Determination of Heavy Metal Elements in Cynomorium and Leek Seeds by High Resolution Continuum Source Atomic Absorption Spectrometry with Microwave Digestion

The contents of heavy metals (Cu, Pb, Cd, Cr, As, Hg)in Chinese herbal medicines (cynomorium and leek seeds) were tested using microwave digestion-high resolution continuum source atomic absorption spectrometry (HR-CS AAS). The samples were digested by microwave digestion, and methods were developed for the determination of the contents of Cu by flame atomic absorption spectrometry, Pb, Cd and Cr by graphite furnace atomic absorption spectrometry, As and Hg by hydride generation atomic absorption spectrometry, respectively. The recoveries were 95.61%~100.1%, the relative standard deviations (RSDs) were 0.8%~3.3%, and the correlation coefficients of R² were 0.999. The results showed that the contents of the above-mentioned heavy metal elements in cynomorium and leek seeds were all lower than the permitted values in the standard of "medicinal plants and preparation of green import industry standard" and National food safety standard "limited quantity of pollutants in food". The established method are simple, rapid, accurate and reliable, and are successfully applied to analyze the contents of heavy metal elements in Chinese herbal medicines.