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

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 24h in the dark, is injected into a carrier solution (1M 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 530nm. The detection limit, concentration giving a signal equal to three times the standard deviation of the blank signal, is 8ngml(-1). The relative standard deviation of measurements at the 0.8mugml(-1) level is 0.35% (n=5). The sample throughput is 12 per hour.