Application of Graphene as a Sorbent for the Preconcentration and Determination of Trace Amounts of Mercury in Water Samples by Hydride Generation Atomic Fluorescence Spectrometry.

The potential of graphene as a solid-phase extraction adsorbent for the separation and preconcentration of mercury (Hg) was investigated. Hg2+ was found to be quantitatively adsorbed onto graphene within pH 6.0-8.0, and then completely eluted with 4.0 mL of nitric acid/methanol (1:1, v/v) solution at a flow rate of 2.0 mL min-1. A new method using a microcolumn packed with graphene as a sorbent was developed for the preconcentration of trace amount of Hg2+ prior to its determination by hydride generation atomic fluorescence spectrometry. Under the optimum experimental conditions, the detection limit of this method for Hg2+ was 5.0 ng L-1, with an enrichment factor of 15.0, and the relative standard deviation was 3.5% at the 1.0 μg L-1 Hg2+ level. The method was then applied for the determination of trace amount of Hg2+ in water samples with satisfactory results. [ABSTRACT FROM AUTHOR]