Padronização interna em espectrometria de absorção atômica

Fernandes, Kelly G.; Moraes, Mercedes de; Neto, José Anchieta Gomes; Nóbrega, Joaquim A.; Oliveira, Pedro Vitoriano de

doi:10.1590/s0100-40422003000200018

Cited by 14 publications

(9 citation statements)

References 14 publications

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“…In particular, due to the common fluctuations observed in LIBS measurements associated to both, instrumentation and sample heterogeneity, various strategies are experimented for the calibration of LIBS methods, which include various different spectral preprocessing and multivariate (linear and non-linear) calibration models [17][18][19][20]. Among these, internal standardization, which consists in normalizing the analyte signal by the signal of an internal standard (IS), is a well known methodology used to minimize fluctuations in spectroscopic techniques including LIBS [21][22][23][24]. To perform internal standardization, the IS concentration must be known and nearly constant [25,26].…”

Section: Introductionmentioning

confidence: 99%

Calcium determination in biochar-based fertilizers by laser-induced breakdown spectroscopy using sodium as internal standard

Morais

Barros

Júnior

et al. 2017

Microchemical Journal

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Biochar has gained agricultural importance as a soil amendment because of its important agricultural properties such as water retention, plant nutrient supplier, promoter of microorganism growth, sequestration action of atmospheric CO 2 , etc. Further, it is a low cost material being produced by recycling. Due to its active sites, biochar can adsorb nutrients so acting as a soil fertilizer. Thus the rapid assessment of nutrients in these materials is essential to ensure quality control for agricultural purposes. This work aimed to develop a simple analytical method based on Laser-Induced Breakdown Spectroscopy (LIBS) to determine Ca in biochar-based fertilizers. In particular, biochar samples enriched with Ca were prepared from peanut shells, residues of eucalyptus and banana fibers. The calibration standards were prepared by matrix matching using a biochar from eucalyptus residues. Different spectral preprocessing were evaluated to enhance the precision and accuracy of the method. However, the matrix effects demanded the use of internal standardization as the appropriate methodology to obtain the best accuracy. A linear correlation coefficient of 0.989 and a linear work range of 1.51-11.23% Ca were obtained using the proposed method, which yielded limits of detection and quantification of 0.45% e 1.51%, respectively. Calcium contents determined by LIBS in biochar-based fertilizers were in good agreement (paired t-test at 95% confidence level) with those determined by using High-Resolution Continuous Source Atomic Absorption Spectrometry (HR-CS FAAS) as the reference technique. Thus, the importance of internal standardization was demonstrated to be successful for the quantitative analysis of Ca in complex matrices like biochar-based fertilizers.

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Section: Introductionmentioning

confidence: 99%

Calcium determination in biochar-based fertilizers by laser-induced breakdown spectroscopy using sodium as internal standard

Morais

Barros

Júnior

et al. 2017

Microchemical Journal

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“…Consequently, separation and preconcentration procedures are often needed before GFAAS determination. Various techniques have been applied for the separation and preconcentration of trace Cd and Pb, such as liquid-liquid extraction, 9,10 coprecipitation, 11 solid-phase ex-traction, [12][13][14][15][16] cloud point extraction [17][18][19] and liquid-phase microextraction, 20,21 but the disadvantages such as timeconsuming, unsatisfactory enrichment factors, large organic solvents and secondary wastes, limit their applications. In order to overcome the problems, a novel liquid-liquid extraction technique termed as dispersive liquid-liquid microextraction (DLLME), which is based on a ternary component solvent system like homogeneous liquid-liquid extraction, was proposed recently.…”

Section: Introductionmentioning

confidence: 99%

Determination of Cadmium and Lead in Human Teeth Samples Using Dispersive Liquid‐liquid Microextraction and Graphite Furnace Atomic Absorption Spectrometry

Cheng

Xia

Liang

2011

J Chinese Chemical Soc

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A new method for the determination of cadmium and lead in human teeth was developed based on dispersive liquid-liquid microextraction preconcentration and graphite furnace atomic absorption spectrometry determination. In the proposed approach, O,O-diethyldithiophosphate (DDTP) was used as a chelating agent, and carbon tetrachloride and methanol were selected as extraction and dispersive solvents. Some factors influencing the extraction efficiency of cadmium and lead and their subsequent determination, including extraction and dispersive solvent type and volume, pH of sample solution, concentration of the chelating agent and extraction time, were studied and optimized. Under the optimum conditions, the enrichment factor of 116 and 68 for cadmium and lead were achieved. The detection limit for cadmium and lead was 5.6 and 45 ng L -1 , and the relative standard deviation (R.S.D) was 4.5% and 3.8% (n = 7, c = 1.0 ng mL -1 ), respectively. Verification of the accuracy of the method was carried out by analysis of a standard reference material (NIST 1486, bone meal). The method was successfully applied to the determination of trace amount of cadmium and lead in human teeth samples with satisfactory results.

