[Application of microwave dissolution and inductively coupled plasma-MS spectrometry for determination of ultra-trace level of lanthanides in human rib].

ABSTRACT

A new method for the determination of ultra-trace level of lanthanides such as La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm Yb and Lu in human rib is explored. Closed-vessel microwave digestion with concentrated HNO3 is used for the sample preparation and the digested analyte is directly analyzed by ICP-MS. The method is sensitive and accurate and, is efficient for the determination of the fourteen lanthanides listed above. Detection limit for various elements ranges from 0.0007 microgram/L to 0.005 microgram/L. Calibration plots exhibit good linearity with high linear correlation coefficient r > or = 0.997. Recoveries of spiked samples ranges from 93.7% to 115.4%. Precision is < 3% RSD. Rhodium is used as the internal standard to compensate the signal suppression caused by the sample matrix. Isobaric overlap of polyatomic ions caused by matrix oxide/hydroxide of barium is corrected by interference correction factor. Two standard reference materials, namely "Human Hair GBW07601" and "Wheat Flour GBW08503" are used for quality control of the analyzed samples.