Review of fluorescent standards for calibration of in situ fluorometers: Recommendations applied in coastal and ocean observing programs
journal contribution
posted on 2023-05-17, 12:06authored byEarp, A, Hanson, CE, Ralph, PJ, Brando, VE, Allen, SS, Baird, M, Clementson, L, Daniel, P, Dekker, AG, Fearns, PRCS, Parslow, J, Peter StruttonPeter Strutton, Thompson, PA, Underwood, M, Weeks, S, Doblin, MA
Fluorometers are widely used in ecosystem observing to monitor fluorescence signals from organic compounds, as well as to infer geophysical parameters such as chlorophyll or CDOM concentration, but measurements are susceptible to variation caused by biofouling, instrument design, sensor drift, operating environment, and calibration rigor. To collect high quality data, such sensors need frequent checking and regular calibration. In this study, a wide variety of both liquid and solid fluorescent materials were trialed to assess their suitability as reference standards for performance assessment of in situ fluorometers. Criteria used to evaluate the standards included the spectral excitation/emission responses of the materials relative to fluorescence sensors and to targeted ocean properties, the linearity of the fluorometer’s optical response with increasing concentration, stability and consistency, availability and ease of use, as well as cost. Findings are summarized as a series of recommended reference standards for sensors deployed on stationary and mobile platforms, to suit a variety of in situ coastal to ocean sensor configurations. Repeated determinations of chlorophyll scale factor using the recommended liquid standard, Fluorescein, achieved an accuracy of 2.5%. Repeated measurements with the recommended solid standard, Plexiglas Satinice® plum 4H01 DC (polymethylmethacrylate), over an 18 day period varied from the mean value by 1.0% for chlorophyll sensors and 3.3% for CDOM sensors.
History
Publication title
Optics Express
Volume
19
Issue
27
Pagination
26768-26782
ISSN
1094-4087
Department/School
Integrated Marine Observing System
Publisher
Optical Society of America
Place of publication
2010 Massachusetts Ave NW, Washington, USA, 20036
Rights statement
Copyright 2011 Optical Society of America
Repository Status
Restricted
Socio-economic Objectives
Measurement and assessment of marine water quality and condition