Preconcentration of trace elemets on amberlite XAD-4 resin functionalised with 1,2- bis (0-aminophenylthio) ethane and their determination by FAAS in environmental samples

Abstract

The use of chemically modified XAD-4-1,2-bis (o-aminophenylthio) ethane chelating resin for preconcentrating $Cr^{6+}$, $Mn^{2+}$, $Fe^{3+}$, $Co^{2+}$, $Cu^{2+}$, $Cd^{2+}$, $Zn^{2+}$, $Pb^{2+}$, and $Ni^{2+}$ was studied using flame atomic absorption spectrometry (FAAS) for metal monitoring in environmental samples. $Cd^{2+}$, $Zn^{2+}$, $Pb^{2+}$, and $Ni^{2+}$ ions were quantitatively recovered at the rate of96. 0%, 101.0%, 101.0%, and 95.0%, respectively (RSD < 5%), from the studied solutions. The procedure is based on the retention of analytes on a short column of 1, 2-bis (o-aminophenylthio) ethane-XAD-4 chelating resin from a buffered sample solution and subsequent elution with 1 M $HNO_3$. Various parameters, such as pH, eluent type, and concentration, flow rate of sample solution and matrix interference effect on the retention of the metal ions have been studied. The optimum pH for the sorption of the above-mentioned metal ions was about 6. The adsorption and batch capacity of adsorbent and loading half time $(t_{1/2})$ for $Ni^{2+}$, $Zn^{2+}$, $Cd^{2+}$, and $Pb^{2+}$ were established. The limit of detection was 3.0 $mu g$ $L^{-1}$ for $Pb^{2+}$ and $Ni^{2+}$, 0.6 $mu g$ $L^{-1}$ for $Cd^{2+}$, and 0.3 $mu g$ $L^{-1}$ for Zn2+. The validation oft he procedure was carried out by analysis of certified reference materials and standard addition. The proposed enrichment method was applied to environmental samples from Trabzon.