Graphene-Based Solid-Phase Extraction for a Sensitive Determination of Trace Amounts of Lead in Water Samples

Abstract

Graphene, a novel class of carbon nanostructures, has great promise for use as sorbent materials because of its ultrahigh specific surface area. A new method using a column packed with gaphene as sorbent was developed for the preconcentration of trace amounts of lead (Pb) prior to its determination by flame atomic absorption spectrometry. Some effective parameters on the extraction and complex formation were selected and optimized. Under optimum conditions, an enrichment factor of 250 was obtained. The calibration graph was linear in the concentration range of 2.4x 10.8 mol L-1-2.9x 10.6 mol L-1 with a detection limit of 1.9x 10.9 mol L-1. The relative standard deviation for ten replicate measurements of 9.7x 10.8 mol L-1 and 1.4x 10.6 mol L-1 of Pb were 3.45 %and 3.28 %, respectively. The proposed method was successfully applied in the analysis of four real environmental water samples and good spiked recoveries over the range of 95.5–99.6 %were obtained. This work not only proposes a useful method for environmental water sample pretreatment, but also reveals the great potential of gaphene as an excellent sorbent material in analytical processes.