A simple, sensitive and selective method for the simultaneous determination of nitrite and nitrate in water samples has been developed. The method is based on ion-exchange separation, online photochemical reaction, and luminol chemiluminescence detection. The separation of nitrite and nitrate was achieved using an anion-exchange column with a 20mM borate buffer (pH 10.0). After the separation, these ions were converted to peroxynitrite by online UV irradiation using a low-pressure mercury lamp and then mixed with a luminol solution prepared with carbonate buffer (pH 10.0). The calibration graphs of the nitrite and nitrate were linear in the range from 2.0 x 10(-9) to 2.5 x 10(-6)M and 2.0 x 10(-8) to 2.5 x 10(-5)M, respectively. Since the sensitivity of nitrite was about 10 times higher than that of nitrate, the simultaneous determination of nitrite and nitrate in the water samples could be efficiently achieved. This method was successfully applied to various water samples--river water, pond water, rain water, commercial mineral water, and tap water--with only filtration and dilution steps.
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http://dx.doi.org/10.1016/j.chroma.2009.01.096 | DOI Listing |
Vet Anim Sci
March 2025
Animal Science Research Department, Fars Agricultural and Natural Resources Research and Education Center, Agricultural Research, Education and Extension Organization (AREEO), Shiraz, Iran.
This study aims to measure the effects of different dietary concentrations of triticale hay (TH) on productive performance, carcass characteristics, microbial protein synthesis (MPS), ruminal and blood variables, and antioxidant power in 40 fattening male Gray Shirazi lambs (BW of 33.2 ± 1.1 kg) over 81 days in a completely randomized design (10 animals/diet).
View Article and Find Full Text PDFACS ES T Water
January 2025
Mechanical Engineering, Faculty of Engineering and Physical Sciences, University of Southampton, Southampton, SO17 1BJ, United Kingdom.
Wet chemical sensors autonomously sample and analyze water using chemical assays. Their internal fluidics are not susceptible to biofouling (the undesirable accumulation of microorganisms, algae, and animals in natural waters) due to the harsh chemical environment and dark conditions; however, the sample intake and filter are potentially susceptible. This paper describes the use of copper intake filters, incorporated to prevent fouling, on two different wet chemical nitrate sensors that each use different variants of the Griess assay (in particular, different nitrate reduction steps) to quantify nitrate concentrations.
View Article and Find Full Text PDFPregnancy Hypertens
January 2025
School of Health Professions, Faculty of Health, University of Plymouth, UK.
Background: Oral health may influence blood pressure control by modulating the abundance and activity of nitrate-reducing bacteria, which are essential for enhancing nitrite and nitric oxide (NO) bioavailability. This study aimed to investigate the oral health and microbiome composition of women with pre-eclampsia (PET) compared to healthy controls (CN).
Methods: Ten PET and eleven CN women participated in this study, respectively.
Sci Total Environ
January 2025
Great Lakes Institute for Environmental Research, University of Windsor, Windsor, ON, Canada. Electronic address:
Upgrading wastewater treatment plants (WWTPs) is a global practice for achieving increasingly stringent nutrient discharge objectives set by governments to accommodate population growth and reduce surface water pollution. However, associated downstream improvements in nutrient conditions are difficult to determine in nearshore regions of large aquatic ecosystems due to complex biophysical processes. We conducted a nine-year water quality study and analyzed the data using linear mixed models (LMMs) within a Before-After-Control-Impact (BACI) framework to assess effects of an upgrade to the Duffin Creek Water Pollution Control Plant (DCWPCP) on surface water nutrient conditions and proliferation of nuisance benthic algae (Cladophora glomerata) in nearshore Lake Ontario.
View Article and Find Full Text PDFEnviron Sci Technol
January 2025
Marine Synthetic Ecology Research Center, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Guangdong Provincial Observation and Research Station for Marine Ranching in Lingdingyang Bay, China-ASEAN Belt and Road Joint Laboratory on Mariculture Technology, State Key Laboratory for Biocontrol, Sun Yat-sen University, Zhuhai 519082, China.
Plants can recruit microorganisms to enhance soil arsenic (As) removal and nitrogen (N) turnover, but how microbial As methylation in the rhizosphere is affected by N biotransformation is not well understood. Here, we used acetylene reduction assay, gene amplicon, and metagenome sequencing to evaluate the influence of N biotransformation on As methylation in the rhizosphere of , a potential As hyperaccumulator. was grown in mining soils (MS) and artificial As-contaminated soils (AS) over two generations in a controlled pot experiment.
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