Optimization of dispersive liquid-liquid microextraction followed by flame atomic absorption determination of Cu (II), Ni (II) and Co (II) based on the complexation reaction with phenathrene-9, 10-dine dioxime (PD)

Abstract

In this study, a dispersive liquid-liquid microextraction (DLLME) method was used for preconcentration of Cu (II), Ni (II) and Co (II) cations from water samples. Oxime (phenathrene-9, 10-dine dioxime (PD)) was used as a chelating agent prior to extraction. Flame atomic absorption spectrophotometry using an acetylene-air flame was used for quantitation of the analytes after preconcentration. The effects of various experimental parameters in extraction were investigated using two optimization methods, one variable at a time and central composite design. The experimental design was done at four levels of operating parameters. Under optimum conditions the calibration curves were linear in the range of (10-2000μg L^-1) with detection limits of 5 μg L^-1 for both Cu (II) and Ni (II) (10-1000 μgL ^-1) and 0.5 μg L ^-1 for Co (II).  Recoveries and enrichment factores for Copper, Cobalt and Nickel were obtained as (77.6%, 26.99), (76.53%, 29.95) and (74.23%, 29), respectively.