Optimization of arsine generation in atomic absorption arsenic determinations

Siemer, Darryl D.; Koteel, Prabhakaran; Jariwala, Vibhakar.

doi:10.1021/ac60370a026

Cited by 65 publications

(21 citation statements)

References 13 publications

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“…The effect of oxygen on the atomization of As and Sb hydrides in the heated quartz tubes was first reported by Gouldden et al 164 They reported that an increase in the sensitivity could be obtained if oxygen was added to the purge gas. Similarly, Siemer et al 172 based on their studies on the optimization of arsine generation in flame-in quartz tube atomizers, found that the sensitivity could be increased by using hydrogen for stripping the arsine, rather than using argon or nitrogen. According to Siemer et al, 172 carrier gases like Ar and N2 dilute the analyte atoms within the atomizer, but no reason was given for the observed sensitivity increase.…”

Section: ·3 Free Radical Mechanismmentioning

confidence: 99%

“…Similarly, Siemer et al 172 based on their studies on the optimization of arsine generation in flame-in quartz tube atomizers, found that the sensitivity could be increased by using hydrogen for stripping the arsine, rather than using argon or nitrogen. According to Siemer et al, 172 carrier gases like Ar and N2 dilute the analyte atoms within the atomizer, but no reason was given for the observed sensitivity increase.…”

Section: ·3 Free Radical Mechanismmentioning

confidence: 99%

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Mechanism of Volatile Hydride Formation and Their Atomization in Hydride Generation Atomic Absorption Spectrometry

Kumar

Riyazuddin

2005

ANAL. SCI.

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The mechanism of volatile hydride generation (HG) and the formation of analyte atoms in the quartz cell atomizer used in the determination of hydride-forming elements (As, Bi, Ge, Pb, Sb, Sn, Te etc.) by atomic absorption spectrometry (AAS), have been critically reviewed. The nascent hydrogen mechanism failed to explain hydride generation under different experimental conditions when tetrahydroborate (THB), amineboreanes (AB) and cyanotrihydroborate (CBH) were used as reductants. Various experimental evidence suggested a non-nascent hydrogen mechanism, in which the transfer of hydrogen directly bonded to boron to an analyte takes place. In electrochemical hydride generation (EcHG), the reduction of the analyte species and subsequent hydrogenation was proposed. The mechanism of analyte atom formation in a quartz tube atomizer has been explained by the following hypotheses: thermal decomposition, oxidation by 02 and collisions by hydrogen free radicals. The free-radical mechanism satisfactorily explains most of the analytical implications. The significant variation in the experimental conditions required to generate different analyte hydrides makes it difficult to arrive at a generalized mechanism of hydride formation.

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Section: ·3 Free Radical Mechanismmentioning

confidence: 99%

Section: ·3 Free Radical Mechanismmentioning

confidence: 99%

Mechanism of Volatile Hydride Formation and Their Atomization in Hydride Generation Atomic Absorption Spectrometry

Kumar

Riyazuddin

2005

ANAL. SCI.

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“…A atomização do hidreto dá-se nesta chama interna. Este sistema foi descrito pela primeira vez por Siemer 56 e seu modelo, combinado com chama oxigênio-hidrogênio 57 ou ar-hidrogênio 58 , foi adotado por outros autores, sem ou com algumas modificações 53,57,[59][60][61][62][63][64][65][66] . Matousek et al 67,68 propuseram um tubo de quartzo com micro-chama múltipla para a determinação de As, Se e Sb.…”

