nitrogen determination Articles

  • Nitrogen Determination in Tobacco

    Nitrogen Determination in Tobacco according to the Kjeldahl Method It is considered that flavour and taste of smoke is correlated with the nitrogenous constituents. Accordingto Indian Central Tobacco Reseach Institute (CTRI) fluecured tobacco containing 1.6 to 2.3 % total nitrogen gives the most satisfying smoke, whereas the acceptable limit of total nitrogen is 1.0-3.0 %. High ...


    By BÜCHI Labortechnik AG

  • Determination of Ammonia and Nitrogen

    Customer: CAE Grand Ouest, France CAE is a laboratory of the Veolia Group located in Western France. The laboratory is specializing in environmental analysis, especially in water and soil analysis. Application: Determination of Ammonia and TKN in waste water and soil Total Kjeldahl Nitrogen (TKN) and Ammonia are common parameters for the evaluation of ...


    By BÜCHI Labortechnik AG

  • Selective nitrogen determination methods related to Kjeldahl

    KjelMaster System K-375 / K-376, KjelDigester K-449, Scrubber K-415 85 % of the world’s nitrogen demand for fertilizer is primarily derived from ammonia in the form of urea, ammonium nitrate, phosphate and sulfate. Ammoniacal components can also be found in soil, sludge and bio waste. In those sample matrices, a mixture of several nitrogen containing compounds as urea, nitrogen from ...


    By BÜCHI Labortechnik AG

  • Ammonium, nitrate, and total nitrogen determination in fly ash

    Fly ash is a by-product of the combustion of pulverized coal and is composed of small particles. The composition of the fly ash may vary considerably, however, all fly ashes contain substantial amounts of silicon dioxide (SiO2), aluminum oxide (Al2O3) and calcium oxide (CaO). Nowadays, air pollution control standards require a separation of flue gas before being released to the atmosphere. Fly ...


    By BÜCHI Labortechnik AG

  • TKN determination in water and waste water (Total Kjeldahl Nitrogen)

    Colorimetric determination of TKN (Total Kjeldahl Nitrogen) in water and waste water according to the Kjeldahl method The determination of TKN (total Kjeldahl nitrogen) in water and waste water is a routine procedure for quality assurance and inspection. Here, a reliable procedure for the colorimetric TKN determination in water, according to ISO 5663, AOAC 973.48, and EPA 351.3 is ...


    By BÜCHI Labortechnik AG

  • How to Achieve Low Detection and Quantification Limits for the Nitrogen Determination with Kjeldahl

    Kjeldahl is one of the most commonly used techniques to determine the protein content in food and feed samples or the nitrogen content in soil, sludge, and water samples. The detection and quantification limits are important characteristics of analytical methods. The impact of the concentration of boric acid, the addition of potassium chloride, and the concentration of the titration solution on ...


    By BÜCHI Labortechnik AG

  • Introducing a New ASTM Method for the Determination of Total Nitrogen, and TKN by Calculation, in Water Samples

    The USEPA Clean Water Act (CWA) requires national approval for all methods used for CWA compliance. There are approved methods for the determination of inorganic nitrogen (NO3-N, NO2-N, and NH3-N), and for organic nitrogen (TKN – NH3-N)2. There are no EPA approved methods for the determination of total nitrogen although it is a required parameter in many USEPA permits, including monitoring ...

  • Nitrogen determination in diphtheria and tetanus toxoids according to Pharmacopoeia using back titration and boric acid titration

    KjelMaster System K-375 / K-376, KjelDigester K-449, Scrubber K-415 Nitrogen and total protein determination in pharmaceutical products are described in the European Pharmacopoeia (Ph. Eur.) and in the Pharmacopoeia of the United States (USP). Therein, different titration techniques are specified. The Ph.Eur. is using back titration in the presence of the indicator methyl red mixed ...


    By BÜCHI Labortechnik AG

  • Nitrogen analysis of pharmaceutical excipients

    Customer: Butterworth Laboratories, United Kingdom Wilh nearly 40 years' experience, Butterworth Laboratories remains an independent UK con¬tract analytical service providing Method Development, Method Validation, Stability Testing and OC Testing to the pharmaceutical, medical device and chemical industries. They work in part¬nership with clients who not only recognize expertise ...


    By BÜCHI Labortechnik AG

  • TKN determination in water and waste water

    Determination of TKN (Total Kjeldahl Nitrogen) in Water and Waste Water according to the Kjeldahl Method. The determination of TKN in water and waste water is a routine procedure for quality assurance. A simple and fast procedure for the TKN determination in water, according to ISO 5663, AOAC 973.48 and EPA 351.3, is introduced below. The sample is digested with sulfuric acid and the ...


