An atmospheric pressure microwave digestion method has been developed for the combined analysis of total phosphorus and Kjeldahl nitrogen in complex matrices. In comparison to the digestion steps in EPA Methods 365.4 (total phosphorus) and 351.x (Kjeldahl nitrogen), this method requires less time, eliminates the need for a catalyst, and reduces the toxicity of the waste significantly. It employs a microwave-assisted digestion step, using refluxing borosilicate glass vessels at atmospheric pressure. Traditionally, this method has a time-consuming sample preparation step and generates toxic waste through the use of heavy metal catalysts. These advantages are gained by the combination of a high boiling point acid (sulfuric acid) and the application of focused microwave irradiation, which enhances the digestion process by direct energy coupling. NIST standard reference materials 1572 (citrus leaves), 1577a (bovine liver), and 1566 (oyster tissue) and tryptophan were analyzed to validate the method. Phosphorus concentrations were determined by the colorimetric ascorbic acid method outlined in EPA Method 365.3. Kjeldahl nitrogen concentrations were determined using EPA Method 351.1. The results of the analyses showed good precision and are in excellent agreement with the NIST published values for both elements.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1021/ac960133w | DOI Listing |
J Anim Physiol Anim Nutr (Berl)
January 2025
Chair of Special Food Chemistry, Technische Universität Dresden, Dresden, Germany.
Insects are used as an alternative sustainable, protein-rich ingredient in fish, pet, pig and poultry diets. The significant difference between insect meals and common protein sources is the content of chitin. The nitrogen contained in chitin, which makes up 6.
View Article and Find Full Text PDFSci 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 PDFIntegr Environ Assess Manag
January 2025
División de Estudios de Posgrado e Investigación, Tecnológico Nacional de México/IT de Culiacán, Culiacán, Sinaloa, México.
Eutrophication is one of the most relevant concerns due to the risk to water supply and food security. Nitrogen and phosphorus chemical species concentrations determined the risk and magnitude of eutrophication. These analyses are even more relevant in basins with intensive agriculture due to agrochemical discharges.
View Article and Find Full Text PDFPlants (Basel)
January 2025
Integrated Crop Production Research Unit, Regional Center of Agricultural Research of Agadir, National Institute of Agricultural Research, Avenue Ennasr, BP 415 Rabat Principale, Rabat 10090, Morocco.
(L.) Skeels is a unique endemic species in Morocco, renowned for its ecological characteristics and socio-economic importance. In Morocco, recent years have seen an exacerbation of the harmful effects of climate change, leading to an alarming decline in the natural regeneration of this species in its original habitats.
View Article and Find Full Text PDFChemosphere
January 2025
Laboratory of Water, Biodiversity and Climate Change (EauBiodiCc), Faculty of Sciences Semlalia, University Cadi Ayyad, Marrakech, Morocco; National Centre for Studies and Research on Water and Energy (CNEREE), University Cadi Ayyad, Marrakech, Morocco. Electronic address:
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!