TM22-01 Lab contamination bias leads to limits on low-conc data reporting for hexamethylenetetramine and data reloads for hexamethylenetetramine, gabapentin, guanylurea, and ractopamine, to NWIS for samples analyzed by NWQL schedule 2440

This memorandum alerts users of the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL) to a new publication that details the procedures used for determining and applying detection limits and reporting levels for results determined by NWQL methods. The citation for this journal article, shown formatted for use in USGS publications, is: Foreman, W.T., Williams, T.L., Furlong, E.T., Hemmerle, D.M., Stetson, S.J., Jha, V.K., Noriega, M.C., Decess, J.A., Reed-Parker, C., and Sandstrom, M.W., 2021, Comparison of detection limits estimated using single- and multi-concentration spike-based and blankbased procedures: Talanta, v. 228, article 122139, 15 p., accessed [enter date article accessed] at https://doi.org/10.1016/j.talanta.2021.122139.