    By BÜCHI Labortechnik AG

  • How to Determine Aquatic Humic Substances

    Aquatic Humic Substances (AHS) result from the decomposition of plant and animal residues and are found in soil, sediment, and water. They are widespread in nature and are mostly comprised from naturally occurring dissolved organic matter in water. AHSs are an important component in water systems, particularly as they relate to the potential fate of chemicals in the aquatic environment. For ...


  • An approach for determining urban concentration increments

    A simple approach for accurately estimating an urban concentration increment on top of the regional background for urban areas in Europe is presented. The method operates by establishing a functional relationship between the concentration increment and the local meteorological situation, the city characteristics, the urban emissions and the background concentrations. In the current study, the ...


    By Inderscience Publishers

  • Implementation of an automatic and miniature on-line multi-parameter water quality monitoring system and experimental determination of chemical oxygen demand and ammonia-nitrogen

    An automatic, miniature and multi-parameter on-line water quality monitoring system based on a micro-spectrometer is designed and implemented. The system is integrated with the flow-batch analysis and spectrophotometric detection method. The effectiveness of the system is tested by measuring chemical oxygen demand (COD) and ammonia-nitrogen in water. The results show that the modified system ...


    By IWA Publishing

  • Biodegradability of Dissolved Organic Nitrogen: Adaptation of the BOD Test

    To prevent eutrophication in receiving waters, many astewater treatment plants are being firected by regulatory agencies to achieve very low levels of total nitrogen (3-4 mg/L TN or lower) in the effluent. Dissolved organic nitrogen (DON) component is included within these total nitrogen limits. The regulations assume that DON is completely biodegradable, and therefore needs to be included in any ...

  • Modeling organic nitrogen conversions in activated sludge bioreactors

    For biological nutrient removal (BNR) systems designed to maximize nitrogen removal, the effluent total nitrogen (TN) concentration may range from 2.0 to 4.0 g N/m3 with about 25–50% in the form of organic nitrogen (ON). In this study, current approaches to modeling organic N conversions (separate processes vs. constant contents of organic fractions) were compared. A new conceptual model of ON ...


    By IWA Publishing

  • Algae biomass cultivation in nitrogen rich biogas digestate

    Because microalgae are known for quick biomass growth and nutrient uptake, there has been much interest in their use in research on wastewater treatment methods. While many studies have concentrated on the algal treatment of wastewaters with low to medium ammonium concentrations, there are several liquid waste streams with high ammonium concentrations that microalgae could potentially treat. ...


    By IWA Publishing

  • The effect of ammonia stress on nitrogen metabolism of Ceratophyllum demersum

    The objective of this paper was to determine the effect of total ammonia N concentration and pH on the N metabolism of Ceratophyllum demersum and to evaluate the stress caused by inorganic N enrichment in the water column on submersed macrophytes. In this experiment, pH values were carefully controlled to distinguish between the effects of un‐ionized NH3 and ionized NH4+. The results showed ...


    By John Wiley & Sons, Ltd.

  • CFD modelling of nitrogen injection in a longwall gob area

    This paper describes computational fluid dynamics (CFD) simulations conducted to investigate the effectiveness of N2 injection in an active panel and a sealed longwall gob area to prevent and suppress spontaneous heating of coal using various injection locations and flow rates. In the active panel simulations, a single longwall panel with a bleederless ventilation system was ...


    By Inderscience Publishers

  • Assessment of Nitrogen and Phosphorus Environmental Pressure at European Scale

    In surface water bodies, the increase in nutrient concentration above the natural background levels enhances the productivity, causing the phenomenon of eutrophication (Nixon, 1995). The euthrophication has been identified as a major cause of impaired water quality of rivers, lakes and estuaries (EEA, 2001; EEA, 1999; Carpenter et al. 1998; Meybeck, 1982). Agriculture is considered the main ...


  • A mesocosm study using four native Hawaiian plants to assess nitrogen accumulation under varying surface water nitrogen concentrations

    Accumulation of nitrogen (N) by native Hawaiian riparian plants from surface water was measured under a controlled experimental mesocosm setting. Four species, Cladium jamaicense, Cyperus javanicus, Cyperus laevigatus, and Cyperus polystachyos were tested for their ability to survive in coconut fiber coir log media with exposure to differing N ...


    By IWA Publishing

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