sensitivity was increased by coupling a long-pathlength flow cell based on a liquid core waveguide.…”

Section: Environmentalmentioning

confidence: 99%

“…Vortices produced by the actuation of the solenoid micropumps contribute to enhance radial mass transport and to avoid solid deposition as previously mentioned. 108 Hyphenation of a flow injection system to capillary electrophoresis was exploited for on-line preconcentration on an anionic resin column. 297 Sensitivity improvement was estimated as 660%, without critically affecting resolution (peak dispersion increased in 8%).…”

Section: Instrumentation and Automationmentioning

confidence: 99%

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Analytical chemistry in Brazil: healthy and growing

Rocha

Pereira-Filho²,

Nóbrega³

2009

J. Braz. Chem. Soc.

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A química brasileira está crescendo rapidamente, sendo um dos principais alicerces para o contínuo desenvolvimento do país. Inspirados no 15º Encontro Nacional de Química Analítica, ENQA, com um número recorde de participantes e comunicações, decidiu-se revisar os recentes desenvolvimentos em química analítica no Brasil. Foram escolhidas as mesmas áreas de aplicação adotadas para a organização temática do ENQA e selecionados artigos publicados por autores brasileiros em 7 periódicos de ampla penetração na área. Os dois periódicos científicos editados pela Sociedade Brasileira de Química também foram pesquisados. Esta revisão não é exaustiva, porém os trabalhos selecionados após 2008 mostram uma significativa visão geral da área. Pode-se concluir que a química analítica brasileira está saudável, em crescimento e certamente atenderá as demandas do país como uma potência emergida.Chemical sciences in Brazil are growing fast and being one of the main supports for the continuous development of the country. Inspired on the 15 th Brazilian Meeting on Analytical Chemistry, ENQA, with a record number of participants and communications, we have decided to review recent developments in analytical chemistry in Brazil. We have chosen the same application areas used for the thematic organization of the ENQA and have searched papers published by Brazilian authors in 7 major and general journals in analytical chemistry. The two scientific journals published by the Brazilian Chemical Society were also searched. This review is not comprehensive, but the selected papers published after 2008 shown an impressive overview of the area. We may conclude that analytical chemistry is healthy and growing in Brazilian scenario and certainly will attend the demands of Brazil as an emerged power.

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Section: Environmentalmentioning

confidence: 99%

Section: Instrumentation and Automationmentioning

confidence: 99%

Analytical chemistry in Brazil: healthy and growing

Rocha

Pereira-Filho²,

Nóbrega³

2009

J. Braz. Chem. Soc.

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“…The addition of lead and the use of a reversed precipitation flowinjection device has been applied to the sulfate determination by means of FAAS in the 2 -20 mg L -1 concentration range with a 60 h -1 sample throughput [14]. Turbidimetric methods have also been automated [15,16]. In a sequential injection analysis approach the achieved detection limit was 2.0 mg L -1 [17].…”

mentioning

confidence: 99%

Ion balance in waters through inductively coupled plasma optical emission spectrometry

Sanchez

Pérez

Prats

et al. 2013

International Journal of Environmental Analytical Chemistry

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Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) has been employed to carry out the determination of both major anions and cations in water samples. The anions quantification has been performed by means of a new automatic accessory. In this device chloride has been determined by continuously adding a silver nitrate solution. As a result solid silver chloride particles are formed and retained on a Nylon filter inserted in the line. The emission intensity is read at a silver characteristic wavelength. By plotting the drop in silver signal versus the chloride concentration, a straight line is obtained. As regards bicarbonate, this anion has been on-line transformed into carbon dioxide with the help of a 2.0 mol L-1 nitric acid stream. Carbon signal is linearly related with bicarbonate concentration. Finally, information about sulfate concentration has been achieved by means of the measurement of sulfur emission intensity. All the steps have been simultaneously and automatically performed. With this setup detection limits have been 1.0, 0.4 and 0.09 mg L-1 for chloride, bicarbonate and sulfate, respectively. Furthermore, it affords good precision with RSD below 6 %. Cations (Ca, Mg, Na and K) concentration, in turn, has been obtained by simultaneously reading the emission intensity at characteristic wavelengths. The obtained limits of detection have been 8 x 10-3 , 2 x 10-3 , 8 x 10-4 and 10-2 mg L-1 for sodium, potassium, magnesium and calcium, respectively. As regards sample throughput about 30 samples h-1 can be analyzed. Validation results have revealed that the obtained concentrations for these anions are not significantly different as compared to the data provided by conventional methods. Finally, by considering the data for anions and cations precise ion balances have been obtained for well and mineral water samples.

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“…The accuracy was assessed by comparison of results with those obtained by ionchromatography; no significant difference was observed at the 95% confidence level. Em meio aquoso, a formação dos cristais de sulfato de bário (nucleação) é lenta e depende de alguns fatores, como excesso de bário e meio reacional ácido [111][112][113][114]. Muitas vezes essa formação é acelerada e estabilizada por meio da adição de agentes tensoativos [111,113].…”

Section: Introductionunclassified

“…Em meio aquoso, a formação dos cristais de sulfato de bário (nucleação) é lenta e depende de alguns fatores, como excesso de bário e meio reacional ácido [111][112][113][114]. Muitas vezes essa formação é acelerada e estabilizada por meio da adição de agentes tensoativos [111,113]. Ao se aplicar o teste-t de Student para amostras pareadas, os resultados apresentaram concordância ao nível de confiança de 95%.…”

Section: Introductionunclassified

Estratégias em fluxo para a determinação de acidez, sulfato e cloreto em etanol hidratado combustível

Lima¹

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An improved procedure for flow-based turbidimetric sulphate determination based on a liquid core waveguide and pulsed flows

Cited by 30 publications

References 33 publications

Analytical chemistry in Brazil: healthy and growing

Analytical chemistry in Brazil: healthy and growing

Ion balance in waters through inductively coupled plasma optical emission spectrometry

Estratégias em fluxo para a determinação de acidez, sulfato e cloreto em etanol hidratado combustível

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