Trace Elements in the Total Diet Typical of Northern Italy

Bettinelli, M.; Spezia, S.; Gatti, Anna; Ronchi, A.; Minoia, C; Roggi, Carla; Turconi, Giovanna Maria Clelia

doi:10.1002/9780470141007.ch10

Cited by 13 publications

(24 citation statements)

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“…[12][13][14] Em vista disso, a piroidrólise é uma das técnicas mais adequadas para o preparo de amostras inorgânicas, combustíveis fós-seis e, até mesmo, amostras biológicas, para a posterior determinação de halogênios, boro e enxofre. 12,15 A piroidrólise consiste na hidrólise de alguns elementos a elevadas temperaturas (~1000 °C) na presença de vapor d'água. Para fins analíticos, esta reação tem sido usualmente aplicada para o preparo de amostras sólidas, geralmente de materiais inorgânicos.…”

Section: Introductionunclassified

Preparo de amostras de combustíveis fósseis por piroidrólise para a determinação de flúor e cloro

Antes¹,

Duarte²,

Flores³

et al. 2010

Quím. Nova

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Recebido em 22/9/09; aceito em 16/12/09; publicado na web em 8/4/10 FLUORIDE AND CHLORIDE DETERMINATION IN FOSSIL FUELS AFTER SAMPLE PREPARATION BY PYROHYDROLYSIS. Pyrohydrolysis is proposed for fossil fuels sample preparation for further fluorine and chlorine determination. Samples were heated during 10 min at temperatures up to 1000 °C. Water vapor was passed through the reactor and the volatile products were condensed and collected in NH 4 OH solution. Fluoride was determined by potentiometry using an ion selective electrode (ISE) and Cl by ICP OES and DRC-ICP-MS. The results are in good agreement with certified values and the precision is better than 10% (n = 4). Sample preparation by means of pyrohydrolysis is relatively simple, whereas chlorine and fluorine can be determined at low concentrations.Keywords: pyrohydrolysis; halogens; fossil fuels. INTRODUÇÃOPetróleo e carvão são os principais combustíveis fósseis consumidos no mundo. A determinação de halogênios, especialmente flúor e cloro, nestes materiais é de grande importância, principalmente devido aos aspectos ambientais e industriais. A alta volatilidade destes halogênios, aliada ao elevado consumo de combustíveis fósseis, pode ocasionar a emissão de quantidades consideráveis destes elementos para o meio ambiente. Por outro lado, a presença destes elementos no petróleo, principalmente de sais de cloro, pode ocasionar severos problemas de corrosão dos equipamentos durante o processo de refino. Além disso, a presença de flúor e cloro também é indesejada em materiais onde é necessário elevado grau de pureza, como é o caso do coque de petróleo. Neste sentido, é indispensável o uso de métodos analíticos que permitam a determinação destes elementos com rapidez, exatidão e em baixas concentrações.1,2 O preparo de amostras com elevado teor de matéria orgânica, tais como carvão, petróleo e seus derivados, para a determinação de halogênios sempre foi considerado um desafio, principalmente devido à elevada volatilidade destes elementos e da possibilidade de contaminação. Quando é feita a decomposição da amostra com ácidos minerais, procedimento mais comumente empregado, estes elementos formam compostos voláteis, podendo levar a perdas dos analitos. Além disso, para a decomposição de carvão com elevado teor de sílica, geralmente é necessário o uso de ácido fluorídrico, o que inviabiliza a determinação de flúor.3 A piroidrólise também tem sido utilizada para o preparo de amostras de carvão para a posterior determinação de F, Cl, Br e I.4-10 Atualmente, a piroidrólise é recomendada pela American Society for Testing and Materials (ASTM) para a determinação de F em carvão.11 Além disso, o preparo de amostras de combustíveis fósseis à base de plutônio e urânio para a posterior determinação de boro, cloro e flúor, preparo de amostras de solo contaminado com combustíveis nucleares para posterior determinação de iodo e preparo de amostras biológicas e geológicas para a determinação de halogênios são outras aplicações recentes da piroidrólise.12-14 Em vista disso, a piro...

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Section: Introductionunclassified

Preparo de amostras de combustíveis fósseis por piroidrólise para a determinação de flúor e cloro

Antes¹,

Duarte²,

Flores³

et al. 2010

Quím. Nova

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“…The volatile halogen species evolved can be simply condensed 33,37 or collected in alkaline solutions such as Na 2 CO 3 , Na 2 CO 3 /NaHCO 3 and (NH 4 ) 2 CO 3 . 24,31 The purpose of the present work was to develop a method for F, Br and I determination in mineral supplements using pyrohydrolysis for sample preparation. Pyrohydrolysis was investigated in view of the difficulties associated with F, Br and I determination in such complex matrix.…”

Section: Introductionmentioning

confidence: 99%

“…Pyrohydrolysis is a simple alternative for decomposition of organic 7,19,31,33 and inorganic [34][35][36] materials when halogens determination is intended. The main advantages are the possibility of matrix separation and the use of a diluted alkaline solution for analytes absorbing.…”

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

“…20,21 Sample preparation is usually the bottleneck in halogen determination by ICP-MS, due to memory effects caused by high volatility of halogens in acidic solutions. [22][23][24] Therefore, alkaline fusion, 20 dilution or dispersion in alkaline solution, distillation (for fluorine), combustion in bombs, 25 microwave-induced combustion (MIC) 9,26-29 and pyrohydrolysis 7,17,[30][31][32] are used for sample preparation.Pyrohydrolysis is a simple alternative for decomposition of organic 7,19,31,33 and inorganic 34-36 materials when halogens determination is intended. The main advantages are the possibility of matrix separation and the use of a diluted alkaline solution for analytes absorbing.…”

