Automated sample deoxygenation for improved luminescence measurements

Rollie, Mae E.; Patonay, Gábor; Warner, Isiah M.

doi:10.1021/ac00128a037

Cited by 11 publications

(7 citation statements)

References 25 publications

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“…Ideally, techniques to reduce photobleaching, such as the addition of UV absorbers, solution deoxygenation, and the use of nanosecond-pulsed lasers or fast shuttering to decrease sample exposure (54)(55)(56)(57)(58),…”

Section: Stabilitymentioning

confidence: 99%

Luminescence Standards for Macro- and Microspectrofluorometry

Velapoldi

Epstein

1989

ACS Symposium Series

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Requirements for standards used in macro-and micro spectrofluorometry differ, depending on whether they are used for instrument calibration, standardization, or assessment of method accuracy. Specific examples are given of standards for quantum yield, number of quanta, and decay time, and for calibration of instrument parameters, including wavelength, spectral responsivity (determining correction factors for luminescence spectra), stability, and linearity. Differences in requirements for macro-and micro-standards are consid ered, and specific materials used for each are compared. Pure compounds and matrix-matched standards are listed for standardization and assessment of method accuracy, and existing Standard Reference Materials are discussed.The inherent sensitivity and selectivity of spectrofluorometry, coupled with the advances in electro-optical components and computers, has led to the wide use of spectrofluorometry during the last three decades in diverse areas of analysis, including analytical chemistry, cellular biology, geochemistry, and mail sorting systems The information obtained from these measurements has had a profound impact on all of these areas, for example, in assessing molecular interactions used for qualitative and quantitative analyses, chromatographic separations, cellular make-up and interactions, molecular volume, rotation and diffusion coefficients for large molecules, determination of porosities of geologic samples on a micro-and macro-scale, photochemical and kinetic processes, and energy transformation/conversion.In general, luminescence measurements are relative rather than absolute, since the instrument characteristics and sample properties that determine the fluorescence intensities are often not well defined.Absolute luminescence measurements are difficult to perform and require time and instrumentation not available in most laboratories.Thus, luminescence measurements rely heavily on standards to determine instrument responses and parameters, the chemical composition of samples, and the characteristics of chemical systems. To This chapter not subject to U.S.

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Section: Stabilitymentioning

confidence: 99%

Luminescence Standards for Macro- and Microspectrofluorometry

Velapoldi

Epstein

1989

ACS Symposium Series

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“…As características de todas as soluções fosforescentes e a grande maioria das fluorescentes são adversamente afetadas pela presença do oxigênio à temperatura ambiente (12). Algumas moléculas excitadas têm seu sinal luminescente dinamicamente suprimido após colisões com oxigênio molecular (13,14,15).…”

Section: 2unclassified

“…Muitos destes métodos apresentam eficiência de remoção de até 95% ou mais, dependendo do tempo aplicado do procedimento. Cada um desses métodos tem limitações quanto à facilidade de uso, quantidade de amostra, consumo de tempo e eficiência de desoxigenação (12,46,47,48).…”

Section: 2unclassified

“…Para superar as dificuldades associadas à remoção do oxigênio dissolvido na análise em fluxo, diferentes sistemas contínuos têm sido propostos, os quais incluem métodos químicos, eletroanalíticos, fotoquímicos e físicos (12,15,47,48).…”

Section: 2unclassified

“…Ocorre um processo de difusão de gás através das paredes desses tubos permeáveis pela geração de um gradiente de concentração (12,15,47,48).…”

Section: Avaliação Do Sistema De Remoção De Gasesunclassified

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Estudo de alguns indicadores fluorescentes para oxigênio em solução aquosa

Stein¹

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AgradecimentosÀ profa. Ora. Nina Coichev e todo grupo de pesquisa pela amizade e paciência. Ao grupo da Profa. Ora. Silvia Serrano pelo companheirismo.Aos professores Or. Gianluca C. Azzellini e Or. Jairo J. Pedrotti pela colaboração e muitas dúvidas sanadas.A todos os funcionários, professores e alunos do Instituto de Química da USP pelo convívio agradável. A todos aqueles que de alguma forma colaboraram para este trabalho e aqueles que simplesmente não atrapalharam.Ao CNPq e FAPESP pelo suporte financeiro.Aos amigos pelo carinho, apoio e incentivo constante.

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Fluorescence in Organized Assemblies

Memon¹,

Balouch²,

Hinze³

2008

Encyclopedia of Analytical Chemistry

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This article provides an overview of the general properties of organized assembly (ordered media) systems, such as aqueous surfactant and bile salt micelles, lipid (liposomes) and surfactant vesicles, and cyclodextrins (CDs), and summarizes their utilization to enhance the performance of analytical fluorescence measurements. In many instances, organic molecules and metal complex species when included within a CD cavity or solubilized and bound to surfactant aggregates exhibit enhanced fluorescence, improving detectability of such analytes. The altered microenvironment within the organized medium can impede the interfering action of other species (inorganic or organic) present in the sample matrix, which often improves the selectivity of the analytical method. These benefits of improved sensitivity and selectivity arise from the compartmentalization, isolation, and shielding of the excited singlet state of the guest analyte from quenching and nonradiative decay processes, as well as preventing side reactions that otherwise can occur in bulk solution (or sample matrix). Organic solvents or time‐consuming extraction steps can also be avoided, owing to the increased solubility of nonpolar organic or inorganic reagents and/or analyte molecules in water in the presence of the organized medium, allowing the use of an aqueous medium to perform the procedure. The possibility of conducting reactions and forming fluorescent organic or metal chelates in micellar (or other organized) media that are not observed in a bulk homogeneous solvent system serves to expand the scope of possible chemistries for design/development of new, unique, and improved fluorescent assays. Examples of fluorescent methods for determination of both organic and inorganic analytes are provided, which serve to illustrate the advantages and benefits accrued from the use of the micelles, vesicles, liposomes, or CDs in such procedures, along with experimental considerations and cautions in utilizing organized media.

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Automated sample deoxygenation for improved luminescence measurements

Cited by 11 publications

References 25 publications

Luminescence Standards for Macro- and Microspectrofluorometry

Luminescence Standards for Macro- and Microspectrofluorometry

Estudo de alguns indicadores fluorescentes para oxigênio em solução aquosa

Fluorescence in Organized Assemblies

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