Solid - phase extraction of Lead in saline matrix using by GF- AAS with multivariate optimization

Abstract

This work presents a novel method investigated in the pre-concentration of lead ion as well as the matrix effect eliminated in high salinity medium using solid phase extraction by graphite furnace Atomic Absorption spectroscopy (GFAAS). Fe 3 O 4 -graphene was used as the sorbent while 1M HNO 3 was used as the extraction solvent. Parameters such as: pH, amount of sorbent, time of adsorption, time of desorption and, stirring rate affecting the extraction efficiency of the method were studied and optimized by utilizing two decent optimization methods; factorial design and central composite design (CCD). The limit of detection and limit of quantification were 4.4 and 14.8 ng/mL, respectively The accuracy of the method was evaluated by analyzing a spiked real sample. Good spiked recoveries over the range 98.8-103.6 % were obtained. Under the optimum conditions, the calibration graph was linear over the range 5-50 ng/mL. The relative standard deviation was 4.4 % for four repeated determinations at a concentration of 20 ng/mL.