Determination of the Weight Percentage Gain and of the Acetyl Group Content of Acetylated Wood by Means of Different Infrared Spectroscopic Methods

2008 ◽  
Vol 80 (4) ◽  
pp. 1272-1279 ◽  
Author(s):  
Barbara Stefke ◽  
Elisabeth Windeisen ◽  
Manfred Schwanninger ◽  
Barbara Hinterstoisser
Keyword(s):  
Spectroscopic Methods ◽  
Weight Percentage ◽  
Group Content ◽  
Infrared Spectroscopic ◽  
Acetyl Group ◽  
Weight Percentage Gain

scholarly journals Comparison of two modern infrared spectroscopic methods for the determination of orientation in drawn bulk polymers

2000 ◽  
Vol 19 (2) ◽  
pp. 205-212 ◽  
Author(s):  
Pavel Schmidt ◽  
Miroslav Raab ◽  
Jan Kolařı́k ◽  
Klaus J Eichhorn
Keyword(s):  
Spectroscopic Methods ◽  
Infrared Spectroscopic ◽  
Bulk Polymers

The protonation of the ethylenediphosphinetetraacetate anion and the crystal structure of the bis (hydrogen bromide) of ethylenediphosphinetetraacetic acid

1981 ◽  
Vol 46 (12) ◽  
pp. 3063-3073 ◽  
Author(s):  
Jana Podlahová ◽  
Bohumil Kratochvíl ◽  
Vratislav Langer ◽  
Josef Šilha ◽  
Jaroslav Podlaha
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Structure Determination ◽  
Free Acid ◽  
Hydrogen Bromide ◽  
Carboxyl Groups ◽  
Spectroscopic Methods ◽  
X Ray ◽  
Partial Formation

The equilibria and mechanism of addition of protons to the ethylenediphosphinetetraacetate anion (L4-) were studied in solution by the UV, IR, 1H and 31P NMR spectroscopic methods. A total of six protons can be bonded to the anion. They are added stepwise, first with partial formation of zwitterions containing P-H bonds, which then dissociate with formation of the free acid, H4L, where all four protons are bonded in carboxyl groups. The formation of zwitterions is strongly dependent on the concentration. In the final stage, the acid bonds two additional protons to form the bis-phosphonium cation, H6L2+. A number of isostructural salts containing this cation, H4L.2 HX (X = Cl, Br, I), have been prepared. The X-ray crystal structure determination of the bromide confirmed the expected arrangement. The bromide crystals are monoclinic, a = 578.2, b = 1 425.0, c = 1 046.7 pm, β = 103.07° with a space group of P21/c, Z = 2. The final R factor was 0.059 based on 1 109 observed reflections. The structure consists of H6L2+ cations containing protons bonded to phosphorus atoms (P-H distance 134 pm) and of bromide anions, located in gaps which are also sufficiently large for I- anions in the isostructural iodide. The interbonding of phosphonium cations proceeds through hydrogen bonds, C-OH...O=C, in which the O...O distance is 275.3 pm.

Analytical Method for Measuring SBR Tire Debris in the Environment

1974 ◽  
Vol 47 (1) ◽  
pp. 150-160 ◽  
Author(s):  
Wanda Brachaczek ◽  
W. R. Pierson
Keyword(s):  
Analytical Method ◽  
Soxhlet Extraction ◽  
Spectroscopic Determination ◽  
Infrared Spectroscopic ◽  
Styrene Butadiene ◽  
Tread Rubber

Abstract A procedure has been developed for assaying submilligram amounts of debris from synthetic tire tread rubber in aerosol samples collected from the atmosphere. The procedure involves separation from the bulk of the sample by Soxhlet extraction with orthodichlorobenzene in a stream of oxygen, followed by infrared spectroscopic determination of the rubber hydrocarbon SBR (styrene-butadiene copolymer) in the extract. The procedure was developed to overcome serious difficulties having to do with the small amounts of rubber normally encountered and with losses of SBR during extraction from aerosol samples. These matters are discussed in some detail and some applications of the method are illustrated.

Efficiency of decomposition procedures for the determination of some elements in soils by atomic spectroscopic methods

1998 ◽  
Vol 360 (2) ◽  
pp. 219-224 ◽  
Author(s):  
J. Medved' ◽  
Vladim�r Stre?ko ◽  
Jana Kubov� ◽  
Jozefa Polakovi?ov�
Keyword(s):  
Spectroscopic Methods

scholarly journals Electrochemical design of a new nanosensor based on cobalt nanoparticles, chitosan and MWCNT for the determination of daclatasvir: a hepatitis C antiviral drug

RSC Advances ◽  
2017 ◽  
Vol 7 (2) ◽  
pp. 1118-1126 ◽  
Author(s):  
Shereen M. Azab ◽  
Amany M. Fekry
Keyword(s):  
Hepatitis C ◽  
Health System ◽  
Antiviral Drug ◽  
Cobalt Nanoparticles ◽  
Essential Medicines ◽  
World Health ◽  
Spectroscopic Methods ◽  
Basic Health ◽  
The World

Daclatasvir (DAC) is listed on the World Health Organization's list of essential medicines needed in a basic health system, therefore, electrochemical and impedance spectroscopic methods are necessary.

The Power of Spectroscopic Methods in the Determination of the Relative Orientation of Guest Molecules in a Stretched Polyethylene (PE) Matrix

1985 ◽  
Vol 39 (6) ◽  
pp. 976-979 ◽  
Author(s):  
Joanna Konwerska-Hrabowska
Keyword(s):  
Interaction Energy ◽  
Relative Orientation ◽  
Spectroscopic Methods ◽  
Guest Molecules ◽  
Spectroscopic Measurements ◽  
Host Molecules

Comparison of values for the relative orientation of pyrene guest molecules and PE host macromolecules obtained by spectroscopic measurements and by calculations of the minimum of the interaction energy between the guest and host molecules is presented. Accordance between both results as well as with the Groszek model is found.

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