Comparison of digestion and solid sampling techniques for the determination of Pb and Cu in blackpepper

Copper and lead in blackpepper samples were determined by graphite furnace atomic absorption spectrometry using microwave-assisted digestion and direct solid sampling technique. At first, the samples were dissolved by microwave-assisted digestion method and directly pipetted into the graphite furnace for digestion technique. Secondly, the powdered samples were directly analysed by solid sampling technique. The experimental parameters were optimised for the two techniques. The two of the methods were applied for determination of copper and lead in pepper samples obtained commercially from markets in Istanbul, Turkey and results were statistically evaluated and compared. The limits of detections for microwave digestion and solid sampling techniques were 0.3 and 0.4ng g^-1, for lead, and 5.1 and 11.3ng g^-1, for copper, respectively. The advantages and disadvantages of the two sampling methods were discussed.