Section: Atomização Em Tubo Com Chama Internaunclassified

A geração química de vapor em espectrometria atômica

et al. 2002

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Recebido em 17/9/01; aceito em 29/5/02 CHEMICAL VAPOR GENERATION IN ATOMIC SPECTROMETRY. The historical development of atomic spectrometry techniques based on chemical vapor generation by both batch and flow injection sampling formats is presented. Detection via atomic absorption spectrometry (AAS), microwave induced plasma optical emission spectrometry (MIP-OES), inductively coupled plasma optical emission spectrometry (ICP-OES) , inductively coupled plasma mass spectrometry (ICP-MS) and furnace atomic nonthermal excitation spectrometry (FANES) are considered. Hydride generation is separately considered in contrast to other methods of generation of volatile derivatives. Hg -CVAAS (cold vapor atomic absorption spectrometry) is not considered here. The current state-of-the-art, including extension, advantages and limitations of this approach is discussed.Keywords: chemical vapor generation; atomic spectrometry; batch and flow injection. INTRODUÇÃOO sucesso da espectrometria atômica depende, freqüentemente, do procedimento de introdução da amostra, sendo que o modo mais comum baseia-se na formação de um aerossol líquido, por meio de nebulizadores pneumáticos. Esses dispositivos são de operação simples e conveniente e, por isso mesmo, amplamente utilizados. Entretanto, menos de 10% da solução introduzida é transformada em aerossol útil, sendo sua maior parte, portanto, descartada. Além disso, dificuldades com esses nebulizadores surgem quando são usadas soluções muito viscosas ou com alto teor salino ou, ainda, quando se dispõe tão somente de micro-volumes de amostra 1 .Uma alternativa que se apresenta é a transformação da espécie de interesse em um composto volátil, e seu posterior transporte para a célula de atomização. Quando esta transformação se faz por meio de uma reação química, o processo é conhecido como geração química de vapor. A geração eletroquímica também é citada, embora menos freqüentemente 2-7 . Dois trabalhos podem ser considerados como marcos na geração química de vapor: no primeiro, Hatch e Ott 8 inauguraram a técnica hoje conhecida como "de vapor frio", embora se deva citar os trabalhos anteriores de Poluektov et al. 9,10 Na técnica do vapor frio, o íon mercúrico contido numa solução da amostra é reduzido a mercúrio elementar e assim carreado por uma corrente de gás (ar, N 2 ou Ar), borbulhada através da solução, para a célula de absorção; ou seja, o vapor formado pela reação já é o próprio vapor atômico. O segundo marco na geração de vapor é o trabalho de Holak 11 , onde o arsênio foi reduzido a arsina pela adição, à amostra ácida, de Zn metá-lico, e esta transportada para a chama de um aparelho de absorção atômica. O ganho em sensibilidade observado resulta da maior eficiência de transporte do analito, em comparação com a nebulização pneumática, uma vez que toda a arsina formada pode, em princípio, alcançar o atomizador, carreada por um fluxo de argônio ou nitrogênio e também pelo próprio gás hidrogênio gerado na reação. Entretanto, a atomização do arsênio usando chama convencional apresenta ...

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“…Therefore, arsenic can be more readily accumulated into hair and nail than other tissues. 2 Some analytical methods have been used for trace determination of arsenic such as: Colorimetry, 3,4 Atomic Absorption Spectrometry, 4,5 hydride generation system combined with Atomic Absorption Spectrometry, 6 inductively coupled plasma mass spectrometry. 7,8 and Atomic Fluorescence Spectrometry.…”

Section: Introductionmentioning

confidence: 99%

Direct Determination of Arsenic in Beet Sugar Molasses Using Nickel as Chemical Modifier by Electrothermal Atomic Absorption Spectrommetry

Pourhossein

Shahlaei

2012

J Chinese Chemical Soc

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A simple electrothermal atomic absorption spectrometric (ETAAS) method is described for direct determination of arsenic in sugar beet molasses samples. Pyrolytic graphite tubes were used as atomizers. The compression between modifiers such as nickel nitrate, palladium nitrate and the mixture of palladium and magnesium nitrate were performed and nickel nitrate selected as the best chemical modifier. The effects of pyrolysis and atomization temperature were also studied and the pyrolysis temperature of 900°C and atomization temperature of 2300°C have been chosen for temperature program. The detection limit of the method was 1 ng/mL As in sugar beet molasses samples. The relative standard deviation for ten determination of a spiked sample with concentration of 50 ng/mL As was 2.4%. The accuracy of the method was confirmed by the analysis of spiked samples. The linear rang of calibration is in the range of 1-100 ng/mL of arsenic.

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Optimization of arsine generation in atomic absorption arsenic determinations

Cited by 65 publications

References 13 publications

Mechanism of Volatile Hydride Formation and Their Atomization in Hydride Generation Atomic Absorption Spectrometry

Mechanism of Volatile Hydride Formation and Their Atomization in Hydride Generation Atomic Absorption Spectrometry

A geração química de vapor em espectrometria atômica

Direct Determination of Arsenic in Beet Sugar Molasses Using Nickel as Chemical Modifier by Electrothermal Atomic Absorption Spectrommetry

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