The U.S. Geological Survey (USGS) is seeking qualified vendors to provide laboratory analytical services for lead (Pb) isotope ratio measurements on soil samples at the Geology, Geophysics, and Geochemistry Science Center in Denver, Colorado. The procurement involves conducting 420 analyses using high-resolution inductively coupled plasma mass spectrometry (HR-ICP-MS), with a focus on comparing results to thermal ionization mass spectrometry (TIMS) methods. This initiative is crucial for assessing lead contamination sources in the environment, as the isotopic ratios can help trace contamination pathways. Interested parties must submit their capability statements, including size classification and contact details, by April 9, 2025, to Lisa Williams at ldwilliams@usgs.gov. This notice serves as a market research tool and is not a solicitation for proposals.