Determination of Cd and Pb in food slurries by GFAAS using cryogenic grinding for sample preparation

Santos, Daniele Cristina Muniz Batista dos; Barbosa, Fernando; Tomazelli, A. C.; Krug, Francisco José; Nóbrega, Joaquim A.; Arruda, Marco Aurélio Zezzi

doi:10.1007/s00216-002-1296-9

Cited by 64 publications

(34 citation statements)

References 38 publications

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“…The potentialities of using cryogenic grinding are described elsewhere. [36][37][38] The following certified reference materials were used for evaluation of fs-LIBS for elemental determina- …”

Section: Methodsmentioning

confidence: 99%

Evaluation of Femtosecond Laser-Induced Breakdown Spectroscopy for Analysis of Animal Tissues

et al. 2008

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The aim of this work was to evaluate the performance of femtosecond laser-induced breakdown spectroscopy (fs-LIBS) for the determination of elements in animal tissues. Sample pellets were prepared from certified reference materials, such as liver, kidney, muscle, hepatopancreas, and oyster, after cryogenic grinding assisted homogenization. Individual samples were placed in a two-axis computer-controlled translation stage that moved in the plane orthogonal to a beam originating from a Ti:Sapphire chirped-pulse amplification (CPA) laser system operating at 800 nm and producing a train of 840 lJ and 40 fs pulses at 90 Hz. The plasma emission was coupled into the optical fiber of a high-resolution intensified charge-coupled device (ICCD)-echelle spectrometer. Timeresolved characteristics of the laser-produced plasmas showed that the best results were obtained with delay times between 80 and 120 ns. Data obtained indicate both that it is a matrix-independent sampling process and that fs-LIBS can be used for the determination of Ca, Cu, Fe, K, Mg, Na, and P, but efforts must be made to obtain more appropriate detection limits for Al, Sr, and Zn.

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Section: Methodsmentioning

confidence: 99%

Evaluation of Femtosecond Laser-Induced Breakdown Spectroscopy for Analysis of Animal Tissues

et al. 2008

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“…A moagem criogênica, introduzida por Iyengar e Kasperek em 1977 23 , tem como princípio fundamental o aumento da dureza do material e inserção de falhas na estrutura cristalina, que facilitam o processo de moagem 23,24 . Desde a sua proposição, a moagem criogênica tem sido intensamente empregada para moer diferentes tipos de amostras 21,25,26 . Outros moinhos mecânicos como de almofariz e pistilo, de blenda, de disco, de facas e de bolas têm sido aplicados para moer amostras.…”

Section: Preparo Da Amostra Para Ss Gf Aasunclassified

Análise direta de sólidos por espectrometria de absorção atômica com atomização em forno de grafite: uma revisão

Nomura¹,

Silva²,

Oliveira³

2008

Quím. Nova

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“…This sample was identified as number 2. Samples were oven-dried at 60 o C for 12 h. [11][12][13] The studied sample digestion procedures are described below.…”

Section: Sample Preparation Procedures and Measurementsmentioning

confidence: 99%

Comparative studies of the sample decomposition of green and roasted coffee for determination of nutrients and data exploratory analysis

Filho¹,

Polito²,

Neto³

2007

J. Braz. Chem. Soc.

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Os teores de vários nutrientes foram determinados em 35 amostras de cafés verdes e torrados, por espectrometria de absorção atômica em chama (Ca, Mg, Fe, Cu, Mn e Zn), fotometria de emissão atômica em chama (Na e K) e pelo método Kjeldahl (N) após preparação das amostras por dois procedimentos de decomposição via úmida: i) sistema aberto (bloco digestor) e ii) sistema fechado (forno de microondas convencional com controle de pressão e temperatura). A exatidão dos procedimentos foi verificada analisando-se três materiais de referência certificados do National Institute of Standards and Technology (SRM 1573a Folha de Tomateiro; SRM 1547 Folha de Pessegueiro; SRM 1570a Espinafre). A análise dos dados após a aplicação do teste-t mostrou que os resultados obtidos no procedimento que empregou decomposição assistida por microondas em frascos fechados foram mais exatos do que os obtidos por bloco digestor com frascos abertos no nível de 95% de confiança. Além da exatidão, outras características favoráveis encontradas foram menores valores de branco analíticos, menor consumo de reagentes e menor tempo de decomposição das amostras. Análises exploratórias dos dados empregando-se Análise por Componentes Principais (PCA) e Análise por Agrupamentos Hierárquicos (HCA) mostraram que os elementos Na, K, Ca, Cu, Mg e Fe foram os principais responsáveis na diferenciação das amostras de cafés verde e torrado.The contents of some nutrients in 35 Brazilian green and roasted coffee samples were determined by flame atomic absorption spectrometry (Ca, Mg, Fe, Cu, Mn, and Zn), flame atomic emission photometry (Na and K) and Kjeldahl (N) after preparing the samples by wet digestion procedures using i) a digester heating block and ii) a conventional microwave oven system with pressure and temperature control. The accuracy of the procedures was checked using three standard reference materials (National Institute of Standards and Technology, SRM 1573a Tomato Leaves, SRM 1547 Peach Leaves, SRM 1570a Trace Elements in Spinach). Analysis of data after application of t-test showed that results obtained by microwave-assisted digestion were more accurate than those obtained by block digester at 95% confidence level. Additionally to better accuracy, other favorable characteristics found were lower analytical blanks, lower reagent consumption, and shorter digestion time. Exploratory analysis of results using Principal Component Analysis (PCA) and Hierarchical Cluster Analysis (HCA) showed that Na, K, Ca, Cu, Mg, and Fe were the principal elements to discriminate between green and roasted coffee samples. Keywords: sample preparation, coffee, nutrients, exploratory analysis IntroductionCoffee is an important commodity due to the high consumption of its beverage by people worldwide.1 Since the value of coffee beans is based on quality, producers and traders have been motivated to make use of extra tools in order to confirm the geographic origin of the coffee. 2,3 In this context, inorganic chemical analyses of green and roasted coffees may be used to a...

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Determination of Cd and Pb in food slurries by GFAAS using cryogenic grinding for sample preparation

Cited by 64 publications

References 38 publications

Evaluation of Femtosecond Laser-Induced Breakdown Spectroscopy for Analysis of Animal Tissues

Evaluation of Femtosecond Laser-Induced Breakdown Spectroscopy for Analysis of Animal Tissues

Análise direta de sólidos por espectrometria de absorção atômica com atomização em forno de grafite: uma revisão

Comparative studies of the sample decomposition of green and roasted coffee for determination of nutrients and data exploratory analysis

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