dc.contributor.author | Huang, Jianyin | |
dc.contributor.author | Bennett, William W | |
dc.contributor.author | Teasdale, Peter R | |
dc.contributor.author | Kankanamge, Nadeeka Rathnayake | |
dc.contributor.author | Welsh, David T | |
dc.date.accessioned | 2017-12-11T00:54:18Z | |
dc.date.available | 2017-12-11T00:54:18Z | |
dc.date.issued | 2017 | |
dc.identifier.issn | 0003-2670 | |
dc.identifier.doi | 10.1016/j.aca.2017.08.024 | |
dc.identifier.uri | http://hdl.handle.net/10072/355168 | |
dc.description.abstract | A modified diffusive gradients in thin films (DGT) technique uses both a mixed binding layer (PrCH and A520E resins for NH4-N and NO3-N, respectively) and multiple binding layers (Metsorb binding layer for PO4-P overlying the mixed binding layer) for the simultaneous measurement of dissolved inorganic nitrogen (nitrate and ammonium) and phosphate in freshwater (INP-DGT). High uptake and elution efficiencies were determined for a mixed (PrCH/A520E) binding gel for dissolved inorganic nitrogen and an agarose-based Metsorb binding layer for PO4-P. Diffusion coefficients (D) obtained from DGT time-series experiments (conductivity 180 μS cm−1) for NH4-N, NO3-N and PO4-P agreed well with those measured using individual DGT techniques in previous studies, but were characterised over a wider range of ionic strengths here. D for NO3-N and PO4-P were constant over a range of ionic strengths (between 100 and 800 μS cm−1) while the diffusion coefficient for NH4-N decreased with increasing ionic strength, as reported previously. The measurement of NH4-N, NO3-N and PO4-P using the INP-DGT was independent of pH (3.5–8.5) and quantitative over varying ionic strength ranges (up to 0.004 mol L−1 NaCl for NH4-N, up to 0.014 mol L−1 NaCl for NO3-N and over 0.1 mol L−1 NaCl for PO4-P) for a 24 h deployment time. Performance of INP-DGT in synthetic freshwaters with differing conductivity indicated the three nutrients were affected differently, with NH4-N measurements being most sensitive. Representative performance was determined for NO3-N (90–330 μS cm−1) and PO4-P (all tested conductivities) over a 72 h deployment period and for NH4-N (<330 μS cm−1) over a 24 h deployment period. Field validations showed that the ratios of INP-DGT concentrations to the average concentrations from grab samples were generally between 0.80 and 1.13 over 24 and 48 h deployment periods. To ensure the representative performance of INP-DGT for all three nutrients, the conductivity should not exceed 400 μS cm−1 and deployment times should be no longer than 24 h. The results of this study have demonstrated that INP-DGT could provide a cost-effective monitoring technique for measuring time-weighted average concentrations of dissolved inorganic nutrients in many freshwaters. | |
dc.description.peerreviewed | Yes | |
dc.language | English | |
dc.language.iso | eng | |
dc.publisher | Elsevier Science | |
dc.relation.ispartofpagefrom | 17 | |
dc.relation.ispartofpageto | 26 | |
dc.relation.ispartofjournal | Analytica Chimica Acta | |
dc.relation.ispartofvolume | 988 | |
dc.subject.fieldofresearch | Analytical chemistry | |
dc.subject.fieldofresearch | Analytical chemistry not elsewhere classified | |
dc.subject.fieldofresearch | Other chemical sciences | |
dc.subject.fieldofresearch | Chemical engineering | |
dc.subject.fieldofresearch | Nanotechnology | |
dc.subject.fieldofresearchcode | 3401 | |
dc.subject.fieldofresearchcode | 340199 | |
dc.subject.fieldofresearchcode | 3499 | |
dc.subject.fieldofresearchcode | 4004 | |
dc.subject.fieldofresearchcode | 4018 | |
dc.title | A modified DGT technique for the simultaneous measurement of dissolved inorganic nitrogen and phosphorus in freshwaters | |
dc.type | Journal article | |
dc.type.description | C1 - Articles | |
dc.type.code | C - Journal Articles | |
gro.faculty | Griffith Sciences, Griffith School of Environment | |
gro.hasfulltext | No Full Text | |
gro.griffith.author | Bennett, Will W. | |
gro.griffith.author | Huang, Jianyin | |