Colorimetric Determination of Sulfate with Barium Chloranilate

Bertolacini, Ralph; Barney, J. E.

doi:10.1021/ac60122a031

Cited by 317 publications

(63 citation statements)

References 15 publications

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“…The solubility of barium chloranilate is also repressed by the presence of organic solvents; it is recommended that the reaction with sulfate be carried out in 50% ethanol. 2 After trying carrier solutions of various compositions, a solution containing 0.5% NH4C1 and 50% ethanol (pH 5.25) was chosen to be the carrier solution.…”

Section: Recommended Proceduresmentioning

confidence: 99%

Determination of the Sulfate Ion Concentration in Rain Water by Flow Injection Analysis Incorporated with a Barium Chloranilate Reaction Column

et al. 1990

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The concentration of sulfate ions in rain water was determined by a flow-injection method using a reaction column packed with barium chloranilate powder. Aqueous ammonium chloride (0.5%) containing 50% ethanol was used as a carrier at a flow rate of 1.9 ml/ min. The chloranilate ion concentration, which corresponds to the sulfate ion concentration, in the carrier from the reaction column was monitored by a photometric detector at 530 nm. Interferences by multivalent cations were eliminated with the use of a cation-exchange column inserted in the upper stream of the reaction column. The concentrations of sulfate ions in rain water (4 -100 ppm) were quickly determined (one sample per minute) with high reproducibility. The results agreed well with those obtained by the standard manual method.

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Section: Recommended Proceduresmentioning

confidence: 99%

Determination of the Sulfate Ion Concentration in Rain Water by Flow Injection Analysis Incorporated with a Barium Chloranilate Reaction Column

et al. 1990

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“…The concentrations of As, Cd, Cu, Ni, Pb, Zn in the filtrated samples were analyzed by an inductively coupled plasma-optical emission spectrophotometer (ICP-OES, 730-ES, Varian Inc., USA). Sulfate concentrations in aqueous phases were determined by a colorimetric method (DR2800, HACH, USA) (Bertolacini and Barney, 1957).…”

Section: Analytical Techniquesmentioning

confidence: 99%

Effects of Extracellular Electron Shuttles on Microbial Iron Reduction and Heavy Metals Release from Contaminated Soils

Hwang¹,

Shim²,

Oh³

et al. 2014

Journal of Soil and Groundwater Environment

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To test the potential effects of extracellular electron shuttles (EES) on the rate and extent of heavy metal release from contaminated soils during microbial iron reduction, we created anaerobic batch systems with anthraquinone-2,6-disulfonate (AQDS) as a surrogate of EES, and with contaminated soils as mixed iron (hydr)oxides and microbial sources.Two types of soils were tested: Zn-contaminated soil A and As/Pb-contaminated soil B. In soil A, the rate of iron reduction was fastest in the presence of AQDS and > 3500 mg/L of total Fe(II) was produced within 2 d. This suggests that indigenous microorganisms can utilize AQDS as EES to stimulate iron reduction. In the incubations with soil B, the rate and extent of iron reduction did not increase in the presence of AQDS likely because of the low pH (< 5.5). In addition, less than 2000 mg/L of total Fe(II) was produced in soil B within 52 d suggesting that iron reduction by subsurface microorganisms in soil B was not as effective as that in soil A. Relatively high amount of As (~500 mg/L) was released to the aqueous phase during microbial iron reduction in soil B. The release of As might be due to the reduction of As-associated iron (hydr)oxides and/or direct enzymatic reduction of As(V) to As(III) by As-reducing microorganisms. However, given that Pb in liquid phase was < 0.3 mg/L for the entire experiment, the microbial reduction As(V) to As(III) by As-reducing microorganisms has most likely occurred in this system. This study suggests that heavy metal release from contaminated soils can be strongly controlled by subsurface microorganisms, soil pH, presence of EES, and/or nature of heavy metals.

