Preconcentration of trace cadmiun from water samples using 4-(2-Pyridylazo)-resorcinol/Capriquat loaded silica gel.

Abstract

The separation and preconcentration of trace Cd from water samples for a graphite-furnace AAS determination was studied using silica gel loaded with 4-(2-Pyridylazo)-resorcinol (PAR)/Capriquat. A sample solution of 100700 ml containing Cd was adjusted to pH 11. The solution was then passed through a column packed with 300 mg of PAR/Capriquat-loaded silica gel at a flow rate of 10 ml min-1. The Cd collected on the PAR/Capriquat-loaded silica gel column was eluted with 5 ml of 0.5 M nitric acid, and then determined by GF-AAS. In this method, over 99% of the Cd was preconcentrated at about pH 11. The calibration curve was linear over the range 0.02 to 2.5μg/l of cadmium. The proposed method has been applied to the determination of Cd in seawater samples.