Determination of lead in cookies by electrothermal atomic absorption spectrometry with various chemical modifiers

The determination of lead in some Turkish cookies has been studied in the presence of some chemical modifiers. In order to decrease the interferences of sample matrix and to stabilize the atomic absorption signal of lead, W, Pd, W+Pd and W+Pd+tartaric acid (TA) have been tested as matrix modifier. Modifiers have been compared in terms of pyrolysis temperature, atomization and background profiles, precision and accuracy. The W+Pd+TA modifier mixture was found to be preferable for the determination of lead in cookies. The recovery and limit of detection of lead were about 99% and 1.2 μg/l, respectively.