Abstract:

The mass ratios of six microelements (Cu,Zn,Fe,Mn,Ca and K) in Rehmannia glutinosa Libosch and Semen plantaginis were determined by flame atomic absorption spectrometry with the mixed acid of HNO₃HClO₄ (4 ∶1) as the digesting solution. The optimal working conditions of the instruments used to determine the different elements were studied. The elements in these two sample solutions did not interfere with each other under the given  experimental conditions, so the six elements can be examined in the same preparation solution. The results show that K>Ca>Zn>Fe>Cu>Mn in Rehmannia glutinosa Libosch and K>Zn>Ca>Fe>Cu>Mn in Semen plantaginis. The accuracy and precision of the method were examined. RSD<2.40%（n=7）, the recovery is 91.31%～106.87% for these elements.

Key words: flame atomic absorption spectrometry, Rehmannia glutinosa Libosch, Semen plantaginis; microelement