• shareshare
  • link
  • cite
  • add
Powered by OpenAIRE graph
Found an issue? Give us feedback
Other research product . 2017

A Lab-On-Chip Phosphate Analyzer for Long-term In Situ Monitoring at Fixed Observatories: Optimization and Performance Evaluation in Estuarine and Oligotrophic Coastal Waters,

Grand, Maxime M.; Clinton-Bailey, Geraldine S.; Beaton, Alexander D.; Schaap, Allison M.; Johengen, Thomas H.; Tamburri, Mario N.; Connelly, Douglas P.; +2 Authors
Open Access
Published: 01 Jan 2017

The development of phosphate sensors suitable for long-term in situ deployments in natural waters, is essential to improve our understanding of the distribution, fluxes, and biogeochemical role of this key nutrient in a changing ocean. Here, we describe the optimization of the molybdenum blue method for in situ work using a lab-on-chip (LOC) analyzer and evaluate its performance in the laboratory and at two contrasting field sites. The in situ performance of the LOC sensor is evaluated using hourly time-series data from a 56-day trial in Southampton Water (UK), as well as a month-long deployment in the subtropical oligotrophic waters of Kaneohe Bay (Hawaii, USA). In Kaneohe Bay, where phosphate concentrations were characteristic of the dry season (0.13 ± 0.03 μM, n = 704), the in situ sensor accuracy was 16 ± 12% and a potential diurnal cycle in phosphate concentrations was observed. In Southampton Water, the sensor data (1.02 ± 0.40 μM, n = 1,267) were accurate to ±0.10 μM relative to discrete reference samples. Hourly in situ monitoring revealed striking tidal and storm derived fluctuations in phosphate concentrations in Southampton Water that would not have been captured via discrete sampling. We show the impact of storms on phosphate concentrations in Southampton Water is modulated by the spring-neap tidal cycle and that the 10-fold decline in phosphate concentrations observed during the later stages of the deployment was consistent with the timing of a spring phytoplankton bloom in the English Channel. Under controlled laboratory conditions in a 250 L tank, the sensor demonstrated an accuracy and precision better than 10% irrespective of the salinity (0–30), turbidity (0–100 NTU), colored dissolved organic matter (CDOM) concentration (0–10mg/L), and temperature (5–20◦C) of the water (0.3–13 μM phosphate) being analyzed. This work demonstrates that the LOC technology is mature enough to quantify the influence of stochastic events on nutrient budgets and to elucidate the role of phosphate in regulating phytoplankton productivity and community composition in estuarine and coastal regimes. Refereed 14.A Nutrients TRL 8 Actual system completed and "mission qualified" through test and demonstration in an operational environment (ground or space) Manual (incl. handbook, guide, cookbook etc) Standard Operating Procedure


In situ phosphate analysis, Molybdenum blue, Microfluidics, Phospate sensor, Nutrient sensor challenge, :Chemical oceanography::Nutrients [Parameter Discipline], :nutrient analysers [Instrument Type Vocabulary]

39 references, page 1 of 4

ACT (2017). Performance Verification Statement for the NOC Phosphate Analyzer. ACT Code CBL 2017-049. Solomons, MD: Alliance for Coastal Technologies. Available online at:

Adornato, L. R., Kaltenbacher, E. A., Greenhow, D. R., and Byrne, R. H. (2007). High-resolution in situ analysis of nitrate and phosphate in the oligotrophic ocean. Environ. Sci. Technol. 41, 4045-4052. doi: 10.1021/es0700855 [OpenAIRE]

Barus, C., Romanytsia, I., Striebig, N., and Garçon, V. (2016). Toward an in situ phosphate sensor in seawater using Square Wave Voltammetry. Talanta 160, 417-424. doi: 10.1016/j.talanta.2016.07.057 [OpenAIRE]

Beaton, A. D., Cardwell, C. L., Thomas, R. S., Sieben, V. J., Legiret, F.-E., Waugh, E. M., et al. (2012). Lab-on-chip measurement of nitrate and nitrite for in situ analysis of natural waters. Environ. Sci. Technol. 46, 9548-9556. doi: 10.1021/es300419u

Benitez-Nelson, C. R. (2000). The biogeochemical cycling of phosphorus in marine systems. Earth Sci. Rev. 51, 109-135. doi: 10.1016/S0012-8252(00) 00018-0

Bricker, S. B., Longstaff, B., Dennison, W., Jones, A., Boicourt, K., Wicks, C., et al. (2008). Effects of nutrient enrichment in the nation's estuaries: a decade of change. Harmful Algae 8, 21-32. doi: 10.1016/j.hal.2008.08.028

Clinton-Bailey, G. S., Grand, M. M., Beaton, A. D., Nightingale, A. M., Owsianka, D. R., Slavik, G. J., et al. (2017). A lab-on-chip analyzer for in situ measurement of soluble reactive phosphate: improved phosphate blue assay and application to fluvial monitoring. Environ. Sci. Technol. doi: 10.1021/acs.est.7b01581. [Epub ahead of print].

De Carlo, E. H., Hoover, D. J., Young, C. W., Hoover, R. S., and Mackenzie, F. T. (2007). Impact of storm runoff from tropical watersheds on coastal water quality and productivity. Appl. Geochem. 22, 1777-1797. doi: 10.1016/j.apgeochem.2007.03.034

Drupp, P., De Carlo, E. H., Mackenzie, F. T., Bienfang, P., and Sabine, C. L. (2011). Nutrient inputs, phytoplankton response, and CO2 variations in a semienclosed subtropical embayment, Kaneohe Bay, Hawaii. Aquat. Geochem. 17, 473-498. doi: 10.1007/s10498-010-9115-y

Floquet, C. F., Sieben, V. J., Milani, A., Joly, E. P., Ogilvie, I. R. G., Morgan, H., et al. (2011). Nanomolar detection with high sensitivity microfluidic absorption cells manufactured in tinted PMMA for chemical analysis. Talanta 84, 235-239. doi: 10.1016/j.talanta.2010.12.026

Powered by OpenAIRE graph
Found an issue? Give us feedback
Funded by
SenseOCEAN: Marine sensors for the 21st Century
  • Funder: European Commission (EC)
  • Project Code: 614141
  • Funding stream: FP7 | SP1 | ENV
Related to Research communities
European Marine Science Marine Environmental Science : SenseOCEAN: Marine sensors for the 21st Century