Determination of rare earth elements in human hair and wheat flour reference materials by inductively coupled plasma mass spectrometry with dry ashing and microwave digestion

A method was developed for the determination of ail rare earth elements (REEs) at sub ng g(-1) levels in human hair (GBW 09101, SRM, Republic of China) and wheat flour (GBW 08503, SRM, Republic of China) by Inductively coupled plasma mass spectrometry (ICP-MS). The values obtained by dry ashing and microwave oven digestion procedures were compared with those obtained by traditional open vessel acid digestion method. The validity of the analytical procedure was examined by analyzing spiked samples and two vegetables (GBW 07603 and GBW 07605, SRMs, Republic of China). The results are satisfactory. The detection limits for 14 REEs ranged from 0.0039 to 0.0003 ng cm(-3) in solution and the quantification limits ranged from 0.16 to 0.01 ng g(-1) in solid sample. The precision for most REEs were less than 10% RSD. (C) 1998 Elsevier Science B.V. All rights reserved.