An improved hydrazine reduction method for the automated determination of low nitrate levels in freshwater

Downes, Malcolm T.

doi:10.1016/0043-1354(78)90177-x

Cited by 227 publications

(86 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Nitrite (NO 2 -N) was measured by spectrophotometry after diazotizing with sulfanilamide and coupling with N-(1-naphthyl)-ethylenediamine (Rodier 1996). Ammonium (NH 4 -N) and nitrate were measured with the indophenol-blue method and the automated hydrazine reduction method (Downes 1978), respectively. The same method was used to determine total dissolved nitrogen (TDN) after all nitrogen forms had been oxidized to nitrate with K 2 S 2 O 8 at 121ЊC (Ebina et al 1983).…”

Section: Methodsmentioning

confidence: 99%

Nutrients and organic matter in a glacial river—floodplain system (Val Roseg, Switzerland)

Tockner

Malard

Uehlinger

et al. 2002

Limnology & Oceanography

119

View full text Add to dashboard Cite

Nutrient and organic matter dynamics were evaluated for a glacial river-floodplain system in the Swiss Alps (Val Roseg). Glacial melt water was the primary source of particulate organic and inorganic matter; hillslope groundwater was richest in DOC and SiO 2 ; and pulses in dissolved nitrogen were identified during spring snowmelt. Calculations of temporal coherency revealed that hydrological processes within the catchment-floodplain complex controlled nutrient and organic matter species along the main channel; however, local hydrological and/or biogeochemical processes played a major controlling role in most floodplain channels. DON and NO 3 -N were the only variables that were in average significantly correlated across all sampling sites. Comparisons of measured concentrations and concentrations based on a two end member mixing model indicated that the floodplain served as a major sink for particulate phosphorous and suspended matter but was never a source for nutrients or organic matter. Annual areaspecific export rates from the Val Roseg catchment were 7.6 kg ha Ϫ1 yr Ϫ1 for TOC (47% DOC), 4.3 kg for TP (98% particulate phosphorus), and 4.1 kg for TN (78% NO 3 -N).Quantification of nutrient and organic matter sources, transformations, and sinks at the catchment/floodplain scale is a major challenge in ecology. This is in particular true for remote arctic and high alpine streams that have received much less attention compared to more accessible areas (Milner and Petts 1994;Wissmar et al. 1997). Alpine and arctic streams appear resource limited in terms of both nutrients and organic matter. For example, Lock et al. (1990) showed that the addition of phosphorous to an arctic river resulted in a substantial stimulation of both heterotrophic and autotrophic processes. Robinson and Gessner (2000) demonstrated that nutrient addition accelerated leaf breakdown in a glacial stream. Further, there is strong evidence that zoobenthic communities in glacial streams are not solely structured by temperature and channel stability (cf. Milner and Petts 1994), but are strongly influenced by seasonal shifts in water sources and corresponding availability of nutrients and or-1 Corresponding author (tockner@eawag.ch). AcknowledgementsThis study was supported by a research grant from the Swiss National Science Foundation (SNF 21-49243). We appreciate the field support of Tina Boesch, Birgit Klein, Chris Robinson, Rainer Zah, and Peter Burgherr, and we are especially grateful to Richard Illi and Bruno Ribi for the chemical analyses. We express our sincere thanks to Plenio Testa and his crew at the 'Hotel Roseg' for their hospitality and to the communes of Pontresina and Samedan for providing access to the sampling area. We also appreciate helpful comments by Jürg Zobrist, Edith Kaiser, and Chris Robinson. Thoughtful comments by two anonymous reviewers are gratefully acknowledged.

show abstract

Section: Methodsmentioning

confidence: 99%

Nutrients and organic matter in a glacial river—floodplain system (Val Roseg, Switzerland)

Tockner

Malard

Uehlinger

et al. 2002

Limnology & Oceanography

119

View full text Add to dashboard Cite

show abstract

“…Samples for total P, dissolved P, and particulate P were first digested with potassium persulfate and measured by ascorbic acid methods (Lind 1985;APHA 1998), as were those for soluble reactive P. Total N was measured by alkaline potassium persulfate digestion (D'Elia et al 1977) and the ultraviolet (UV) absorption method (APHA 1998), and nitrate + nitrite N was determined by the hydrazine reduction method (Downes 1978). Dissolved Si was measured following the methods of Wetzel and Likens (1991).…”

Section: 'mentioning

confidence: 99%

Phytoplankton productivity across prairie saline lakes of the Great Plains (USA): a step toward deciphering patterns through lake classification models

Salm

Saros

Fritz

et al. 2009

Can. J. Fish. Aquat. Sci.

