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Titolo:
Determination of various arsenic species by flow injection hydride generation atomic absorption spectrometry: investigation of the effects of the acid concentration of different reaction media on the generation of arsines
Autore:
Carrero, P; Malave, A; Burguera, JL; Burguera, M; Rondon, C;
Indirizzi:
Univ Los Andes, Fac Sci, IVAIQUIM, Venezuelan Andean Inst Chem Res, Merida5101A, Venezuela Univ Los Andes Merida Venezuela 5101A t Chem Res, Merida5101A, Venezuela
Titolo Testata:
ANALYTICA CHIMICA ACTA
fascicolo: 1-2, volume: 438, anno: 2001,
pagine: 195 - 204
SICI:
0003-2670(20010703)438:1-2<195:DOVASB>2.0.ZU;2-I
Fonte:
ISI
Lingua:
ENG
Soggetto:
L-CYSTEINE; AUTOMATED-DETERMINATION; BIOLOGICAL SAMPLES; SPECIATION; REDUCTION; OPTIMIZATION; ENHANCEMENT; ANTIMONY; AAS;
Keywords:
arsenic; arsine generation atomic absorption spectrometry; flow injection; mechanisms; L-cysteine; mercaptoacetic acid;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Physical, Chemical & Earth Sciences
Citazioni:
29
Recensione:
Indirizzi per estratti:
Indirizzo: Carrero, P Univ Los Andes, Fac Sci, IVAIQUIM, Venezuelan Andean Inst Chem Res, POB 542, Merida 5101A, Venezuela Univ Los Andes POB 542 Merida Venezuela 5101A 5101A, Venezuela
Citazione:
P. Carrero et al., "Determination of various arsenic species by flow injection hydride generation atomic absorption spectrometry: investigation of the effects of the acid concentration of different reaction media on the generation of arsines", ANALYT CHIM, 438(1-2), 2001, pp. 195-204

Abstract

An on-line how injection hydride generation atomic absorption spectrometry(FI-HG-AAS) system was developed to study the effect of acid concentrationon the arsine generation from arsenite (As(III)), arsenate (As(V)), monomethylarsonic acid (MMAA) and dimethylarsinic acid (DMAA) pretreated in different reaction media. The signals for the arsines generated from MMAA and DMAA prepared in aqueous pure medium substantially decreased at hydrochloric acid concentrations higher than 2 mol l(-1). Neutralization of the acid in the reaction mixture after the HG process did not produce any appreciable effect on the arsine signals. When the arsenic species were prereduced with L-cysteine or mercaptoacetic acid to yield thiolate complex of As(III), thearsines generated produced different response profiles compared to those obtained in pure aqueous medium. In this case, similar maximum signals were obtained within a narrow range at low acid concentrations (from 0.06 to 0.12 mol l(-1)); thereafter a sharp decrease of the signals at hydrochloric acid concentrations around 1 mol l(-1), followed by a sharp increase to reacha constant value at higher and different acid concentrations. These results might suggest two mechanisms for the arsine generation: (i) at low acid concentrations, the thiolate complexes of As(m) are rapidly converted into the respective arsines by BH4- and (ii) at high acid concentrations, the arsines are generated by the action of nascent hydrogen produced by the decomposition of BH4-. (C) 2001 Elsevier Science B.V. All rights reserved.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 31/03/20 alle ore 21:27:44