Analysis of metallic elements in"Zogta"with microwave digestion and inductively coupled plasma mass spectrometry(ICP-MS)

Objective:To establish an ICP-MS method for the determination of metallic elements,including Hg, Ca,K,Fe,Cu,Zn and Pb in Tibetan medicineZogta.Method:The sample was digested with microwave digestion system,and the contents of 7 metallic elements were analyzed by ICP-MS.Serial mixed standard solutions were prepared by 5% HNO_3.The concentrations of Hg was 0,20,50,100,200,500 μg·L~(-1);Ca,Pb were 0,5,10,20, 50,100 μg·L~(-1);K,Fe were 0,10,20,50,100,200 μg·L~(-1);and Cu,Zn were0,1,2,5,10,20 μg·L~(-1),respec- tively.~(209)Bi、~(45)Sc and ~(72)Ge were selected as on-line internal standard elements and the instrument parameters were adjusted to good state.The accuracy and precision of the method were validated by measuring the relative standard deviations (RSDs) and recoveries of the measured metallic elements.Results:The linear correlative coefficients for 7 metallic elements was higher than 0.999,with the RSDs5.0% (n=6),and the average recoveries ranged from 94.7% to 103.4%.Conclusion:This method is convenient,rapid,accurate and highly sensitive.Meanwhile,the contents of the Hg,Ca,K and Fe,are significantly different in two kinds ofZogta,so syndicated quality standard system should be studied and established that safety and efficacy of the different products ofZogtacan be en- sured.