Atomic Absorption Spectrometric Determination of Lead,Copper,Cadmium,Magnesium,Manganese and Iron in Grains with Microwave Heated Sample Digestion

Contents of lead,copper,cadmium,magnesium,manganese and iron in wheat powder were determined by atomic absorption spectrometry.Sample of wheat powder was digested with HNO3 in a tightly closed vessel heated with micro-wave.The sample solution obtained were submitted for AAS determination of the 6 elements,among which flame-atomization was used for Mg,Mn and Fe,while graphite furnace-atomization was used for Pb,Cu and Cd.Working conditions of instrument and other AAS analytical conditions were tested and described in detail.Detection limits were found as (mg·kg-1) 0.001 (for Pb and Cu),0.000 1 (for Cd),0.01 (for Mn) and 0.02 (for Mg and Fe).Values of RSD′s (n=8) obtained were 1.43% (Mg),4.72% (Cd),5.20% (Mn),6.04% (Cu),13.8% (Fe) and 18.7% (Pb).