Characterization and application of silylated substrates for the preconcentration of cations

Leyden, Donald E.; Luttrell, G. Howard.; Sloan, A. Elizabeth; Deangelis, Nicholas J.

doi:10.1016/s0003-2670(01)82843-9

Cited by 122 publications

(40 citation statements)

References 3 publications

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“…Third subjects are the notably high µmol g −1 values determined for chemically MWCNTs-Hisphase in comparison with values found as given in Table 1. The comparison between the metal sorption properties of chemically and physically-MWCNTs-His phases has been extensively studied (Leyden et al, 1976b) and the results presented in this work are consistent with the surface activity of the donor atoms responsible for metal ion interaction, sorption, extraction and selective removal. In the case of the physically adsorbed phase, some of these donor atoms are involved in physical adsorption processes with the active surface, leading to the minimization of the reactivity of such donor atoms for metal interaction and binding processes.…”

Section: Metal Capacity In Various Controlling Factorssupporting

confidence: 82%

“…The percentage removal of metal ions from aqueous solutions is essential for the evaluation of the method described and suggested here. This is mainly dependent on several well known factors such as the type and amount of packing stationary and mobile phases and the Percentage removal 10 500 96 ± 2 50 500 97 ± 3 100 500 97 ± 5 10 1000 98 ± 3 50 1000 99 ± 2 100 1000 98 ± 3 flow rate of the mobile phase (Leyden et al, 1976b). In this study, we attempted to evaluate the percentage recovery of Hg(II) with different spiked concentrations, namely 10, 50 and 100 ng ml −1 from 1 L of 0.1 M NaOAc solution by the application of two different amounts (500 and 1000 mg) of MWCNTs-His phase packing.…”

Section: Percentage Removal Of Hg(ii) From Aqueous Solutionmentioning

confidence: 99%

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Preconcentration and determination of Mercury(II) from natural water and milk sample by Histidine functionalized multi-walled carbon nanotubes (MWCNTs-His)

Moghimi¹,

Mazloumifar²

2013

Afr. J. Pure Appl. Chem.

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Section: Metal Capacity In Various Controlling Factorssupporting

confidence: 82%

Section: Percentage Removal Of Hg(ii) From Aqueous Solutionmentioning

confidence: 99%

Preconcentration and determination of Mercury(II) from natural water and milk sample by Histidine functionalized multi-walled carbon nanotubes (MWCNTs-His)

Moghimi¹,

Mazloumifar²

2013

Afr. J. Pure Appl. Chem.

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“…8-hydroxyquinoline 22 (oxine) is a well-charac-terized and versatile chelating organic ligand which can form covalent compounds with a number of metal ions under controlled pH. It has been immobilized on a variety of supports such as glass beads 23 , silica gel 24 , polystyrene divinylbenzene 25 , silicon tube 26 , and ionic imprinted polymer 27 ; thus becoming suitable to be used with sorbents in metal analysis.…”

Section: Introductionmentioning

confidence: 99%

Cadmium and lead in seafood samples determined by solid phase extraction and graphite furnace atomic absorption spectrometry

Chooto¹,

Innuphat²,

Wararattananurak³

et al. 2015

ScienceAsia

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ABSTRACT:A sample preparation method has been developed to detect cadmium and lead in commercial frozen seafood samples. After being digested with concentrated HNO 3 in a closed polypropylene vessel, the clear sample solution was separated and preconcentrated by solid phase extraction using octadecyl silica membrane discs modified with 8-hydroxyquinoline prior to determination by graphite furnace atomic absorption spectrometry (GFAAS). The preconcentration conditions including pH, ligand quantity, eluent concentration, and volume were found to be effective with 10.0 mg of 8-hydroxyquinoline in 2.0 ml ethanol and pH 6.0. The retained cadmium and lead were efficiently eluted with 5.0 ml of 1.0 M HNO 3 and determined by GFAAS. The detection limits for cadmium and lead were 0.073 µg/l and 0.332 µg/l, respectively. The proposed method was tested with the certified reference material, DORM-2 (Dogfish muscle), with good agreement. The recoveries were found to be 100-103% (n = 4) for Cd and 92-108% (n = 5) for Pb with relative standard deviation (n = 5) of 3% for Cd and 4% for Pb. The extraction was found to be unaffected by coexisting ions. The method was applied satisfactorily to the seafood samples and trace levels of cadmium and lead were found.

