Determination of arsenic based on quenching of CdS quantum dots fluorescence using the gas-diffusion flow injection method

Nutthaya Butwong; Tuanjai Noipa; Rodjana Burakham; Supalax Srijaranai; Wittaya Ngeontae

doi:10.1016/j.talanta.2011.05.023

Determination of arsenic based on quenching of CdS quantum dots fluorescence using the gas-diffusion flow injection method

Talanta. 2011 Aug 15;85(2):1063-9. doi: 10.1016/j.talanta.2011.05.023. Epub 2011 May 19.

Authors

Nutthaya Butwong¹, Tuanjai Noipa, Rodjana Burakham, Supalax Srijaranai, Wittaya Ngeontae

Affiliation

¹ Department of Chemistry and Center for Innovation in Chemistry, Faculty of Science, Khon Kaen University, Khon Kaen 40002, Thailand.

PMID: 21726739
DOI: 10.1016/j.talanta.2011.05.023

Abstract

A sequential injection analysis system for determination of arsenic based on hydride generation and fluorescence quenching of mercaptoacetic acid capped cadmium sulfide quantum dots (CdS-MAA QDs) is described. The generated arsine diffused across the PTFE membrane in a gas-diffusion unit and subsequently interacted with CdS-MAA QDs. The parameters affecting the arsine generation and the fluorescence quenching of QDs were studied. Under the optimum conditions, it was observed that a increase in the concentration of As(III) corresponded well to a decrease in fluorescence intensity according to the Stern-Volmer relationship. The extent of quenching was dependent on the concentration of arsenic in the range of 0.08-3.20 mmol L(-1), with the detection limit of 0.07 mg L(-1). The precision (%RSD) from eight replicates of the determination of As(III) 1.0 mg L(-1) was found to be 1.4%. The proposed method was applied to the determination of arsenic in ground water samples with satisfactory recoveries.

Publication types

Research Support, Non-U.S. Gov't