The measurements were performed by using graphite furnace AAS technique with single beam mode with deuterium (D2) background correction at wavelength 217 nm and 232nm for lead (Pb) and nickle (Ni) respectively. A palladium-magnesium solution was called “Matrix Modifier” is added to the sample for getting rid of the matrix in the sample and for thermal stabilization of element during the decomposition step that proceeds atomization. The standard calibration curve was diluted automatically by using Autosampler.

Se is an essential as well as a toxic element. The concentration in serum and blood have to be within a small concentration range for optimal health conditions. Other than in human body fluids, where the normal level of Se is close to 100 µg/L, the Se concentration in milk or blood of cows is about a factor of 5 lower. Babies, brought up with cow milk instead of mother milk would therefore develop a dangerous Se deficiency if the infant formula would not be substituted with Se. Analytical control of Se in milk products is therefore of importance. The lowest possible expected value of Se in milk is between 10 and 20 µg/L. This is therefore the required limit of quantification for the analytical laboratory in this type of matrix as well as in body fluids in general.

The measurements were performed by using Absorption flame AAS technique with single beam mode without background correction at wavelength 589nm. Also the other technique was used for determination element in IA group of periodic table is Emission flame AAS technique without using Hollow Cathode Lamp.