Abstract: Objective To develop a method of hydrogen peroxide microwave digestion and sequential injection cold-atomic fluorescence spectrometry for the determination of Hg content in 8 medicinal and edible Chinese medicinal herbs including dendrobium officinale. Methods The Chinese medicinal materials samples were digested by microwave digester using nitric acid-hydrogen peroxide system,and the digestion system,microwave program,mercury lamp preheating,carrier gas and shielding gas flow,carrier current and potassium borohydride concentration were studied. Results Under the conditions proposed,the linear range was 0-1.0 μg/L,the linear regression equation was Y=1 586.13X-21.93,the correlation coefficient（r） was 0.999 8,the detection limit of Hg was 0.011 μg/L,the relative deviation was 1.34% and the recovery was 92.4%-102.4%. Conclusion The method is simple,and has good accuracy and hight sensitivity. It can be easily used for the determination of Hg in Chinese medicinal materials.

Key words: Microwave digestion, Hydrogen peroxide, Cold-atomic fuorescence spectrometry, Hg, Medicinal and edible Chinese medicinal herbs