The Application Research Of Microwave Digestion ICP-AES Method Detecting Heavy Metal In Chinese Traditional Medicines

The problem of superscale heavy metals in Chinese traditional medicines is widely Concerned in recent years. However, no canonical and sensitive methods to determine heavy metals in Chinese traditional medicines are upbuild yet interiorly. Through all-round saw about the factors including sampling, raw sample pretreatment, graphite furnace working conditions, sample determination and the so on, a sensitive, reliable, method for the determination of heavy metals in Chinese traditional medicines was established. The thesis contains five main parts:Assurance the sampling method of Shanyao, Gancao sample. Through the examination of heavy metals content in the batch of same race sample, verified the sample even of Shanyao, Gancao. Chose the reasonable sampling method finally. This method have better representative, and can reflect the true circumstance of the whole sample.The pretreatment of raw samples by microwave digestion was investigated. Factors such as grain size, inceptive power, digesting temperature, digesting time Were investigated one by one. Each item has some effect on sample digestion, while Inceptive power and digesting temperature effect it most. The best digestion condition was then selected: grain size 80, inceptive power 400 W, maximum digesting temperature 200℃, digesting time 28 minutes. It can make the digesting course complete.Investigated the best working condition of ICP-AES when it determine Cr, Pb, Cd. Including emission power, carry gas stream amount, assistant gas stream amount, Cooling gas amount, observation height, wavelength, read time, rinse time, etc. And assured the best work condition of the instrument.Using the method set-up in front, 60 batches of sample were determined and the conclusion was made. Based on the results, some suggestions on the improving of medicine manufacturing and the prospect of further researching were carried out.Combined with the methodology guideline including line relation, detection limit, precision, accuracy, the method set-up was verified. The regression equation of Cr, Pb, Cd were y=33942.1x+1.12(r=0.999); y=3493.7x+34.2 (r=0.996); y=45252.2x+18.6(r=0.999), respectively. Detection limits were 0.10μg/M1, 0.05μg/mL, 0.06μg/mL, respectively. Experiments of repeatability and recovery showed favorable precision and accuracy.