Verplanck and 3 co-authors, reported in 2001 that standard reference water samples (SRWS) were collected from two mine sites, one near Ophir, CO, USA and the other near Redding, CA, USA. The samples were filtered, preserved, and analyzed for rare earth element (REE) concentrations (La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu) by inductively coupled plasma-mass spectrometry (ICP-MS). These two samples were acid mine waters with elevated concentrations of REEs (0.45± 161 mg/l).
Seventeen international laboratories participated in a `round-robin' chemical analysis program, which made it possible to evaluate the data by robust statistical procedures that are insensitive to outliers. The resulting most probable values are reported. Ten to 15 of the participants also reported values for Ba, Y, and Sc. Field parameters, major ion, and other trace element concentrations, not subject to statistical evaluation, are provided.
This study has evaluated the REE determinations of 2 reference water samples in the first inter-laboratory comparison for REEs in waters. The 17 participating laboratories used the ICP-MS technique to determine the elemental concentrations. The MPVs were determined using robust statistical procedures that are insensitive to outliers. Uncertainty in the MPVs range from 2 to 9%. The shale-normalized REE patterns of both waters display a smooth, convex upward pattern with the SCREE1 pattern having a slight negative Eu anomaly. Although little change in the REE concentrations of these SRWS was expected, periodic analyses of the reference waters will be conducted to determine the long-term stability of their constituents. After 1 year no change in concentration has been observed. These new SRWS are available from the authors upon request.
Managed & Built by I2M Consulting, LLC | © 2010-
