Determination of heavy metals for the quality control in argentinian herbal medicines by ETAAS and ICP-OES

The determination of trace elements in Hypericum perforatum leaves and flowers, their teas, tinctures and tablets was carried out by Electrothermal Atomic Absorption Spectrometry (ETAAS) and Ultrasonic Nebulization System coupled to Inductively Coupled Plasma Optical Emission Spectrometry (USN-ICP-OES). Hypericum perforatum (St. John's wort), is a phytomedicine used for the treatment of depression. Samples were collected from different sources in the argentinian market. Heavy metals contents in the investigated samples were found at different levels. Chromium and cobalt were undetectable above their limits of detection in both liquid and solid samples; while aluminum, cadmium, lead, iron and vanadium were present in the majority of samples. The analytical results obtained for all metals indicate that they were present at concentration well below the acceptable daily intake recommended by the World Health Organization. Based on the results obtained in the present work, it is concluded that the present techniques are suitable for the routine determination of heavy metals concentration in phytopharmaceuticals. (C) 2007 Elsevier Ltd. All rights reserved.