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“…Tais avanços incluem a aplicação de novos procedimentos para introdução de amostras em suspensão, sólidas e na fase gasosa; 76 o uso de sistemas alternativos de atomização, como o filamento de tungstênio e o forno-filtro com aquecimento transversal; 77 fontes contínuas de radiação; sistemas de alta resolução, abrangendo os arranjos de detectores de carga acoplada 78 e detectores de estado sólido; 79 utilização de padronização interna para minimizar erros e possíveis efeitos interferentes. [80][81][82][83][84] Mesmo havendo desafios a serem superados na determinação multi-elementar, a AAS alcançou avanços que mais uma vez a colocam nos rumos para suprir os anseios da química moderna. …”

Section: Determinação Multi-elementar Seqüencialunclassified

Espectrometria de absorção atômica: o caminho para determinações multi-elementares

Amorim¹,

Lôbo²,

Santos³

et al. 2008

Quím. Nova

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Recebido em 23/3/07; aceito em 19/12/07; publicado na web em 11/9/08 ATOMIC ABSORPTION SPECTROMETRY: THE WAY FOR MULTIELEMENT DETERMINATIONS. This paper present an overview of way covered for the spectrometry of atomic absorption (AAS), tracing a line of the historical events in its development and its establishment as a multielement technique. Additionally, the efforts carried by through several researchers in the search for the instrumental evolution, the advances, advantages, limitations, and trends of this approach are related. Several works focusing its analytical applications are cited employing simultaneous multielement determination by flame (FAAS) and/or graphite furnace (GF AAS), and fast sequential multielement determination using FAAS are reported in the present review.Keywords: multielement AAS; simultaneous determination; fast sequential FAAS. introduçãoConsiderada como uma técnica analítica bem sucedida, a espectrometria de absorção atômica (AAS -Atomic Absorption Spectrometry) é uma das mais utilizadas na determinação de elementos em baixas concentrações, que estão presentes numa variedade de amostras, sejam estas líquidas, sólidas, em suspensão, e até mesmo gasosas, podendo estar associada a sistemas de análise em fluxo e permitir estudos de especiação. 1,2Todas as aplicações analíticas modernas da AAS tiveram origem a partir de trabalhos publicados no final da década de 50, 3,4 que propuseram pela primeira vez o uso da AAS para análises químicas. Marcando, em 2005, o aniversário de 50 anos de existência desta publicação, deve-se reconhecer que o uso da AAS muito contribuiu para o progresso científico neste meio século.6-10 Entretanto, deve-se também reconhecer que esta técnica apresenta limitações, particularmente quando comparada com a espectrometria de emissão óptica com plasma indutivamente acoplado (ICP OES -Inductively Coupled Plasma Optical Emission Spectrometry) e a espectrometria de massa com plasma indutivamente acoplado (ICP-MS -Inductively Coupled Plasma Mass Spectrometry), que são conceitualmente estabelecidas como técnicas multi-elementares, característica que não é atribuída à AAS. 11,12Neste sentido, apresenta-se a seguir uma revisão envolvendo o uso da AAS para determinações multi-elementares, registrando os esforços realizados por diversos pesquisadores na busca pelo desenvolvimento instrumental, apontando as tendências evolutivas desta técnica, focalizando suas aplicações analíticas. absorção atômica: o inÍcioA espectrometria atômica teve papel fundamental no desenvolvimento da química. Esta página da história teve início com os experimentos de Joannes M. Marci, em 1648, através de suas observações a respeito da origem do arco-íris com bases no espalhamento da luz solar nas gotículas d'água.1 Mais tarde, em 1672, Isaac Newton descrevia a decomposição e recomposição da luz do sol por um prisma. Daí por diante, vários experimentos foram realizados com o espectro oriundo da decomposição da luz solar, a exemplo da descoberta da região do infravermelho pelo inglês William Herschel,...

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Padronização interna em espectrometria de absorção atômica

Cited by 14 publications

References 14 publications

Calcium determination in biochar-based fertilizers by laser-induced breakdown spectroscopy using sodium as internal standard

Calcium determination in biochar-based fertilizers by laser-induced breakdown spectroscopy using sodium as internal standard

Determination of Cadmium and Lead in Human Teeth Samples Using Dispersive Liquid‐liquid Microextraction and Graphite Furnace Atomic Absorption Spectrometry

Espectrometria de absorção atômica: o caminho para determinações multi-elementares

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