Comparison of dry Ashing, wet Ashing and microwave digestion for determination of trace elements in Periostracum Serpentis and Periostracum cicadae by ICP-AES

Abstract

The work was to demonstrate a repaid, precise and accurate determination method for ten trace elements (Al, Cd, Cr, Cu, Fe, Mg, Mn, Ni, Se and Zn) in periostracum serpentis (PS) and periostracum cicadae (PC) by inductively coupled plasma atomic emission spectrometry (ICP-AES). In order to evaluate the best digestion method, three different sample digestion methods including dry ashing, wet ashing and microwave digestion procedures were compared in this study. Method validation was carried out through the generation of calibration curves with multi-element standard solutions and a standard addition method by using standard reference material (GBW 07604-Poplar leaves). The results revealed the microwave digestion procedures were the best sample digestion method because of dry ashing and wet ashing procedures without any advantages in terms of digestion efficiency than the microwave digestion procedures. Trace element contents in PS and PC samples presented a wide variability from the test results, and ten trace element contents in PC were found to be higher than in PS. Determination of trace elements by ICP-AES after microwave digestion was more sensitive and precise, which can be used for quality control and analysis of pharmacological effect in various ecdyses of some animal samples.