View full text Add to dashboard Cite

We investigated patterns of primary production across prairie saline lakes in the central and northern Great Plains of the United States. Based on comparative lake sampling in 2004, seasonal predictors of algal primary productivity were identified within subsets of similar lakes using a combination of Akaike's information criterion (AIC) and classification and regression trees (CART). These models indicated complex patterns of nutrient limitation by nitrogen (N), phosphorus (P), and iron (Fe) within different lake groups. Nutrient enrichment assays (control, + Fe, + N, + P, + N + P) were performed in spring and summer of 2006 to determine if phytoplankton in selected lakes followed predicted patterns of nutrient limitation. Both the comparative lake sampling and experimental results indicated that N limitation was widespread in these prairie lakes, with evidence for secondary P limitation in certain lakes. In the experiments, iron did not stimulate primary production. Our results suggest that given the diverse geochemical nature of these lakes, classification models that separate saline lakes into subsets may be an effective method for improving predictions of algal production.

show abstract

“…18 Also, soluble organic materials, such as amino acids, would interfere with hydrazine-reduction, probably by chelating the Cu(II) catalyst. 19 We examined the effects of these possible interfering species and other nitrogen species, such as ammonia and urea. The results are given in Table 1.…”

Section: Interferences Precision and Accuracymentioning

confidence: 99%

Flow-Injection Analysis Method for the Determination of Nitrite and Nitrate in Natural Water Samples Using a Chemiluminescence NOx Monitor

Kanda

Taira

2003

ANAL. SCI.

View full text Add to dashboard Cite

The determination of nitrite and nitrate in aqueous environmental samples is of considerable interest in research concerning hydrological chemistry, chemical oceanography, and atmospheric chemistry. Nitrate is an essential nutrient which controls the biomass in natural water; the amount also indicates the extent of pollution and eutrophication of the aquatic environment. Nitrite is a nitrogen-cycle intermediate and a useful indicator of the equilibrium state of the oxidative and reductive pathways of the nitrogen cycle. Also, nitric acid and nitrous acid are very important trace constituents of the atmosphere in both the gaseous and particulate phases. Nitric acid is a major NOx sink in photochemical air pollution. Nitrous acid is recognized as a major source of a very reactive hydroxyl radical, which is a key intermediate for all photochemical oxidant formations. These gases and particulates are precursors of acid rain, and are deposited on the ground mainly by wet precipitation, such as rain and snow.Among many analytical methods proposed for the determination of nitrate and nitrite, a widely used method for analyses of natural water samples is based on the reduction of nitrate to nitrite and a subsequent spectrophotometric determination via the Griess reaction, 1-3 which involves the diazotization of sulfanilic acid and successive coupling with 1-naphthylamine. Though numerous modifications have been suggested, primarily based on changing either the reagent being diazotized or coupled, sulfanilamide or sulfanilic acid and N-(1-naphtyl)ethylenediamine are the most popular couples. 4,5 The spectrophotometric method can provide reliable results for natural water samples, but suffers from interferences from suspended and colored substances in the samples. Cox 6 proposed a chemiluminescence analysis technique, which is more highly sensitive and free from these interferences. The technique is based on the chemical reduction of nitrate and nitrite to NO and detection via a chemiluminescence reaction of NO with ozone. Garside 7 first applied this technique to seawater analyses. Braman and Hendrix 8 reported on an application used for environmental water samples. These methods used NaI for reducing nitrite to NO, and iron(II)-molybdate or vanadium(III) for reducing nitrate to NO. The reduction procedures in these methods require highly acidic conditions and/or operation at a relatively high temperature. In the monitoring method of ambient gaseous HNO2, 9 we employed ascorbic acid in a dilute H2SO4 for reducing nitrite to NO. This reagent is easy to handle and the reaction is rapid and quantitative at low nitrite levels. By reducing nitrate to nitrite with an alkaline hydrazine solution, the measurement system was further developed to a gaseous HNO3 monitoring method. 10The coupling of the chemiluminescence detection with a flowinjection technique (FIA) would permit the development of sensitive, precise, rapid, and high throughput methodologies having a wide dynamic range. Aoki and Wakabayashi 11 reported a chemilumine...

show abstract

An improved hydrazine reduction method for the automated determination of low nitrate levels in freshwater

Cited by 227 publications

References 3 publications

Nutrients and organic matter in a glacial river—floodplain system (Val Roseg, Switzerland)

Nutrients and organic matter in a glacial river—floodplain system (Val Roseg, Switzerland)

Phytoplankton productivity across prairie saline lakes of the Great Plains (USA): a step toward deciphering patterns through lake classification models

Flow-Injection Analysis Method for the Determination of Nitrite and Nitrate in Natural Water Samples Using a Chemiluminescence NOx Monitor

Contact Info

Product

Resources

About