Document Type

Journal Article

Department/Unit

Department of Chemistry

Title

Toward the use of surface modified activated carbon in speciation: Selective preconcentration of selenite and selenate in environmental waters

Language

English

Abstract

This paper describes a novel application of tetrabutylammonium hydroxide-modified activated carbon (AC-TBAH) to the speciation of ultra-trace Se(IV) and Se(VI) using LC-ICP-DRC-MS. The anion exchange functionality was immobilized onto the AC surface enables selective preconcentration of inorganic Se anions in a wide range of working pHs. Simultaneous retention and elution of both analytes, followed by subsequent analysis with LC-ICP-DRC-MS, allows to accomplish speciation analysis in natural samples without complicated redox pre-treatment. The laboratory-made column of immobilized AC (0.4g of sorbent packed in a 6mL syringe barrel) has achieved analyte enrichment factors of 76 and 93, respectively, for Se(IV) and Se(VI), thus proving its superior preconcentration efficiency and selectivity over common AC. The considerable enhancement in sensitivity achieved by using the preconcentration column has improved the method's detection limits to 1.9-2.2ngL-1, which is a 100-fold improvement compared with direct injection. The analyte recoveries from heavily polluted river matrix were between 95.3 and 107.7% with less than 5.0% RSD. The robustness of the preconcentration and speciation method was validated by analysis of natural waters collected from rivers and reservoirs in Hong Kong. The modified AC material is hence presented as a low-cost yet robust substitute for conventional anion exchange resins for routine applications. © 2011 Elsevier B.V.

Keywords

Activated carbon, LC-ICP-MS, Preconcentration, Selenium, Speciation

Publication Date

2011

Source Publication Title

Journal of Chromatography A

Volume

1218

Issue

16

Start Page

2160

End Page

2164

Publisher

Elsevier

DOI

10.1016/j.chroma.2011.02.016

ISSN (print)

00219673

ISSN (electronic)

18733778

This document is currently not available here.

Share

COinS