Determination of Rare Earth Elements in Human Lung and Kidney at Ultratrace Levels by Microwave Dissolution and Inductively Coupled Plasma-MS Spectrometry

Objective To establish the method for the determination of rare earth elements at ultratrace levels in human organs.Methods The samples were digested by closed-vessel microwave HNO₃+H₂O₂ dissolution system.The solution was directly analyzed by ICP-MS for the determination of La、Ce、Pr、Nd、Sm、Eu、Gd、Tb、Dy、Ho、Er、Tm、Yb、Lu in human lung and kidney with rhenium internal calibration.Results The method provided excellent sensitivity and accuracy.It was efficiency for the determinatin of fourteen REEs.The detection limits were range from 0.8ng/L to 4ng/L depending on the elements.Linear calibration plots exhibited over three orders of magnitude with standard linear correlation r≥0.997.Recoveries of spiked samples were of the range 98%-113% and precision was fine RSD>3%.The results showed close agreement with the reference values in two standard reference materials of human hair GBW07601 and wheat flour GBW08503.Conclusion ICP-MS was an effective method to analyse rare earth elements of lung and kidney.Using Rh as an internal standard compensated the depression of signal.The problem of the molecular overlaps was corrected by the interference correction factor.