Sequential preconcentration for the ETAAS determination of Pd in human urine

A sequential injection analysis system for the determination of Pd in human urine by electrothermal atomic absorption spectrometry is described. The system runs fully independent of the autosampler of the equipment. The procedure is based on the retention of the complex formed between Pd and diethyldithiocarbamate on a column of silica C18 and elution with about 43 muL of ethanol directly into the graphite furnace. Using about 8 mL of sample resulted in a detection limit of 9 ng/L and a sampling rate of about 10 samples/h. Accuracy of the proposed methodology was evaluated by recoveries ranging between 91% and 100%. Repeatabitity assessed as %RSD in three samples with 26, 46, and 61 ng/L Pd concentration yielded 11.3, 5.8, and 4.8%, respectively.