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TitleAssessment of cleaning methods for electro-welded sieves to reduce/eliminate carry over contamination between till samples
AuthorGrenier, A; Connell-Madore, S; McClenaghan, M B; Wygergangs, M; Moore, C S
SourceGeological Survey of Canada, Open File 7769, 2015, 24 pages, (Open Access)
PublisherNatural Resources Canada
Documentopen file
Mediaon-line; digital
File formatreadme
File formatpdf; xls
Subjectsmiscellaneous; equipment standards; equipment testing; analytical methods; sample preparation; contamination
Illustrationstables; photographs; flow charts; location maps; histograms
Natural Resources Canada Library - Ottawa (Earth Sciences)
ProgramHudson/Ungava, Northeastern Quebec-Labrador, surficial geology, GEM2: Geo-mapping for Energy and Minerals
Released2015 06 18
AbstractThe 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 sufficient.
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.