|Title||Assessment of cleaning methods for electro-welded sieves to reduce/eliminate carry over contamination between till samples|
|Author||Grenier, A; Connell-Madore, S; McClenaghan, M B; Wygergangs, M; Moore, C S|
|Source||Geological Survey of Canada, Open File 7769, 2015, 24 pages, https://doi.org/10.4095/296314|
|Publisher||Natural Resources Canada|
|File format||pdf; xls|
|Subjects||miscellaneous; equipment standards; equipment testing; analytical methods; sample preparation; contamination|
|Illustrations||tables; photographs; flow charts; location maps; histograms|
Natural Resources Canada Library - Ottawa (Earth Sciences)
|Program||Hudson/Ungava, Northeastern Quebec-Labrador, surficial geology, GEM2: Geo-mapping for Energy and Minerals|
|Released||2015 06 18|
|Abstract||The Sedimentology Lab, with the support of the Geo-mapping for Energy and Minerals (GEM) and Targeted Geoscience Initiative (TGI4) Programs, set out to verify existing sieve cleaning methods used in
geological sample preparation laboratories to ensure no cross contamination between samples. Three cleaning methods were tested using till samples with varying degrees of mineralization. |
The purpose of this study is to determine the effectiveness
of commonly used cleaning methods at preventing cross contamination while sieving. This is critical to the quality of the geochemical analysis. Cleaning Method 1, while the quickest, does not remove contamination effectively for the two deposits
sampled for this study. The addition of an extra step in Method 2 lowered the level of the potential contaminants without significant time increase. If known high mineralization exists, cleaning Method 3 is recommended otherwise Method 2 should be
In addition to sample preparation it would be a good practice, when submitting samples to be processed for geochemical analysis, to provide a processing order to the laboratory if they are aware of any potentially metal-rich samples.
Metal-rich samples should be positioned at the end of the list to avoid any possible contamination due to sample preparation or analytical memory effect. Clean silica blanks should be inserted at the start of the batch and sieved blanks should be
inserted to verify possible contamination in the preparation lab. The insertion of control reference materials (CRMs) and duplicates are also recommended for quality control.
|Summary||(Plain Language Summary, not published)|
Data is presented on the effects of different cleaning methods applied to sieves during the preparation process for till geochemistry samples. The
results show the potential for minor cross-contamination when processing metal rich till samples prior to background till samples.