Amostragem de suspensões: Emprego da técnica na análise direta de amostras

Magalhães, Carlos Emanuel de Carvalho; Arruda, Marco Aurélio Zezzi

doi:10.1590/s0100-40421998000400015

Cited by 25 publications

(16 citation statements)

References 84 publications

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“…Besides, equipment for direct solid analysis needs samplers suitable for such analysts. This analysis demonstrates that the suspension is more accurate than the direct sampling of solids [57,59].…”

Section: Suspensionmentioning

confidence: 81%

“…Although problems presented above regarding the use of sample introduction through suspension, there is still a great advantage as the introduction of direct analysis of solid samples in equipment. The direct determinations of solids require a calibration [57][58][59] patterns solids [57,58], the availability of these standards [57], which requires more cost, difficulty in obtaining a representative portion of the sample [60,61], sampling error in the portion to be analyzed, and the non homogeneous distribution of the analyte [59]. Besides, equipment for direct solid analysis needs samplers suitable for such analysts.…”

Section: Suspensionmentioning

confidence: 99%

See 1 more Smart Citation

Strategies to increase selectivity of analytical methods for As, Cr and Se speciation in biological samples: A review

Carvalho¹,

Coelho²,

Coelho³

et al. 2014

Sample Preparation

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Abstract:This review provides an overview and discusses different analytical strategies that minimize or eliminate the preparation of samples for speciation of organic and inorganic species of As, Cr and Se in samples of biological interest. These metals are important for the human body and the presence of various chemical forms of metals determines its essentiality and toxicity, thus speciation comes as an important tool for the study of biological samples. However, speciation requires a reduction in the steps of sample preparation, allowing a sample investigation in its most native form in order to reduce the changes in chemical species. The strategies proposed for speciation of these metals include: solid phase extraction, point cloud extraction, suspension and direct analysis. Selected methods proposed for the speciation of organic and inorganic species of As, Cr and Se were reviewed including their main figures of merit, advantages and disadvantages.

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Section: Suspensionmentioning

confidence: 81%

Section: Suspensionmentioning

confidence: 99%

Strategies to increase selectivity of analytical methods for As, Cr and Se speciation in biological samples: A review

Carvalho¹,

Coelho²,

Coelho³

et al. 2014

Sample Preparation

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“…No losses of volatile elements, safety of operation, and the small amount of sample are attractive characteristics of this method. 9,18,44,[54][55][56][57][58][59][60] Direct solid sampling electrothermal atomic absorption spectrometry (SS-ETAAS) is applicable to trace and ultratrace element determination in technological, biological and environmental samples. 55,61 Reduced sample requirements, the possibility of performing the sample decomposition inside the graphite furnace, operational simplicity and high detectability are the main attributes of SS-ETAAS.…”

Section: Solid Samples and Slurry Analysismentioning

confidence: 99%

Sample preparation for atomic spectroscopy: evolution and future trends

Oliveira¹

2003

J. Braz. Chem. Soc.

137

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A preparação da amostra é a etapa crítica dentro de um protocolo analítico e envolve desde a simples diluição até a solubilização parcial ou total. Métodos de decomposição por via seca ou úmida, envolvendo o aquecimento das amostras em sistemas abertos ou fechados, utilizando várias formas de energia como térmica, ultra-som ou radiante (infravermelho, ultravioleta e microondas) são empregados. O presente e o futuro da preparação de amostras consideram também solubilização em linha de amostras, lixiviação dos analitos de interesse, especiação, análise de suspensão, análise in situ, in vivo etc. Ênfase foi dada para o preparo de amostras para espectroscopia atômica. Atualmente, os objetivos a serem alcançados envolvem a obtenção do melhor resultado, no menor tempo, com mínima contaminação, pouco gasto de reagente e pequena geração de resíduos e efluentes, bem como a integridade das amostras e traceabilidade dos resultados, tendo em mente a qualidade e confiança nos resultados de medições, como requerido pela comunidade e usuários.Sample preparation is the critical step of any analytical protocol, and involves steps from simple dilution to partial or total dissolution. The methods include dry or wet decomposition of the samples in open or closed systems, using thermal, ultrasonic or radiant (infrared, ultraviolet and microwaves) energy. This review emphasizes sample preparation for atomic spectroscopy. The present and future tendencies for sample preparation also involve on-line dissolution, extraction of the analytes, speciation, solid sample and slurry analysis, in situ and in vivo procedures, etc. Nowadays the goals are the best result, in the shortest time, with minimum contamination, using the smallest quantities of reagents and samples, and having low residue and waste generation, as well as maintaining the integrity of the sample and the traceability of the results, to have quality and confidence in the measurements as the primordial attributes required by the community and by the users.

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“…A GF AAS apresenta características que a elegem como uma das técnicas mais adequadas para análise direta de sólidos, seja na forma de suspensão (SiS GF AAS) ou de sólido direto (SS GF AAS) [4][5][6][7][8][9][10][11] . Dentre as suas principais características, destacam-se: o programa de aquecimento que permite o pré-tratamento térmico da amostra, sobretudo durante a etapa de pirólise, o que facilita a remoção de parte dos concomitantes que podem provocar interferências durante a atomização; as pequenas quantidades de amostras que podem ser analisadas; apresenta boa seletividade e sensibilidade; os problemas relacionados ao sistema de transporte são praticamente inexistentes, uma vez que o transporte das suspensões é feito por amostragem discreta (não depende de nebulizadores), e os sólidos são pesados diretamente nas plataformas de grafite que são, posteriormente, introduzidas no atomizador eletrotérmico e, a adequada otimização do programa de aquecimento, aliada ao uso de modificadores químicos, possibilita, na maioria das vezes, a calibração do equipamento com soluções aquosas.…”

Section: Introductionunclassified