Description: Data was compiled and evaluated for the XRF Demonstration of Methods Applicability (DMA) Study, an evaluation of several vendors of X-ray Fluorescence to compare product effectiveness and develop new sampling and analysis SOPs (including employing seiving) to improve the detection limit for mercury in particular. Evaluate the performance of X-ray fluorescence (XRF) instrumentation for the simultaneous analysis of mercury (Hg), lead (Pb), arsenic (As) and selenium (Se) in soil affected by the mining operations associated with the Comstock Lode. Relevant aspects of performance include evaluation of several models of XRF for their respective detection limits, linear range, inter-element interferences, analytical precision, and comparability with other analytical methods.
Field sample collection techniques will not be evaluated as part of this study, however sample processing will be. The most effective processing and analytical techniques will be selected for use in a follow-up study which will evaluate field sample collection. It is anticipated that the most effective and efficient sampling and analysis techniques will be incorporated into future investigations for the Carson River area.
General Comments: The location coordinates represent the center point of the Decision Unit (DU) as calculated by GIS. For DUs that cross roads or driveways (SMCD2 and SMCSCR-South) the midpoint may plot in the middle of the road. The center point for SMCCBS was selected manually due to the unusual shape of the DU. The calculated GIS center point falls outside of the DU. DU columns provided on each tab for easy sorting and QC check. It is not a critical data point since the DU name is embedded in the Sample ID. For Source Units (SU) samples, the DU column is N/A if the SU was located outside of a DU, this column is filled out if the SU was located inside of a DU. Date represents sample collection date.
Tab-Specific Comments : XRF field results did not use unique Lab ID sample #s so left that column blank. Did not establish specific XRF reporting limits for this project. Manually added a “U” for the XRF ND samples to match the lab formats. Region 9 lab results for the XRF comparison samples: Left all the ICP metals in the database. R9 lab DMA data only reported Pb, As, Se, and Hg per the team decision. SPLP Extraction #2 results for the samples selected for leaching analysis - removed the rows that identify the extraction procedure and contained no lab data. SPLP Extraction #3 results for the samples selected for leaching analysis - removed the rows that identify the extraction procedure and contained no lab data. Notes column indicates this is DI water extraction.