Lead Determination in Chinese Herbal Medicine by Graphite Furnace Atomic Absorption Spectrometry Using Matrix Modifier

An effective and expeditious method was developed for continuous determination of Pb in Chinese herbal medicine of Panax Notoginseng by using graphite furnace atomic absorption spectrometry (GFAAS) with high-pressure digestion. Under the optimum conditions, the linear range of Pb was 0 to 50 mu g/L, and its detection limits was 0.871 mu g/L, with 2% (NH4)(2)HPO4 was used as matrix modifier, respectively. The precision relative standard deviations was 3.98% for determining Pb by this method, and the spike recoveries range from 93.4% to 103.0%.