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Verification of multiple phosphorus analyzers for use in surface-water applications

December 2, 2022

The U.S. Geological Survey (USGS) completed a verification study of selected commercially available phosphorus analyzers for their applicability to scientific surface-water applications. In this study, the analyzers were the Hach EZ7800 TOPHO, Hach Phosphax sc, Sea-Bird Scientific HydroCycle-PO4, and the YSI Inc. Alyza IQ PO4. Verification tests included laboratory trials comparing analyzer results to known standards with several known concentrations of dissolved organic matter and waste production estimates. Field trials were completed at the Vermilion River near Danville, Illinois (U.S. Geological Survey station 03339000), where analyzer-measured concentrations were compared against discrete samples across a wide range of environmental conditions from November 2020 to August 2021. Data coverage was closely tracked for analyzer malfunctions and operator errors that caused missing data. Laboratory and field trials indicated that each analyzer is a viable option for scientific surface-water studies depending on environmental conditions. Because of the complexity of the analyzers, a substantial time investiture was required to get maximum data coverage including considerable site infrastructure investments and well-trained technicians. Data coverage was closely related to each analyzer’s ability to handle elevated turbidity levels.

Publication Year 2022
Title Verification of multiple phosphorus analyzers for use in surface-water applications
DOI 10.3133/ofr20221100
Authors Colin S. Peake
Publication Type Report
Publication Subtype USGS Numbered Series
Series Title Open-File Report
Series Number 2022-1100
Index ID ofr20221100
Record Source USGS Publications Warehouse
USGS Organization Central Midwest Water Science Center