The correlation of metal content in medicinal plants and their water extracts.

The quality of some medicinal plants and their water extracts from southeast Serbia was determined on the basis of metal content using atomic absorption spectrometry. Two methods were used for the preparation of water extracts in order to examine the impact of the preparation on the content of metals in the samples. The contents of investigated metals in both water extracts were markedly lower than in medicinal plants, but were higher in the water extract prepared by method (I), with the exception of lead. The coefficients of extraction for the observed metal can be represented in the following order: Zn > Mn > Pb > Cu > Fe. Correlation coefficients between the metal concentration in the extract and total metal content in plant material varied in the range from 0.6369 to 0.9956. This indicates the need for plants to be collected and grown in unpolluted areas, and to examine the metal content. The content of heavy metals in the investigated medicinal plants and their water extracts is below the maximum allowable values, so they are safe to use. [ABSTRACT FROM AUTHOR]