Trace element contamination of sand samples by grinding

Olivier Pourret 

Blanks during powdering processes were examined for major and trace elements using inductively coupled plasma mass spectrometry (ICP-MS). Quartz sand (reference CV32.2) was used as a test substrate for powdering with grinding mills of several kinds: an agate mortar grinder, a stainless steel mortar grinder, a hard porcelain mortar grinder, an agate hand mill, and a hard porcelain
hand mill. The stainless steel mortar grinder introduced significant contamination in Fe2O3, Mo, Cu, and Ni. The agate mortar grinder introduced minor W contamination. The hard porcelain mortar grinder introduced minor Cs contamination. The agate hand mill and hard porcelain hand mill showed minimal contamination for most elements examined. These results emphasize the importance of careful selection of grinding mills for sample pulverization prior to ICP-MS trace element analysis.