[Correlation studies of contents of copper and organic components in Astragalus roots]

To study the relationship between copper and organic components, total flavonoids of Astragalus (TFA), total saponins of Astragalus (TSA) and total polysaccharide of Astragalus (TPA).

TFA, TSA and TPA were extracted from Astragalus roots using different organic solvents, and determined by colorimetry. The concentration of copper in extracts was determined by graphite furnace atomic absorption spectrometry (GFAAS).

Copper was found in TFA, TPA and TSA, and its concentration in TFA and TPA was higher; the content of copper was correlated significantly to that of TFA and TPA (r1(2) = 0.754 8, F1 = 57.202, P < 0.01 and r2(2) = 0.499, F2 = 21.906, P < 0.01), while not to that of TSA ( r3(2) = 0.0026, F3 = 0.041, P > 0.1).

Correlation analysis could reveal the relationship of copper with organic components in Astragalus roots; contents and structure characteristics of organic components might be important factors influencing the distribution of copper in Astragalus roots.