用微波消解法进行样品消解,原子吸收光谱法测定了小麦粉国家标准物质中铅、铜、镉、镁、锰、铁6种元素的含量.其中镁、锰、铁用火焰原子化法,铅、铜、镉用石墨炉原子化法,方法的相对标准偏差分别为1.43%(镁),4.72%(镉),5.20%(锰),6.04%(铜),13.8%(铁)及18.7%(铅),检出限分别为0.001(铅及铜),0.000 1(镉),0.01(锰)及0.02(镁和铁) mg·kg-1.

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).