New reactants for the colorimetric determination of ammonia

Reardon, John E.; Foreman, James A.; Searcy, Ronald L.

doi:10.1016/0009-8981(66)90120-3

Cited by 214 publications

(101 citation statements)

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“…We analyzed water samples colorimetrically for NH 4 + (salicylate method; Reardon et al 1966) on a Skalar (Breda, The Netherlands) San + Autoanalyzer and for SRP (molybdate method; Murphy and Riley 1962) on a Bran+Luebbe (Norderstedt, Germany) TRAACS 2000 Autoanalyzer II.…”

Section: Field Sampling and Laboratory Analysesmentioning

confidence: 99%

A round-trip ticket: the importance of release processes for in-stream nutrient spiraling

Schiller¹,

Bernal²,

Sabater³

et al. 2015

Freshwater Science

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Most nutrient-spiraling studies have focused on estimates of gross uptake (U gross ), which show that streams take up dissolved inorganic nutrients very efficiently. However, studies based on estimates of net uptake (U net ) emphasize that streams tend to be at biogeochemical steady state (i.e., U net ≈ 0), at least on a time scale of hours. These findings suggest that streams can be highly reactive ecosystems but remain at short-term biogeochemical steady state if U gross is counterbalanced by release (R), a process that remains widely unexplored. Here, we propose a novel approach to infer R by comparing U net and U gross estimated from ambient and plateau concentrations obtained from standard short-term nutrient additions along a reach. We used this approach to examine the temporal variation of R and its balance with U gross in 2 streams with contrasting hydrological regime (i.e., perennial vs intermittent) during 2 years. We focused on the spiraling metrics of NH 4 + and soluble reactive P (SRP), essential sources of N and P in stream ecosystems. R differed substantially between the 2 streams. The perennial stream had a higher proportion of dates with R > 0 and a 2× higher mean R than the intermittent stream for both nutrients. Despite these differences, the magnitude of R and U gross tended to be similar for both nutrients within each stream, which lead to U net ≈ 0 in most cases. A notable exception occurred for SRP in the intermittent stream, where R tended to be higher than U gross during most of the winter period, probably because of desorption of P from stream sediments. Together, our findings shed light on the contribution of release processes to the dynamics of nutrient spiraling and support the idea that streams can be active ecosystems with high spiraling fluxes while simultaneously approaching short-term biogeochemical steady-state.

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Section: Field Sampling and Laboratory Analysesmentioning

confidence: 99%

A round-trip ticket: the importance of release processes for in-stream nutrient spiraling

Schiller¹,

Bernal²,

Sabater³

et al. 2015

Freshwater Science

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“…All weight percent concentrations are presented for decarbonated samples, eliminating variability caused by high calcite or aragonite concentrations in some samples. N ex concentrations were determined spectrophotometrically using reagents for the Nitrogen, Ammonia Salicylate Method (HACH Method 8155; HACH Company, Loveland, Colorado) which was adapted from a method developed by Reardon et al [1966]. The resulting absorbances were converted to NH 4 + concentrations using a response factor (R 2 = 0.99) determined for NH 4 Cl standard solutions.…”

Section: N and C Compositionsmentioning

confidence: 99%

Black Sea nitrogen cycling and the preservation of phytoplankton δ¹⁵N signals during the Holocene

Fulton¹,

Arthur²,

Freeman³

2012

Global Biogeochemical Cycles

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[1] The stable isotopic compositions of bulk, clay-bound, organic, and compound-specific nitrogen were determined for mid to late Holocene Black Sea sediments from a set of box and gravity cores. The data demonstrate that cyanobacterial N 2 fixation provided $55% of phytoplankton-derived N preserved in the top 1-2 cm of the sediments. Prior to widespread agricultural and industrial development in the catchment, N 2 fixation was more prominent, providing 70-80% of phytoplankton N. Organic and clay-bound nitrogen fractions record different down-core d 15 N trends that reflect phytoplankton and detrital sources, respectively, and in samples with low organic matter content, the clay-bound fraction comprises up to 38% of bulk nitrogen. Compared with bulk samples, pyropheophytin a (Pphe a), which is a chlorophyll a (Chl a) degradation product, provides a more accurate record of changing phytoplankton d

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“…The concentration of NH 4 was analyzed with the salicylate method (Reardon et al 1966) and the concentration of SRP with the molybdate method (Murphy and Riley 1962) on a Shimadzu (Kyoto, Japan) UV-1800 spectrophotometer. The concentrations of NO 3 and chloride were determined on a Shimadzu (Kyoto, Japan) CDD-6A ion chromatograph.…”

Section: Laboratory Analysesmentioning

confidence: 99%

Contraction, fragmentation and expansion dynamics determine nutrient availability in a Mediterranean forest stream

Schiller

Acuña

Graeber³

et al. 2011

Aquat Sci

100

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Temporary streams are a dominant surface water type in the Mediterranean region. As a consequence of their hydrologic regime, these ecosystems contract and fragment as they dry, and expand after rewetting. Global change leads to a rapid increase in the extent of temporary streams, and more and more permanent streams are turning temporary. Consequently, there is an urgent need to better understand the effects of flow intermittency on the biogeochemistry and ecology of stream ecosystems. Our aim was to investigate how stream nutrient availability varied in relation to ecosystem contraction, fragmentation and expansion due to hydrologic drying and rewetting. We quantified the temporal and spatial changes in dissolved nitrogen (N) and phosphorus (P) concentrations along a reach of a temporary Mediterranean forest stream during an entire contraction-fragmentation-expansion hydrologic cycle. We observed marked temporal changes in N and P concentrations, in the proportion of organic and inorganic forms as well as in stoichiometric ratios, reflecting shifts in the relative importance of in-stream nutrient processing and external nutrient sources. In addition, the spatial heterogeneity of N and P concentrations and their ratios increased substantially with ecosystem fragmentation, reflecting the high relevance of in-stream processes when advective transport was lost. Overall, changes were more pronounced for N than for P. This study emphasizes the significance of flow intermittency in regulating stream nutrient availability and its implications for temporary stream management. Moreover, our results point to potential biogeochemical responses of these ecosystems in more temperate regions under future water scarcity scenarios.

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New reactants for the colorimetric determination of ammonia

Cited by 214 publications

References 0 publications

A round-trip ticket: the importance of release processes for in-stream nutrient spiraling

A round-trip ticket: the importance of release processes for in-stream nutrient spiraling

Black Sea nitrogen cycling and the preservation of phytoplankton δ¹⁵N signals during the Holocene

Contraction, fragmentation and expansion dynamics determine nutrient availability in a Mediterranean forest stream

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New reactants for the colorimetric determination of ammonia

Cited by 214 publications

References 0 publications

A round-trip ticket: the importance of release processes for in-stream nutrient spiraling

A round-trip ticket: the importance of release processes for in-stream nutrient spiraling

Black Sea nitrogen cycling and the preservation of phytoplankton δ15N signals during the Holocene

Contraction, fragmentation and expansion dynamics determine nutrient availability in a Mediterranean forest stream

Contact Info

Product

Resources

About

Black Sea nitrogen cycling and the preservation of phytoplankton δ¹⁵N signals during the Holocene