A Multi-Element Ion-Pair Extraction for Trace Metals Determination in Environmental Samples

A multi-element ion-pair extraction method was described for the preconcentration of Cd(II), Co(II), Cr(III), Cu(II), Fe(III), Mn(II), Ni(II), Pb(II), and Zn(II) ions in environmental samples prior to their determinations by flame atomic absorption spectrometry (FAAS). As an ion-pair ligand 2-(4-methoxybenzoyl)-N'-benzylidene-3-(4-methoxyphenyl)-3-oxo-N-phenyl-propono hydrazide (MBMP) was used. Some analytical parameters such as pH of sample solution, amount of MBMP, shaking time, sample volume, and type of counter ion were investigated to establish optimum experimental conditions. No interferences due to major components and some metal ions of the samples were observed. The detection limits of the proposed method were found in the range of 0.33-0.9 mu g L-1 for the analyte ions. Recoveries were found to be higher than 95% and the relative standard deviation (RSD) was less than 4%. The accuracy of the procedure was estimated by analyzing the two certified reference materials, LGC6019 river water and RTC-CRM044 soil. The developed method was applied to several matrices such as water, hair, and food samples.