The mineral content of cookies was determined by atomic absorption spectrophotometry after digestion of ground samples by HNO3 and HClO4.
A detailed description of the sample preparation, determination of elements, used reagents and analytical quality control data was reported by Škrbic´ and Cˇ upic´ (2005).
The whole procedure applied in this work was validated with certified reference material (IAEA-V-8-Rye flour) analysed in the same manner as the samples.
The recovery values, ranging from 70% to 110%, were in agreement with the certified values, confirming the accuracy of the procedure applied.