DETERMINATION OF LEAD AND CADMIUM IN ENVIRONMENTAL-SAMPLES OPTIMIZED BY SIMPLEX OPTIMIZED ATOMIC-ABSORPTION METHODS

Simplex optimized methods for the determination of cadmium and lead in environmental samples by use of electrothermal atomic absorption spec troscopy (ETAAS) are presented. The optimum experimental conditions we re attained by applying the composite modified simplex optimization me thod after considering the following variables: ramp to ashing tempera ture, ashing temperature, atomization ramping time, atomization temper ature and modifier concentration, The way of introducing the matrix mo difier in the graphite furnace is one of the most important among the numerous factors that must be considered for the development of an ETA AS method, The matrix modifier was injected into a graphite tube provi ded with a L'vov platform prior to the injection of the sample, leavin g the modifier wet, The analytical investigations showed that the opti mized systems are ideally suited to the analysis of cadmium and lead i n samples of environmental origin offering good accuracy and precision .