The internal standard method was established to determine the trace elements, such as Li, Sr, Sb, Pb, V, Mn, Fe, Cu and Zn, in Qiangyong snow ice samples by high resolution inductively coupled plasma mass spectrometry (ICP-MS) in the ultraclean laboratory. Indium (In115) was used as the internal standard element in the method. The detection limit, determine precision and the expanded uncertainty of the method are given. The method accuracy is controlled through determining the international River Water Reference Material for Trace Metals (SLRS-5). Lead in SLRS-5 and ice samples was used to describe the uncertainty source of reference standard water and the ice samples. The analysis shows that the uncertainty sources are made up of three parts for reference standard water, including uncertainty caused by the preparation process of standard solution, calibration curve and repeatability. The real snow samples have nonuniformity. So the uncertainty sources include four parts, which are the preparation process of standard solution, calibration curve, repeatability and the nonuniformity of sample. For a real snow sample, the expanded uncertainty is mainly from the uncertainty caused by nonuniformity of sample and calibration curve. The uncertainty from preparation process of standard solution and repeatability is not so distinct.

Download