Data from the development and testing of a multiparameter standard solution for fluorescent dissolved organic matter (fDOM) and algal fluorescence (fChl) (ver. 2.0, July 2022)

Optical sensors measuring fluorescence of non-biological sources (e.g., dissolved organic matter, wastewater, hydrocarbons, fluorescent dyes, etc.; hereafter referred to as fDOM) are increasingly used in water quality studies because they provide proxy measurements for a variety of contaminants and constituents of concern including metals, wastewater effluent, and DOM (measured in the lab as dissolved organic carbon, (DOC)) concentrations. Similarly, sensors measuring biological (algal) fluorescence (hereafter referred to as chlorophyll (fChl) and phycocyanin (fPC), have gained popularity to measure phytoplankton concentration, biomass, and even primary productivity. As additional sensors are coupled with ongoing field monitoring, field calibration checks are becoming quite time consuming for even the basic set of sensors (i.e., pH, specific conductivity, turbidity) that require ongoing verification over timescales ranging from weekly to semi-annual intervals. As such, there is a critical need to establish a means to verify calibrations using a simple, fast, and efficient method in the field, allowing for the standardization of United States Geological Survey (USGS) measurements across the entire agency. Here, we present the results of testing a multiparameter field standard (MPFS), an experimental mixed standard solution capable of simultaneously verifying calibrations for multiple fluorescence sensors (fDOM, fChl, and fPC).