Determination of Trace Zinc in Water by Flame Atomic Absorption Spectrometry After Preconcentration by Modified Organobentonite with 1-(2-Pyridylazo)-2-naphthol

Abstract

A new solid-phase extraction method is described for the determination of traces of zinc in water samples by flame atomic absorption spectrophotometry.The method is based on sorption of zinc ion on the 1-(2-pyridylazo)-2-naphthol modified organobentonite (PAN-Obentonite).And the possible parameters influencing the enrichment and separation were optimized.In the medium of pH 6, the adsorption time was 0.5 h and capacity of adsorption was 3.8 mg/g.The zinc ion adsorbed on the sorbent could be completely eluated by using 5 mL of 1 g/L of EDTA solution.And a novel method for the determination of trace zinc in water by flame atomic absorption spectrometry after preconcentration with PAN-O-bentonite was established.The enrichment factor was more than 100.Under the optimal solid-phase extraction conditions, the method detection limit was 0.031 ug/L with preconcentrated for 100 times.The established method has been successfully applied to analyze well water and tap water sample, the RSD (n = 6) within 2.71 %.The recoveries were in the range of 93.65 to 101.7 %.Compared with other solid phase extraction agent, this method has high sensitivity, better selectivity and lower cost.