Marine Science Faculty Publications

Determination of Nanomolar Levels of Nutrients in Seawater

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Determination, Flow analysis, Liquid-core waveguide, Liquid waveguide capillary cell, Measurement protocol, Nanomolar concentration, Nutrient, Seawater, Solid-phase extraction, Trace nutrient

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Nutrients (phosphate, nitrate, nitrite, ammonium and silicate) exert strong controls on oceanic primary productivity. In oligotrophic areas, which cover approximately 40% of the world's oceans, nutrient concentrations can drop to nanomolar levels or lower due to biological uptake, so highly sensitive methods and technologies are urgently needed for nutrient measurements in such areas. In this work, we review procedures for phosphate and nitrite/nitrate analyses published since the review of Patey et al. [32], and procedures for analysis of ammonium and silicate at nanomolar levels. Our review includes aspects of measurement protocols that bear strongly on the quality of analyses of trace nutrients, including contamination of reagents, sample storage, and preparation of nutrient-free seawater. This review excludes methods that have limits of detection greater than 1 µM, and methods that are not specific to seawater.

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Citation / Publisher Attribution

TrAC Trends in Analytical Chemistry, v. 60, p. 1-15