Rapid determination of lead extracted by acetic acid from glazed ceramic surfaces by flow injection on-line preconcentration and spectrophotometric detection

摘要

A. rapid method has been developed for the determination of lead extracted by acetic acid from glazed ceramic surfaces by flow injection analysis without any pretreatment. An aliquot of 4% acetic acid solution, which has been kept in a teacup for 24 h in the dark, is injected into a carrier solution (1 M nitric acid) and passed through a Pb-Spec resin column. After washing the column with an ammonium nitrate solution, the lead adsorbed on the column is eluted with an ammonium oxalate solution and then merged with a 4-(2-pyridylazo)resorcinol (PAR) solution, followed by measurement of the absorbance of the lead-PAR complex at 530 nm. The detection limit, concentration giving a signal equal to three times the standard deviation of the blank signal, is 8 ng ml(-1). The relative standard deviation of measurements at the 0.8 mu g ml(-1) level is 0.35% (n=5). The sample throughput is 12 per hour. (c) 2005 Elsevier B.V. All rights reserved.