Condensation cascades and methylgroup transfer reactions during the formation of arsane, methyl- and dimethylarsane by aqueous borohydride and (methyl) arsenates

Abstract

Access and use of this website and the material on it are subject to the Terms and Conditions set forth at Condensation cascades and methylgroup transfer reactions during the formation of arsane, methyl-and dimethylarsane by aqueous borohydride and (methyl) arsenates D'Ulivo, Alessandro; Meija, Juris; Mester, Zoltán; Pagliano, Enea; Sturgeon, Ralph E.http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/jsp/nparc_cp.jsp?lang=fr L'accès à ce site Web et l'utilisation de son contenu sont assujettis aux conditions présentées dans le site LISEZ CES CONDITIONS ATTENTIVEMENT AVANT D'UTILISER CE SITE WEB. NRC Publications Record / Notice d'Archives des publications de CNRC:http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/ctrl?action=rtdoc&an=21268282&lang=en http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/ctrl?action=rtdoc&an=21268282&lang=fr READ THESE TERMS AND CONDITIONS CAREFULLY BEFORE USING THIS WEBSITE.http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/jsp/nparc_cp.jsp?lang=en Vous avez des questions? Nous pouvons vous aider. Pour communiquer directement avec un auteur, consultez la première page de la revue dans laquelle son article a été publié afin de trouver ses coordonnées. Si vous n'arrivez pas à les repérer, communiquez avec nous à PublicationsArchive-ArchivesPublications@nrc-cnrc.gc.ca. Questions? Contact the NRC Publications Archive team atPublicationsArchive-ArchivesPublications@nrc-cnrc.gc.ca. If you wish to email the authors directly, please see the first page of the publication for their contact information. NRC Publications Archive Archives des publications du CNRCThis publication could be one of several versions: author's original, accepted manuscript or the publisher's version. / La version de cette publication peut être l'une des suivantes : la version prépublication de l'auteur, la version acceptée du manuscrit ou la version de l'éditeur. For the publisher's version, please access the DOI link below./ Pour consulter la version de l'éditeur, utilisez le lien DOI ci-dessous.http://doi.org/10.1007/s00216-011-5503-4Analytical and Bioanalytical Chemistry, 402, 2, pp. 921-933, 2011-10-30 ABSTRACTThe formation of volatile products during the reaction of As(III), As(V), MeAsO(OH) 2 and Me 2 AsO(OH) with aqueous NaBH 4 has been investigated and the formation of arsanes, di-and triarsanes has been detected . The presence of triarsanes is reported here for the first time. Di-and triarsanes are likely formed in condensation cascade reactions, whereas trimethylarsane arises via the transfer of a methyl group. The formation of volatile byproducts is considerably reduced by increasing the acidity of the medium and the concentration of NaBH 4 or by the addition of thiols, such as cysteine. A reaction scheme is proposed which reconciles the evidence reported herein and elsewhere in the literature that is valid for both analytical (trace analysis) and non-analytical reaction conditions.

The Binomial Distribution of Hydrogen and Deuterium in Arsanes, Diarsanes, and Triarsanes Generated from As(Iii)/[BHnD4-n]− and the Effect of Trace Amounts of Rh(Iii) Ions

“…The binomial distribution originates from the multistep hydrogen transfer, as outlined for diarsane in Figure 4. The trends observed in the composition of diarsane and triarsane follow the hypothesis of a concerted multistep formation of arsane in a fashion already demonstrated for AsH 3 [11], and they further validate the proposed condensation cascade mechanism [14]. Therefore, the formation of di-and triarsanes can be described as a combination of two independent events: condensation of two hydroxoarsanes and their reduction by borohydrides via the concerted transfer of hydrogen to the arsenic substrate, as summarized in Scheme 1.…”

“…The stoichiometry of the above reaction is respected only when arsenic compounds are present at trace levels in an excess of boranes (i.e., under analytical conditions). When the concentration of arsenic rises above the millimolar level, however, a complex set of side reactions takes place [14] with formation of condensation products:…”

“…This mechanism, however, is strongly altered in the presence of noble metals such as Au(III), Pd(II), and Pt(II)-their action on hydride generation cannot be completely explained as causing a decrease in the amount of hydride generated (yield interference) [12]; they play an active role in the transfer of hydrogen from [BH 4 ] − to the arsenic (mechanistic interference) [13]. Furthermore, another source of complexity in the formation of arsane arises due to condensation reactions that occur at high substrate concentration; the formation of polyarsanes, such as diarsane (As 2 H 4 ) and triarsane (As 3 H 5 ), is due to a reaction of the form [14]: R 1 R 2 À As À OH þ H À As À R 3 R 4 ! R 1 R 2 À As À As À R 3 R 4 þ H 2 O:…”

Inorganic Arsenic Determination in Food: A Review of Analytical Proposals and Quality Assessment Over the Last Six Years

“…Thus, Wu et al 122 review the application of several reducing systems other than tetrahydroborate; while D'Ulivo et al 126 discuss the mechanisms of hydrides forming from iAs and from methylated arsenic species, by using NaBH 4 and the formation of intermediate by-products. Anawar 127 discusses the advantages and disadvantages of the combined HG-ETAAS system, in a review focused on this combined technique applied to arsenic speciation.…”

Comment on “Understanding the effects of potassium ferricyanide on lead hydride formation in tetrahydroborate system and its application of lead in milk using hydride generation inductively coupled plasma optical emission spectrometry” by B. Deng, X. Xu, Y. Xiao, P. Zhu, Y. Wang

“…More recently, further mass spectrometric evidences [9][10][11] on arsane and methylarsane generation showed that approaching the low THB/analyte ratio, typical of "synthetic-like" conditions, several polymeric arsanes could be identified both in vapor and liquid phase and precipitation of a large mass fraction of the analyte is observed at the higher analyte concentrations employed. In the case of lead this effect could be also magnified by the change of structure of lead substrates reacting with THB, in view of the significant change of speciation of aqueous lead ions passing from micromolar to millimolar level total lead ( Fig.…”