Experimental Determination of the Molar Absorption Coefficient of n -Hexane Adsorbed on High-Silica Zeolites

ChemPhysChem ◽  
2017 ◽  
Vol 18 (17) ◽  
pp. 2374-2380 ◽  
Author(s):  
Giorgio Gatti ◽  
Diana F. Olivas Olivera ◽  
Vittoria Sacchetto ◽  
Maurizio Cossi ◽  
Ilaria Braschi ◽  
...  
Keyword(s):  
Absorption Coefficient ◽  
Experimental Determination ◽  
Molar Absorption Coefficient ◽  
High Silica ◽  
High Silica Zeolites

Determination of the molar absorption coefficient for the infrared absorption band of CO2in rhyolitic glasses

2004 ◽  
Vol 89 (2-3) ◽  
pp. 301-306 ◽  
Author(s):  
Harald Behrens ◽  
Nathalie Tamic ◽  
Francois Holtz
Keyword(s):  
Absorption Band ◽  
Absorption Coefficient ◽  
Infrared Absorption ◽  
Molar Absorption Coefficient ◽  
Infrared Absorption Band

The determination of ammonia in sea water

1967 ◽  
Vol 47 (2) ◽  
pp. 271-280 ◽  
Author(s):  
B. S. Newell
Keyword(s):  
Absorption Coefficient ◽  
Sea Water ◽  
Molar Absorption Coefficient ◽  
English Channel ◽  
Precise Method ◽  
Chloramine T ◽  
Oxidation Of Ammonia

A sensitive, specific and precise method for the determination of ammonia in sea water is presented. The method depends upon the oxidation of ammonia by chloramine-T and subsequent coupling with phenol to produce indophenol blue in an n-hexanol extract. Molar absorption coefficient ca 84,000. Values of ammonia measured in samples from the English Channel are given and the effect of freezing on samples for ammonia analysis is discussed.

scholarly journals Experimental Determination of the Uncertainty of the Absorption Coefficient of Crystalline Silicon

2015 ◽  
Vol 77 ◽  
pp. 170-178 ◽  
Author(s):  
Carsten Schinke ◽  
P. Christian Peest ◽  
Karsten Bothe ◽  
Jan Schmidt ◽  
Rolf Brendel ◽  
...  
Keyword(s):  
Absorption Coefficient ◽  
Experimental Determination ◽  
Crystalline Silicon

scholarly journals Spectral characteristics of 5-hydroxymethylfurfural as a related substance in medicinal products containing glucose

Pharmacia ◽  
2019 ◽  
Vol 66 (3) ◽  
pp. 121-125
Author(s):  
Nataliia Hudz ◽  
Dmytro Leontiev ◽  
Piotr P. Wieczorek
Keyword(s):  
Absorption Coefficient ◽  
Quantitative Determination ◽  
Spectral Characteristics ◽  
The United States ◽  
Molar Absorption Coefficient ◽  
Future Application ◽  
Medicinal Products ◽  
Scientific Publications ◽  
Related Substance

Objectives: To study 5-hydroxymethylfurfural (5-HMF) spectral characteristics aiming at their future application in analytical procedures and their validation for the determination of 5-HMF in liquid products containing glucose after sterilization. Method: Direct spectrophotometric method for the determination of 5-HMF using the molar absorption coefficient at the absorption maximum (284 nm). Results and discussion: aqueous 5-HMF solutions have strong absorption in the ultraviolet range below 310 nm and give two absorption maxima at wavelengths of 229–230 nm and 284 nm. An excellent linear relationship between absorbance and 5-HMF concentration was observed in the concentration range of 2.0–10.0 mg/l. The linear dependence passes through the origin. The molar absorption coefficients of 5-HMF were determined and found to be 3007 mol−1•L•cm−1at 229–230 nm and 16070 mol−1•L•cm−1at 284 nm. The use of the molar absorption coefficient of 5-HMF stated in the Pharmacopeia of the United States of America for determining 5-HMF in polydextrose (16830 mol−1·L·cm−1at 283 nm) gives recovery results for model solutions of reference substance of 5-HMF that are acceptable from the point of view of the requirements of the State Pharmacopeia of Ukraine for methods of quantitative determination of impurities. However, other values of the molar absorption coefficient (17000 and 22700 mol−1•L•cm−1) given in the scientific publications are unsuitable for the quantitative determination of 5-HMF as an impurity in medicinal products. Conclusion: The molar absorption coefficient (16830 mol−1•L•cm−1at 284 nm) may be used to quantify 5-HMF as an impurity in medicinal products containing glucose. For a specific medicinal product, a full validation of the analytical procedure of the 5-HMF determination is required taking into account the composition of this product.

