Multi-element analysis of Traditional Mongolian Medicine Ga-Mu-Zhu-Er using inductively coupled plasma mass spectrometry

Due to the high level of heavy metals and harmful elements, United States and Europe are precautious in importing herbal medicines, which has seriously hindered the internationalization process of traditional Chinese and Mongolian medicines. Ga-Mu-Zhu-Er (GMZE) contains a wide range of chemical compounds and inorganic elements. This paper describes a validation process for the simultaneous analysis of 30 elements in Traditional Mongolian Medicine GMZE samples with closed-vessel microwave digestion technique followed by inductively coupled plasma-mass spectrometry (ICP-MS) analysis. The samples digested with concentrated nitric acid (65%, v/v) revealed recoveries ranging from 91.9 to 107.7%. Several other parameters, including linearity, specificity, the limit of detection (LOD) and quantification (LOQ), precision of measurement, repeatability, intermediate precision and accuracy, were validated. The LOD were found to be in the range of 0.00015-0.21 µg/L, and the LOQ were between 0.00046 to 0.64 µg/L. Three GMZE samples were analyzed. Among the analyzed elements, Ca, As, and Hg were the most abundant, whereas, Be and Ag were present in low concentrations in all the samples. The results obtained in our study demonstrated that the developed ICP-MS method is simple, fast, and reliable, which could be used for the routine quantitation of these 30 essential and non-essential trace elements in GMZE as well as other Traditional Chinese Medicines and dietary supplements, with acceptable analytical performance.