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confidence: 99%

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Determination of bromine, fluorine and iodine in mineral supplements using pyrohydrolysis for sample preparation

Taflik

Duarte

Flores

et al. 2012

J. Braz. Chem. Soc.

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Neste trabalho foi utilizada a piroidrólise para a decomposição de suplemento mineral utilizado na nutrição animal, para a posterior determinação de F, Br e I. Flúor foi determinado por potenciometria utilizando eletrodo íon-seletivo para fluoreto, enquanto que Br e I foram determinados por espectrometria de massa com plasma indutivamente acoplado. Os principais parâmetros que influenciam a piroidrólise foram investigados e, após a devida avaliação dos mesmos, foram fixadas as seguintes condições: a temperatura do reator em 1000 °C durante 10 min; a proporção entre a massa de amostra e a massa de acelerador em 1 + 5 e a vazão do gás carreador em 200 mL min -1 . A exatidão do método foi avaliada usando teste de recuperação do analito e análise de materiais de referência certificados de rocha fosfática e de solo. O método foi aplicado para análise de suplemento mineral. Os limites de quantificação foram de 16, 0,3 e 0,07 µg g -1 para F, Br e I, respectivamente. Assim, usando-se um método relativamente simples e de baixo custo é possível a decomposição de até 5 amostras por hora. Portanto, a piroidrólise pode ser usada como um método de rotina para o preparo de amostra de suplemento mineral para a determinação de F, Br e I.Pyrohydrolysis was employed for mineral supplements decomposition prior to F, Br and I determination. Fluoride determination was carried out by potentiometry using a fluoride-ion selective electrode, whereas Br and I were determined by inductively coupled plasma mass spectrometry. The main parameters that influence on pyrohydrolysis were investigated. After evaluation, the following conditions were established: reactor temperature of 1000 °C during 10 min; sample plus accelerator mass ratio of 1 + 5 and carrier gas (air) flow rate of 200 mL min -1 . The accuracy of the proposed method was evaluated by analyte recovery tests and analysis of certified reference materials of phosphate rock and soil. Commercial mineral supplement samples were analyzed. The limits of quantification were 16, 0.3 and 0.07 µg g -1 for F, Br and I, respectively. By using a relatively simple and low cost pyrohydrolysis system up to 5 samples can be processed per hour. The developed sample preparation procedure can be routinely employed for F, Br and I determination in mineral supplements. Keywords: pyrohydrolysis, halogens determination, mineral supplement IntroductionSeveral elements are essential for animals growing and breeding. Those elements required in high amounts are called macronutrients (Ca, Cl, K, P, Mg, Na, and S) and those elements required in low concentrations are called micronutrients (Co, Cu, Fe, I, Mn, Mo, Se, Zn, and eventually Cr and F are included in this group). 1 The main functions of essential elements in the organism are associated to the structural composition of body and enzymatic and hormonal processes.Although F usually increases the strength of bones and teeth, this element is generally not considered as essential. 1 Fluorine is usually present as a contaminant since it is Taflik et al. 489 ...

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Comparison of inductively coupled plasma mass spectrometry techniques in the determination of platinum in urine: quadrupole vs. sector field

Spezia

Bocca

Forte

et al. 2005

Rapid Comm Mass Spectrometry

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In recent years the increasing use of platinum (Pt) both in medical and in industrial applications has caused its growing anthropogenic emission and spread in the environment. Pt is released into the atmosphere by exhaust catalytic converters, and Pt compounds are often used in antitumour therapies. As a consequence, significant amounts of Pt can be detected in hospital wastewaters. This can lead to an increase in the exposure levels to Pt, especially in urban areas. It is therefore necessary to determine Pt reference values in the general population, by using suitable procedures able to achieve adequate analytical performances. Several measurements of Pt in biological fluids have been reported, but the analytical methods used for the determination of Pt often lack information about the uncertainty of the results, especially for low concentrations of urinary Pt in non-occupationally exposed subjects. The present paper considers the measurement of urinary Pt levels in a general population group from central Italy, by both quadrupole (Q) and sector field (SF) inductively coupled plasma mass spectrometry (ICP-MS). The two procedures were validated and their expanded uncertainties were evaluated. The limits of detection (LODs), calculated taking into account dilution factors, were 0.18 and 0.05 ng L À1 of Pt for the Q and SF procedures, respectively.The median value observed was 4.13 ng L À1 of Pt in urine, while the relative combined uncertainty at 5 ng L À1 was below 20% with both ICP-MS techniques. These data are in good agreement with those reported in the literature for similar studies.

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Trace Elements in the Total Diet Typical of Northern Italy

Cited by 13 publications

References 0 publications

Preparo de amostras de combustíveis fósseis por piroidrólise para a determinação de flúor e cloro

Preparo de amostras de combustíveis fósseis por piroidrólise para a determinação de flúor e cloro

Determination of bromine, fluorine and iodine in mineral supplements using pyrohydrolysis for sample preparation

Comparison of inductively coupled plasma mass spectrometry techniques in the determination of platinum in urine: quadrupole vs. sector field

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