Determination of the molar absorption coefficient of fluorescein sodium

1992 ◽  
Vol 54 (1) ◽  
pp. 143-144 ◽  
Author(s):  
P.M. Boets ◽  
Hans Van Vreeswijk ◽  
Alfons Verhaegen ◽  
Jan Den Hartigh ◽  
Jaap A. Van Best
Keyword(s):  
Absorption Coefficient ◽  
Molar Absorption Coefficient ◽  
Fluorescein Sodium

scholarly journals MONITORAMENTO DO CORANTE PARAROSANILINA EM AMOSTRAS BIOLÓGICAS

2018 ◽  
Vol 35 (3) ◽  
pp. 147
Author(s):  
Humberto Da Silva Junior ◽  
Gutto Raffyson Silva De Freitas ◽  
Diogo Roberto Ferreira Néri ◽  
Francisco Régis Da Silva Pereira ◽  
Robson Fernandes De Farias ◽  
...  
Keyword(s):  
Absorption Coefficient ◽  
Significant Role ◽  
Biological Samples ◽  
Molar Absorption Coefficient ◽  
Gram Positive ◽  
Chemical Substances ◽  
Analytical Curve

Pararosaniline dye (P) is a pigment which has a significant role in analysis of chemical substances and gram-positive and negative bacteria, as well as other microorganisms. Potentiometric essays of P have shown that the colorant is a weak monoprotic acid (pKa= 8,78);and the spectrophotometry allows to estimate its molar absorption coefficient as 1,48x104 mol-1 cm-1 L. The analytical curve for a determination of P has linearity between 7,36x10-6 and 7,36x10-5 mol L-1, and the methodology was application in biological samples.

scholarly journals Surfactant Enhanced-Spectrophotometric Determination of Uranium (VI) at Trace Levels by Using Eriochrome Black T as a Chelating Agent

2017 ◽  
Vol 36 (3) ◽  
pp. 37 ◽  
Author(s):  
Ramazan Gürkan ◽  
Halil İbrahim Ulusoy ◽  
Mehmet Akçay
Keyword(s):  
Absorption Coefficient ◽  
Cationic Surfactant ◽  
Spectrophotometric Method ◽  
Tap Water ◽  
Bathochromic Shift ◽  
Molar Absorption Coefficient ◽  
Benzene Derivative ◽  
Eriochrome Black T ◽  
Lake Water Sample

A sensitive and relatively selective spectrophotometric method is proposed for the rapid determination of uranium using Eriochrome Black T (EBT) being a 2,2’-dihydroxy azo benzene derivative metal indicator in the presence of cationic surfactant of N-cetyl N,N,N-trimethylammonium bromide (CTAB). The complex formation reaction between EBT and uranyl ion, UO2 2+ is instantaneous in presence of NH3/NH4Cl buffer at pH 9.5 and the absorbance as analytical signal remains stable for over 6 h. CTAB as cationic surfactant and polyethylene glycol p-(1,1,3,3-tetramethylbutyl)-phenyl ether, octyl phenol ethoxylate (Triton X-100) as nonionic surfactant are used for improving the sensitivity and solubility of the analytical system, respectively. The proposed method allows the determination of uranium in the concentration range of 0.025-2 μg mL–1 with a molar absorption coefficient of 92440.60 L mol–1 cm–1 and Sandell’s sensitivity of 2.92 μg cm2- in micellar medium while it allows the determination of uranium in the concentration range of 0.25-2.5 μg mL–1 with a molar absorption coefficient of 57019.44 L mol–1 cm–1 and Sandell’s sensitivity of 4.74 μg cm2- at 565 nm in water. The method has a detection limit of 4.60 μg L–1 (CDL: 3Sb/m) at an analytical measurement wavelength of 637 nm with a bathochromic shift of 72 nm. The selectivity of chelating reagent was improved by the use of a mixture containing ethylenediaminetetraacetic acid (EDTA), sulfosalycylic acid and NaF as masking agent. The proposed method has been successfully applied to the determination of uranium at trace levels in different environmental water samples such as tap-water, natural springwater and river-water. The precision (with coefficient of variation of 1.85%) and the accuracy obtained were highly satisfactory. In order to test the accuracy and validation of the method, the certified reference material (TMDA-70; fortified lake water sample) was also analyzed. It was found that the found and the certified values were in good agreement for validating the surfactant enhanced-spectrophotometric method.

Determination of the molar absorption coefficient for the second overtone of an OH stretching mode of Z-9-otadecen-1-ol

1995 ◽  
Vol 9 (2) ◽  
pp. 221-224 ◽  
Author(s):  
Y. Liu ◽  
M.A. Czarnecki ◽  
Y. Ozaki ◽  
M. Suzuki ◽  
M. Iwahashi
Keyword(s):  
Absorption Coefficient ◽  
Molar Absorption Coefficient
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