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Nonionic Polymers – The Acrylic Group
Published in Philip Molyneux, Water-Soluble Synthetic Polymers: Properties and Behavior, 1983
In view of these difficulties, many workers have preferred to determine the PAAm content of the solid or of solutions by nitrogen analysis (the pure polymer contains 19.71% nitrogen), using the Dumas method either alone,1,38 or in conjunction with the Kjeldahl method.65,66 Nonspecific methods such as refractometry are also applicable to these analyses, although eventually they have to be calibrated or checked by one of the absolute methods discussed above. For assaying very dilute solutions (~0.001%), Griot and Kitchener85 used alkaline hydrolysis (presumably to the limit AA-AAm copolymers discussed above in Section III.G), followed by turbidimetry on the colloidal suspension formed on the addition of a cationic surfactant, Hyamine 1622.
Methods for Analysis of Solid Samples
Published in Somenath Mitra, Pradyot Patnaik, Barbara B. Kebbekus, Environmental Chemical Analysis, 2018
Somenath Mitra, Pradyot Patnaik, Barbara B. Kebbekus
The Dumas method is an automated method for the analysis of total nitrogen in solids. A few mg of fine dry soil is placed in a boat and is introduced into a furnace at a temperature above 1000°C. The sample is rapidly heated in a flow of oxygen. Combustion produces products such as CO2, H2O, N2, and Nox. These gases flow into a furnace containing copper at 650°C. Oxygen is removed, and NOx is reduced to N2. Then the effluent passes through traps to eliminate CO2 and H2O. Finally the gas passes into an online gas chromatograph which separates and detects the N2. The whole analysis takes about 3 min.
Quantification of proteins in seaweeds
Published in Bénédicte Charrier, Thomas Wichard, C.R.K. Reddy, Protocols for Macroalgae Research, 2018
Carl Safi, Jelle van Leeuwen, Yvette Telleman, Nicole Engelen-Smit, Lambertus van den Broek, Paulien Harmsen
Total nitrogen content can be measured by Kjeldahl (Section 13.4.1) or Dumas method (Section 13.4.2). Here, the amount of total nitrogen is expressed as % (w/w) dry matter. The NTP conversion factor is calculated by equation A. Nitrogen-to-protein conversionfactor = % (w/w) total protein % (w/w) total nitrogen (A)
Amino acid preparation and recovery from refractory sludge by the oxidative acid hydrolysis process
Published in Environmental Technology, 2022
Wenlong Hui, Jiti Zhou, Ruofei Jin
The moisture content, solid content, and volatile organic matter content of sludge were determined by the gravimetric method. The polysaccharide content was determined by the Dubois method with D-glucose as the standard [35]. The protein content of dry sludge was determined by the micro-Dumas method using BSA (Bovine Serum Albumin) as standard [36]. The element of carbon (C), hydrogen (H), nitrogen (N), oxygen (O), and sulphur (S) were determined by an elemental analyser (VARIO MACRO, Germany). The contents of amino acids were identified using an Automatic Amino Acid Analyser (Biochrom, Britain). With wavelength ranging from 4000 to 400 cm−1, the extracted amino acid compounds were analysed by a Fourier transform infrared (FTIR) spectrometer (Bruckner, Germany) to identify the functional groups at room temperature. Determination of Cr, Ni, Pb, Mn, Cu, As, Cd, and Zn content in crude amino acids by the inductively coupled plasma-optical emission spectroscopy (ICP-OES) method (Optima2000DV, Perkinelmer, America).
Liquid crystal and photophysical properties of laterally fluorinated azo-ester materials
Published in Liquid Crystals, 2022
Salwa J. Kamal, Noordini M. Salleh, H.N.M. Ekramul Mahmud, N. Idayu Zahid
Fourier transform infrared (FT-IR) spectra were recorded on a Perkin Elmer Spotlight 400 spectrometer (Waltham, MA, USA) using the attenuated total reflectance (ATR) method. All data were obtained in the region of 4000–450 cm−1, with a resolution of 4 cm−1 and collected after 4 scans. 1H and 13C nuclear magnetic resonance (NMR) spectra were recorded on a JEOL Lambda 400 MHz spectrometer (Tokyo, Japan) and a Bruker AVN 400 MHz spectrometer (Fällanden, Switzerland) at room temperature using deuterated chloroform (CDCl3) or deuterated dimethyl sulphoxide (DMSO-d6). Elemental analyses of the final compounds were carried out using a Perkin Elmer CHNS/O 2400 Series II Analyser with the classical Pregl-Dumas method, in which samples were combusted in a pure oxygen environment, with the resultant combustion gases measured in an automated fashion. The calibration standard used was acetanilide.
Ozone as a Fungicidal and Detoxifying Agent to Maize Contaminated with Fumonisins
Published in Ozone: Science & Engineering, 2022
Daniel Francis Ribeiro, Lêda Rita D’ Antonino Faroni, Marco Aurélio Guerra Pimentel, Lucas Henrique Figueiredo Prates, Fernanda Fernandes Heleno, Ernandes Rodrigues De Alencar
Evaluation of chemical composition was done before and after each time of exposure to the ozone gas. Analysis of moisture, protein, lipids and ashes contents of maize were performed. The moisture content was determined by the oven-drying method at 105 C for 24 h according to Brasil (2009b). Determination of the protein content of the grains was performed according to AOAC (2005), method 968.06, using the Dumas method, on the Leco FP-528 equipment (LECO Corporation, St. Joseph, MI, USA). For the calculation of the protein content, a conversion factor equivalent to 5.6 was used (Mariotti, Tomé, and Mirand 2008). The total lipid content was determined by the Am 5–04 extraction method, using Ankom Technology’s XT15 Extractor (AOCS 2005). The determination of the ash content of the samples was carried out by the method 945.45 (AOAC 2005) with calcination at 600 C for approximately 4 hours.