ICP-MS Determination of Harmful Elements in Morinda Officinalis How with Pressurized Sample Digestion

Sample of Morinda officinalis how was digested under pressure in a tightly capped vessel with a mixture of HNO3 and H2O2,and contents of harmful elements (Cu,Zn,As,Cd and Pb) in the sample solution were determined by ICP-MS.Under the optimized conditions,values of detection limit (3s/k) found for the elements mentioned above were in the range of 0.02-0.12 μg·L-1.The proposed method was used in the analysis of substantial sample of the traditional Chinese herb,and test for recovery was made by standard addition method using the sample as matrix.Value of RSD′s (n=5) and recovery found for these 5 elements were in the range of 1.7%-5.5% and 96.1%-103.7% respectively.