SOLID PHASE EXTRACTION METHOD FOR THE DETERMINATION OF TRACE METAL IONS BY ATOMIC ABSORPTION SPECTROMETRY USING AMBERLITE XAD-16 LOADED WITH BTAMB

Abstract

Application of 2-(2-benzothiazolylazo)-5-dimethyl aminobenzoic acid (BTAMB) coated Amberlite XAD-16, for preconcentration of Cu (II), Cd (II), Zn (II), Ni (II), Fe (II), Co (II) and Mn (II) by solid phase extraction and their determination by FAAS was studied. The effect of pH, type, concentration and volume of eluent, sample volume, flow rates of sample and elution solutions, and interfering ions were investigated. The optimum pH for simultaneous retention of all the metal ions was 6.5. Eluent for quantitative elution was 25 mL of 3 M HNO3. The optimum sample and eluent flow rates were found as 2 mL/min, and also sample volume was 2000 mL, except for Co (85% recovery). The sorption capacity was found between 21 and 27 mg/g and preconcentration factors ranged from 200 to 400. The recovery values for all of the metal ions were >= 95% and relative standard deviation of the determination was <= 4.8%. The detection limit values were in the range of 0.71 to 3.55 g/L. The accuracy of the method was confirmed by analysing the certified reference materials (SRM 1643e water and NCS ZC 73013 spinach) and the recovery studies. This procedure was applied successfully to the determination of Cu (II), Cd(II), Zn (II), Ni (II), Fe (II), Co (II) and Mn (II) in tap water, mineral water and food samples.