Investigation on four heavy metal constituents of commercial restorative Chinese medicines

Abstract

This study undertook the analysis of Cd, Cr, Mn, and Pb constituents in the various forms of five restorative preparations from ten GMP Chinese medicine laboratories. Collected samples of the commercial drugs were digested with HNO3-HClO4 in the presence of microwaving, followed by atomic absorption spectrophotometric analysis the results showed higher levels in the Mn content (27.9 ± 19.8 ppm) than Cr (2.86 ± 2.04 ppm), Pb (0.247 ± 0.578 ppm), and Cd (0.157 ± 0.167 ppm), based on the dry weight of the samples. The variation of heavy metal contents between laboratories, prescriptions, prescribed doses, and lot numbers may be attributed to the differences in the origin of raw materials as well as the additives used in the processing procedure. Comparison between prescriptions exhibited higher heavy metal contents (53.6 ± 24.7 ppm, the sum of Cd, Cr, Mn and Pb) in Kim-So-Ku-Gien-Wan. For purposes of safety and quality in Chinese drugs,it is necessary to confine individual heavy metal content on the basis of potential toxicity.