Estimation Of Copper, Zinc And Lead In Choornas By Flame Atomic Absorption Spectroscopy

Choornam is one of the most common dosage form used in Ayurveda and Siddha system of Medicine. A common misperception is that medicaments of natural substances may not cause toxicity. However, the safety of natural substances has been questioned recently due to the presence of heavy metals above the permissible range. In this study, an attempt was made to estimate the concentration of Cu, Zn and Pb in Choornas. Samples of four different types of Choornas were prepared as per IM-COPS standard procedure and digested by a Microwave-assisted method in closed vessels. The solvent used to digest the samples were HNO3 and H2O2 in the ratio of 4:6 with an irradiation power of 900W and time of 2.5 min. The digested samples were analyzed by Flame Atomic Absorption Spectroscopy. The linearity was plotted for each standard in concentration range of Cu (0.5-2.5 µg/ml), Pb (1.0-5.0 µg/ml) and Zn (5.0-25.0 µg/ml). The concentration of Cu, Zn and Pb in the four formulated Choornas were in the range of Cu (7.0-42.0 μg/gm), Zn (393-1604.4 µg/gm) and Pb (35.7 - 41.8 μg/gm). Thus the analysis of laboratory prepared authentic formulations revealed the presence of lead beyond the limits specified by WHO and FDA [10 ppm]. Copper and Zinc were found within the permissible limits. The contamination may be due to improper selection, identification, collection and variation in processing conditions.