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“…Métodos espectrofotométricos são de aplicação restrita principalmente porque o sulfato forma poucos compostos coloridos que absorvem radiação no visível e ultra-violeta, o que resulta na dificuldade de emprego dos mesmos 10 No presente trabalho foi desenvolvido um procedimento automatizado baseado no conceito FIA, utilizando-se um reagente sólido e o analito líquido. Os estudos foram feitos empregando reagente na forma de suspensão, visando demonstrar mais uma possibilidade do uso desta técnica de análise.…”

Section: Introductionunclassified

“…Uma vez que o cloranilato de bário é pouco solúvel em água, a reação é proposta em meio etanólico permitindo assim um ganho em sensibilidade do método 10 . Com este propósito também foi sugerida a reação dos íons cloranílico com íons férrico para formar um complexo de cor púrpura, o que provocou um aumento nos valores de absorbância das soluções 11 .…”

Section: Introductionunclassified

Emprego de reagente em suspensão em sistema de injeção em fluxo: determinação espectrofotométrica de sulfato em águas naturais

Crnkovic¹,

Jacintho²

2002

Quím. Nova

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Reccebido em 2/3/01; aceito em 26/7/01 USE OF REAGENT IN SUSPENSION IN FLOW INJECTION ANALYSIS. SPECTROPHOTOMETRIC DETERMINATION OF SULPHATE IN NATURAL WATER. This paper presents an automatic procedure employing a reagent in the form of a slurry in a flow-injection system. The feasibility of the proposal is demonstrated by sulphate determination in water using the Barium Chloranilate method, which is based on the precipitation of barium sulphate. The release of a stoichiometric amount of highly colored chloranilic ions is monitored at 528 nm. The reaction is carried out in alcoholic medium in order to reduce the solubility of the reagent. A considerable improvement in the sensitivity is attained by adding ferric ions to the released chloranilic ions. An on-line filtration step to separate the excess reagent from the released chloranilic ions was necessary. In addition, a column containing a cation exchange resin was included in the manifold to remove potentially interfering ions. The proposed procedure is suitable for 30 determinations per hour and the relative standard deviation is less than 2%. The analytical curve is linear between 0.0 and 40 mg L -1 and the determination limit is about 2.0 mg L -1 SO 4 2-. Accuracy was confirmed by running several samples already analysed by a standard turbidimetric procedure.Keywords: slurry reagent; barium chloranilate; sulphate. INTRODUÇÃOInterações sólido-líquido são utilizadas em sistema de análise em fluxo (FIA) com o objetivo de quantificação. O emprego do reagente empacotado em colunas pode aumentar a eficiência da reação, pois o problema da dispersão da amostra é minimizado, porém uma restrição quando se utiliza esta técnica diz respeito à falta de reprodutibilidade, devido à degradação do reagente ou saturação dos sítios ativos que aumentam com o tempo, havendo então a necessidade de freqüente renovação da coluna e calibração 1 .Alguns autores apresentaram esta possibilidade descrevendo sistemas onde a parte sólida pode ser acomodada em coluna 2-4 , utilizando-se ou não a imobilização em partículas esféricas de celulose 5,6 . O uso de câmara de agitação também foi proposto para esta finalidade 7 , onde um contato vigoroso entre reagente pouco solúvel e amostra líquida é necessário, pois esta interação química dá origem a uma terceira espécie mensurável espectrofotometricamente.O emprego de suspensão em FIA também se constitui uma alternativa para as reações que requerem o uso de reagentes sólidos e pouco solúveis. Proposta neste sentido foi sugerida utilizando sistema automatizado, segmentado com bolhas de ar 8 .Reações que envolvem a existência de mais de uma fase apresentam problemas relacionados à complexidade deste fenômeno. Qualquer variação nas condições e manuseio de soluções que envolvem formação de colóides pode resultar em perda de precisão de uma determinação para outra. Com o uso de sistema de análise em fluxo, podem-se repetir as condições a cada ciclo, o que torna viável a reprodutibilidade do procedimento.Vários métodos analíticos têm sido propostos ...

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Colorimetric Determination of Sulfate with Barium Chloranilate

Cited by 317 publications

References 15 publications

Determination of the Sulfate Ion Concentration in Rain Water by Flow Injection Analysis Incorporated with a Barium Chloranilate Reaction Column

Determination of the Sulfate Ion Concentration in Rain Water by Flow Injection Analysis Incorporated with a Barium Chloranilate Reaction Column

Effects of Extracellular Electron Shuttles on Microbial Iron Reduction and Heavy Metals Release from Contaminated Soils

Emprego de reagente em suspensão em sistema de injeção em fluxo: determinação espectrofotométrica de sulfato em águas naturais

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