Determination Of Heavy Metal Elements In Maca By Microwave Digestion-double Cloud Point Extraction-MPT-AES

This paper by the method of microwave digestion,Tibet and yunnan two preprocessing,origin of card of cloud point extraction is examined in detail in the experimental conditions,and the types of chelating agent dosage,extraction solvent kinds dosage,solution p H,and other important factors influencing the optimization,through extracting the slope of standard curve of each element before and after the extraction ratio of the standard curve slope of each element that Tibet card of copper,iron,zinc,cadmium,lead,mercury enrichment ratio are:20.07,14.03,23.05,6.87,7.09,4.22;The enrichment multiples of copper,iron,zinc,cadmium,lead and mercury in yunnan maca were 21.02,15.03,22.15,8.17,7.12 and 5.22,respectively.The experimental parameters of the MPT spectrometer,such as the analytical spectral line,microwave power,carrier gas flow rate and working gas flow rate,were investigated.At the same time,the acid interference and ion interference which may affect the content of the elements to be measured were investigated and eliminated.The detection limit,precision and linear range of each element are obtained under the optimum experimental conditions.The detection limits of copper,iron,zinc,cadmium,lead and mercury were 3.0,12.4,23.6,4.48,5.3 and 4.25 ng·m L^-1,and the precision?RSD%?was 4.13,1.28,1.18,1.47,1.77 and 2.73,respectively.Linear range were 0.01?60?g·m L^-1,0.03?50?g·m L^-1,0.07?65?g·m L^-1,0.01?60?g·m L^-1,0.01?65?g·m L^-1,0.01?50?g·m L^-1.Choose microwave digestion method of traditional Chinese medicine samples card preprocessing,arranged by orthogonal test to determine the best condition of microwave digestion of the sample under test.Microwave digestion was verified by standard addition recovery test double cloud point extraction method and MPT-AES,the accuracy of the determination of trace elements in samples,the results showed that all the samples in the standard addition recovery rate of the element under test are within the scope of 93.50%?108.50%,method with high accuracy.After a series of experiments,a new method for the determination of trace elements in maca was established,which is environmentally friendly,convenient,low?cost and highly accurate.