Abstract: A method for the determination of trace elements in traditional Chinese medicines by graphite furnace atomic absorption spectrometry (GFAAS) is described. The matrix modifier used in this work was NH₄H₂PO₄. The effects of matrix quantity, ashing temperature and atomization temperature were investigated. Matrix modifier NH₄H₂PO₄ can not only improve the sensitivity of determination but also eliminate the matrix effect. Under the optimum experimental conditions, copper, iron and zinc in traditional Chinese medicines such as radix angelicae sinensis, flos sophorae, herba taxilli, folium apocyni veneti and radix scutellarae were determined. The recoveries are between 90% and 110%, the relative standard deviation is less than 5%, and the experimental results are satisfactory. This method is rapid and reliable. It provides a simple method for the determination of trace elements in traditional Chinese medicines.

Key words: graphite furnace atomic absorption spectrometry, traditional Chinese medicine,  trace element, matrix modifier