Nitrate and organic N analyses with second-derivative spectroscopy

Crumpton, William G.; Isenhart, Thomas M.; Mitchell, Paul D.

doi:10.4319/lo.1992.37.4.0907

Cited by 382 publications

(235 citation statements)

References 8 publications

Supporting

Mentioning

234

Contrasting

Order By: Relevance

“…Total number of coliform bacteria (TNCB) was estimated using the standard method [42]. Total nitrogen and TDN were analyzed by method of second derivative after digestion in persulfate solution [43,44]. The NH 4 -N and NH 3 -N were estimated by phenate method and ion chromatography, respectively, followed by extract filtration of the source water sample through GF/C filters.…”

Section: Water Chemistry Analysesmentioning

confidence: 99%

Stream Health Evaluation Using a Combined Approach of Multi-Metric Chemical Pollution and Biological Integrity Models

Atique

2018

Water

View full text Add to dashboard Cite

Bouchung Stream is a large tributary of the Geum River watershed that is simultaneously affected by wastewater treatment plant effluents and agricultural activities in the watershed area. The focal subject was to diagnose the chemical and biological health of the temperate stream by using a combined approach of the multi-metric water pollution index (WPI) and the index of biological integrity (IBI KR ), using datasets from 2008-2014. Water chemistry analyses indicated seasonal and inter-annual variations mainly linked to the intensity of monsoon rainfall in the watershed, potentially causing the availability of agricultural runoff water. The main events of phosphorus inflow and nitrogen dilutions occurred during July-August. Temporal and spatial heterogeneities were observed and were largely recognizable due to nutrient enrichment and organic matter intensification. Chlorophyll showed weak linear relation to total phosphorus (R 2 = 0.17) but no relation to total nitrogen (p > 0.05). Fish compositions analyzed as trophic/tolerance guilds in relation to water chemistry showed visible decline and modifications. Average WPI site scores ranged from 33-23, indicating an excellent upstream to fair downstream water quality status. Correspondingly, IBI KR scores ranged between 38-28 approximating with WPI site classification, as well as both indices showed higher regression relation (R 2 = 0.90). Fish guild analyses revealed tolerant and omnivore species dominating the downstream, while sensitive and insectivores depleting in approximation with changing water chemistry and was confirmed by the principal component analysis. In addition, the fish guilds meticulously responded to phosphorus inflows. In conclusion, overall stream health and water chemistry analyses indicated continuous chemical and biological degradation influencing the trophic and tolerance fish guilds. Moreover, the combined application approach of WPI and IBI KR could help in better understanding the chemical and biological mechanisms in rivers and streams.

show abstract

Section: Water Chemistry Analysesmentioning

confidence: 99%

Stream Health Evaluation Using a Combined Approach of Multi-Metric Chemical Pollution and Biological Integrity Models

Atique

2018

Water

View full text Add to dashboard Cite

show abstract

“…Total nitrogen (TN) was measured using colorimetry after persulfate digestion (Crumpton et al 1992). Ammonia nitrogen (NH 4 (N) and nitrate nitrogen (NO 3 (N) were measured by Standard Methods (APHA 1985).…”

Section: Chemical Water Quality Analysismentioning

confidence: 99%

Modifications of ecological trophic structures on chemical gradients in lotic ecosystems and their relations to stream ecosystem health

Ji-Woong

Lee

2013

Animal Cells and Systems

View full text Add to dashboard Cite

The objectives of this study were to evaluate how chemical gradients and physical habitats influence trophic dynamics and chemical tolerance in relation to ecological health, based on biological integrity model in the absence of cascading pressures (cascading theory) as a control mechanism of aquatic ecosystems. We conducted physical, chemical, and biological surveys from 76 national streams and rivers of four major watersheds during 2004Á2005 along with surveys of 80 reference streams. Maximum species richness lines (MSRLs) in reference sites vs. regular sampling sites indicated that the third-to fifth-order streams were evidently impaired in the metrics of trophic and tolerant components. These trophic modifications were linked with land-use patterns, which resulted in differences of nutrients (N, P), organic matter contents and the N:P ratios on trophic structures. Overall, these trophic factors influenced ecological health, based on multimetric index of biological integrity model in these systems, so that trophic compositions and tolerance were regulated by bottom-up hypothesis.

show abstract

“…Total phosphorus was measured on a Cary UV-Vis spectrophotometer as PO À4 3 , after digestion with potassium persulfate, using the molybdenum blue method [25]. Total nitrogen samples were digested with alkaline potassium persulfate and analyzed as NO-on a Varian Cary 50 UV-Vis spectrophotometer using second derivative UV spectroscopy [26]. Chlorophyll a was used as a surrogate for phytoplankton biomass, and samples were filtered onto 0.45 mm microcellulose filters, frozen, extracted with HPLC-grade acetone, and measured using a Turner Designs Trilogy fluorometer.…”

Section: Water Sampling and Chemical Analysismentioning

confidence: 99%

Bottom‐up nutrient and top‐down fish impacts on insect‐mediated mercury flux from aquatic ecosystems

Jones

Chumchal

Drenner

et al. 2013

Enviro Toxic and Chemistry

View full text Add to dashboard Cite

Abstract-Methyl mercury (MeHg) is one of the most hazardous contaminants in the environment, adversely affecting the health of wildlife and humans. Recent studies have demonstrated that aquatic insects biotransport MeHg and other contaminants to terrestrial consumers, but the factors that regulate the flux of MeHg out of aquatic ecosystems via emergent insects have not been studied. The authors used experimental mesocosms to test the hypothesis that insect emergence and the associated flux of MeHg from aquatic to terrestrial ecosystems is affected by both bottom-up nutrient effects and top-down fish consumer effects. In the present study, nutrient addition led to an increase in MeHg flux primarily by enhancing the biomass of emerging insects whose tissues were contaminated with MeHg, whereas fish decreased MeHg flux primarily by reducing the biomass of emerging insects. Furthermore, the authors found that these factors are interdependent such that the effects of nutrients are more pronounced when fish are absent, and the effects of fish are more pronounced when nutrient concentrations are high. The present study is the first to demonstrate that the flux of MeHg from aquatic to terrestrial ecosystems is strongly enhanced by bottom-up nutrient effects and diminished by top-down consumer effects. Environ.

show abstract

Nitrate and organic N analyses with second-derivative spectroscopy

Cited by 382 publications

References 8 publications

Stream Health Evaluation Using a Combined Approach of Multi-Metric Chemical Pollution and Biological Integrity Models

Stream Health Evaluation Using a Combined Approach of Multi-Metric Chemical Pollution and Biological Integrity Models

Modifications of ecological trophic structures on chemical gradients in lotic ecosystems and their relations to stream ecosystem health

Bottom‐up nutrient and top‐down fish impacts on insect‐mediated mercury flux from aquatic ecosystems

Contact Info

Product

Resources

About