Phosphorus and nitrogen anion species are key limiting nutrients in marine and terrestrial waters integral to primary production. Phosphorus is incorporated within the ecological fauna cycle from the weathering of the apatite mineral, while nitrogen comes from microbial action. To elicit the amount of nutrients in the aquatic environment by remote sensing is a challenging goal, notably in a marine setting. To validate new technologies, a series of classic spectrocolormetric tests were used to characterize phosphorus and nitrogen speciation in these water bodies with correlation to surface bound nutrients at the sediment-water interface. A sediment depth profile of bound phosphorus and nitrogen ions to surrounding pore water was also derived, elucidating the relationship of bio available nutrients to that of permanently bound and the potential flux between the two phases. DRIFTS spectroscopy precise analytical method for the determination of the sub microgram levels of nitrate (NO3− and NO2−) in environmental samples from sediment, soil, dry deposit, and coarse and fine particles. The diffuse IR spectra of phosphate mixed powders show characteristic spectral bands of (PO43−, OH−, H2O absorbed, CO32−, HPO42−) at definite wave number ranges, which can be employed to observe the presence of phosphorus species qualitatively, quantification is somewhat more challenging. To circumvent this drawback, this research established that basic EDTA/dithionite extraction of marine sediment was superior to that of the acidic ignition technique for phosphorus. The aqueous spectrocolormetric spot tests for phosphorous and nitrogen anion determination were done following the HACH® procedure. These color spot tests were compared to instrumental analysis by HPLC-IC with inline electrochemical detection, phosphorus lines in ICP [@ 214 and 217 nm], and vacuum XRF.

Instrumental assay as a prelude to automated field anion testing

2019 Spring National Meeting

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