Convenient determination of methoxy groups of methylated melamine-formaldehyde resins by IR spectroscopy

1987 ◽  
Vol 34 (7) ◽  
pp. 2601-2607 ◽  
Author(s):  
Noriyuki Miyauchi ◽  
Toshio Takeshita ◽  
Mitsuru Akashi ◽  
Riyoko Machida
Keyword(s):  
Ir Spectroscopy ◽  
Melamine Formaldehyde ◽  
Methoxy Groups

IR spectroscopy: Suitable method for determination of curing degree and crosslinking type in melamine–formaldehyde resins

2019 ◽  
Vol 136 (25) ◽  
pp. 47691 ◽  
Author(s):  
Stephanie Weiss ◽  
Katharina Urdl ◽  
Hermann A. Mayer ◽  
Edith M. Zikulnig‐Rusch ◽  
Andreas Kandelbauer
Keyword(s):  
Ir Spectroscopy ◽  
Suitable Method ◽  
Melamine Formaldehyde

Determination of Hydroxy Groups in the Modified Epoxy Oligomers Using IR-Spectroscopy

2015 ◽  
Vol 9 (4) ◽  
pp. 411-416 ◽  
Author(s):  
Ostap Ivashkiv ◽  
◽  
Piotr Bruzdziak ◽  
Olena Shyshchak ◽  
Jacek Namiesnik ◽  
...  
Keyword(s):  
Ir Spectroscopy ◽  
Epoxy Oligomers ◽  
Hydroxy Groups ◽  
Modified Epoxy

Development and Validation of an Eco-Friendly and Low-Cost Method for the Quantification of Cefepime Hydrochloride in Powder for Injectable Solution Using Infrared (IR) Spectroscopy

2020 ◽  
Vol 16 (4) ◽  
pp. 456-464
Author(s):  
Danilo F. Rodrigues ◽  
Hérida R.N. Salgado
Keyword(s):  
Ir Spectroscopy ◽  
Low Cost ◽  
Pharmaceutical Preparations ◽  
Potassium Bromide ◽  
Pharmaceutical Products ◽  
Injectable Formulation ◽  
Ich Guidelines ◽  
Lactam Ring ◽  
Development And Validation

Background: A simple, eco-friendly and low-cost Infrared (IR) method was developed and validated for the analysis of Cefepime Hydrochloride (CEF) in injectable formulation. Different from some other methods, which employ organic solvents in the analyses, this technique does not use these types of solvents, removing large impacts on the environment and risks to operators. Objective: This study aimed at developing and validating a green analytical method using IR spectroscopy for the determination of CEF in pharmaceutical preparations. Methods: The method was validated according to ICH guidelines and the quantification of CEF was performed in the spectral region absorbed at 1815-1745 cm-1 (stretching of the carbonyl group of β- lactam ring). Results: The validated method showed to be linear (r = 0.9999) in the range of 0.2 to 0.6 mg/pellet of potassium bromide, as well as for the parameters of selectivity, precision, accuracy, robustness and Limits of Detection (LOD) and Quantification (LOQ), being able to quantify the CEF in pharmaceutical preparations. The CEF content obtained by the IR method was 103.86%. Conclusion: Thus, the method developed may be an alternative in the quality control of CEF sample in lyophilized powder for injectable solution, as it presented important characteristics in the determination of the pharmaceutical products, with low analysis time and a decrease in the generation of toxic wastes to the environment.

Determination of storage stability of the crude extracts of Ganoderma lucidum using FTIR and 2D-IR spectroscopy

2011 ◽  
Author(s):  
Yew Keong Choong ◽  
Su-Qin Sun ◽  
Qun Zhou ◽  
Zakiah Ismail ◽  
Badrul Amini Abdul Rashid ◽  
...  
Keyword(s):  
Ir Spectroscopy ◽  
Ganoderma Lucidum ◽  
Storage Stability ◽  
2D Ir ◽  
Crude Extracts

scholarly journals Mechanism of tubulin–colchicine recognition: a kinetic study of the binding of the colchicine analogues colchicide and isocolchicine

1997 ◽  
Vol 327 (3) ◽  
pp. 685-688 ◽  
Author(s):  
Chantal DUMORTIER ◽  
Qunying YAN ◽  
Susan BANE ◽  
Yves ENGELBORGHS
Keyword(s):  
Rate Constant ◽  
Total Concentration ◽  
Carbonyl Oxygen ◽  
Protein Fluorescence ◽  
Kinetic And Thermodynamic Parameters ◽  
Methoxy Groups ◽  
Displacement Experiments ◽  
Absorbance Changes ◽  
Initial Binding

Colchicide (IDE) is a colchicine (COL) analogue in which the C-10 methoxy group is replaced by a hydrogen atom. Its binding to tubulin is accompanied by a quenching of the protein fluorescence. The fluorescence decrease shows a monoexponential time dependence. The observed rate constant increases in a non-linear way with the total concentration of IDE, allowing the determination of a binding constant for an initial binding site (K1 = 5300±300 M-1) and the rate constant for the subsequent isomerization (k2 = 0.071±0.002 s-1) at 25 °C. The rate constant, k-2, for the reversed isomerization can be determined by displacement experiments. Despite the minor alteration of the C-ring substituent, the kinetic and thermodynamic parameters of binding are substantially different from those of COL itself, for both steps. In isocolchicine (ISO) the carbonyl oxygen atom and the methoxy groups of the C-ring have been interchanged. Its binding to tubulin only results in small fluorescence and absorbance changes. Therefore competition experiments with MTC [2-methoxy-5-(2ʹ,3ʹ,4ʹ-trimethoxyphenyl)-2,4,6-cycloheptatrien-1-one] were performed. ISO competes rapidly and with low affinity with MTC. Fluorimetric titrations of tubulin with MDL (MDL 27048 or trans-1-(2,5 dimethoxyphenyl)-3-[4-(dimethylamino)phenyl]-2-methyl-2-propen-1-one) in the presence and absence of ISO give evidence for the existence of a second, slow-reacting low-affinity site for ISO that is not accessible to MTC or MDL. The relevance of these results for the recognition of COL is analysed.

scholarly journals A multivariate calibration approach for determination of petroleum hydrocarbons in water by means of IR spectroscopy

2010 ◽  
Vol 24 (7-8) ◽  
pp. 444-447 ◽  
Author(s):  
María Dolores Ruiz ◽  
Isneri Talavera Bustamante ◽  
Angel Dago ◽  
Noslen Hernández ◽  
Ana C. Núñez ◽  
...  
Keyword(s):  
Ir Spectroscopy ◽  
Petroleum Hydrocarbons ◽  
Multivariate Calibration ◽  
Calibration Approach
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