Fatemeh Nobakhti - Department of Chemistry, Varamin(Pishva) Branch Islamic Azad University, Varamin, Iran
Ali Moghimi - Department of Chemistry, Varamin(Pishva) Branch Islamic Azad University, Varamin, Iran
Elham Moniri - Department of Chemistry, Varamin(Pishva) Branch Islamic Azad University, Varamin, Iran

A new sensitive and simple method was developed for the preconcentration of trace amounts of Mo using 1-(2-pyridylazo)-2-naphthol (PAN) as chelating reagent prior to its determination by flame atomic absorption spectrometry. The proposed method is based on the utilization of a column packed with graphene as sorbent. Several effective parameters on the extraction and complex formation were selected and optimized. Under optimum conditions, the calibrationgraph was linear in the concentration range of 5.0–240.0 μg L-1 with a detection limit of 0.36 μg L-1. The relative standard deviation for ten replicate measurements of 20.0 and 100.0 μg L-1 of Mo were 3.45 and 3.18%, respectively. Comparative studies showed that graphene issuperior to other adsorbents including C18 silica, graphitic carbon, and single- and multi-walled carbon nanotubes for the extraction of Mo. The proposed method was successfully applied in the analysis of four real environmental water samples good spiked recoveries over the range of 95.8–98.6% were obtained

Graphene; Solid-phase extraction; Preconcentration; Flame atomic absorption spectrometry; Mo