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“…Esses conjuntos de propriedades são requisitos importantes para a ação específica do material modificado com finalidades analíticas, o que, em muitos casos, é o objetivo procurado. Assim, do ponto de vista da química de coordenação, idealizam-se agentes com uma diversidade de funções de forma que as moléculas formadas possam atuar com grande atividade, no sentido de agir como quelantes na retirada de cátions de um meio e, de preferência, com alta seletividade 28,29 . Nesta perspectiva, este trabalho teve como objetivo estudar a adsorção de cátions divalentes, tais como Cu, Ni e Co, em um híbri-do orgânico-inorgânico de sílica gel influenciada pelo pH e força iônica.…”

Section: Introductionunclassified

Quimissorção de cátions divalentes em sílica gel modificada com ácido tioglicólico: a influência do pH e força iônica

Sousa¹,

Filha²,

Pinto³

et al. 2007

Quím. Nova

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Recebido em 6/1/06; aceito em 4/8/06; publicado na web em 22/2/07 CHEMISORPTION OF DIVALENT CATIONS ON A SILICA GEL SURFACE MODIFIELD WITH THIOGLYCOLIC ACID -pH INFLUENCE AND IONIC STRENGTH. A novel type of heavy metal adsorbent was prepared by the covalent grafting of thioglycolic acid molecules on a silica gel surface previsiouly modified with 3-aminopropyltrimethoxysilane. The amount of thioglycolic acid immobilized was 1.03 mmol per gram of silica. This material displayed a chelating moiety containing nitrogen, sulfur, and oxygen basic centers which are potentially capable of extracting from aqueous solutions cations such as Cu(II), Ni(II), Co(II), influenced by pH and ionic strength. This process of extraction was carried out by the batch method when similar chemisorption isotherms were observed for all cations. A modified Langmuir equation describes the experimental data.Keywords: silica gel; chemisorption; thioglycolic acid. INTRODUÇÃONos últimos anos, o estudo das propriedades de superfície de sólidos inorgânicos, principalmente o dos porosos, tem aumentado consideravelmente, conforme a quantidade de trabalhos que vêm sendo desenvolvidos, visando a modificação físico-química da superfície desses sólidos e a dotação de propriedades específicas. O que atrai os pesquisadores, para modificarem estas superfícies aparentemente inertes, é aproveitarem-se dessas propriedades físicas e químicas específicas, para tornar possível o uso dos sólidos modificados em diversas aplicações tecnológicas. O interesse nesses materiais deve-se à diversidade de aplicações encontradas nos vários campos da ciência, dentre as quais, podem ser citadas a adsorção de espécies catiônicas, utilizada na retirada de íons metálicos de solução com baixíssima concentração de soluto, na ordem de ng/mL 1,2 ; o transporte de enzimas 3,4 ; a concentração de traços de cátions metáli-cos a partir de água do mar ou de efluentes [5][6][7][8][9][10] ; os trocadores de íons; o uso catalítico 11 e, a aplicação em cromatografia. Os sólidos modificados para se obterem novos adsorventes envolvem materiais, tais como sílica gel 12-14 , os filissilicatos 15 fibras de carvão ativado, quitosana natural 16 , crisotila 17 , vermiculita 18 , fulerenos e heterofulerenos. Os materiais sintetizados desta forma são efetivamente utilizados para remoção de íons metálicos tóxi-cos específicos em meio aquoso [19][20][21][22] . A sílica é muito utilizada por apresentar distintas vantagens sobre os suportes orgânicos. Neste sentido, alguns aspectos merecem destaque: a imobilização em sílica pode ser feita por uma variedade de agentes sililantes 23,24 , permitindo a obtenção de diferentes grupos funcionais pendentes; a sílica não sofre inchamento e oferece grande resistência a solventes orgânicos 25 e, uma importante propriedade está associada à alta estabilidade térmica 26,27 . Esses conjuntos de propriedades são requisitos importantes para a ação específica do material modificado com finalidades analíticas, o que, em muitos casos, é o objetivo procurado. Assim, do ponto...

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Characterization and application of silylated substrates for the preconcentration of cations

Cited by 122 publications

References 3 publications

Preconcentration and determination of Mercury(II) from natural water and milk sample by Histidine functionalized multi-walled carbon nanotubes (MWCNTs-His)

Preconcentration and determination of Mercury(II) from natural water and milk sample by Histidine functionalized multi-walled carbon nanotubes (MWCNTs-His)

Cadmium and lead in seafood samples determined by solid phase extraction and graphite furnace atomic absorption spectrometry

Quimissorção de cátions divalentes em sílica gel modificada com ácido tioglicólico: a influência do pH e força iônica

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