Simultaneous determination of functionality type and molar mass distribution of oligo (1,3,6-trioxocane)s by supercritical fluid chromatography

Polymer ◽  
1992 ◽  
Vol 33 (18) ◽  
pp. 3889-3892 ◽  
Author(s):  
Harald Pasch ◽  
Hartmut Krüger ◽  
Helmut Much ◽  
Ulrich Just
Keyword(s):  
Simultaneous Determination ◽  
Supercritical Fluid ◽  
Mass Distribution ◽  
Supercritical Fluid Chromatography ◽  
Molar Mass ◽  
Molar Mass Distribution

Development of a robust SFC method for evaluation of compatibility for a novel antituberculotic fixed-dose combination

2019 ◽  
Vol 11 (13) ◽  
pp. 1777-1787 ◽  
Author(s):  
Valentina Petruševska ◽  
Iva Krtalić ◽  
Andrea Rašić ◽  
Ana Mornar
Keyword(s):  
Simultaneous Determination ◽  
Supercritical Fluid ◽  
Supercritical Fluid Chromatography ◽  
Fixed Dose Combination ◽  
Fixed Dose ◽  
Chromatography Method ◽  
Dose Combination

A fast and simple supercritical fluid chromatography method for the simultaneous determination of two antituberculotic drugs, isoniazid and rifabutin, and their impurities from a new proposed fixed-dose combination (FDC) was developed.

scholarly journals Size-exclusion chromatography of cellulose: observations on the low-molar-mass fraction

Cellulose ◽  
2020 ◽  
Vol 27 (16) ◽  
pp. 9217-9225
Author(s):  
Leena Pitkänen ◽  
Herbert Sixta
Keyword(s):  
Mass Distribution ◽  
Size Exclusion Chromatography ◽  
Mass Fraction ◽  
Molar Mass ◽  
Accurate Determination ◽  
Size Exclusion ◽  
Molar Mass Distribution ◽  
Universal Method ◽  
Exclusion Chromatography

AbstractAccurate determination of molar mass distribution for disperse cellulose samples has proved to be a challenging task. While size-exclusion chromatography coupled to multi-angle light scattering (MALS) and differential refractive index (DRI) detectors has become the most commonly used method for molar mass determination of celluloses, this technique suffers low sensitivity at the low-molar mass range. As discussed here, the universal method for accurate molar mass distribution analysis of cellulose samples not exists and thus thorough understanding on the differences of the various methodological approaches is important. In this study, the focus is in the accurate determination of the low-molar mass fraction. The results obtained by combining the two calibration strategies, MALS/DRI for polymeric region of a cellulose sample and conventional calibration for oligomeric region, was compared to the results obtained using only MALS/DRI (with extrapolation of the curve where signal-to-noise of MALS is low). For birch pulp sample, the results from the two approaches were comparable; it should be highlighted, however, that MALS/DRI slightly overestimates the molar masses at the low-molar-mass region.

scholarly journals On the Recovery of PLP-Molar Mass Distribution at High Laser Frequencies: A Simulation Study

Processes ◽  
2019 ◽  
Vol 7 (8) ◽  
pp. 501 ◽  
Author(s):  
Shaghayegh Hamzehlou ◽  
M. Ali Aboudzadeh ◽  
Yuri Reyes
Keyword(s):  
Mass Distribution ◽  
Simulation Study ◽  
Molar Mass ◽  
Laser Frequency ◽  
Molar Mass Distribution ◽  
Reliable Determination ◽  
Degree Of Branching ◽  
High Laser ◽  
Laser Frequencies

Due to the inherent difficulties in determination of the degree of branching for polymers produced in pulsed laser polymerization (PLP) experiments, the behavior of the degree of branching and backbiting reaction in high laser frequency and relatively high reaction temperatures have not been well-established. Herein, through a simulation study, the validity of different explanations on the recovery of PLP-molar mass distribution at high laser frequencies is discussed. It is shown that the reduction of the backbiting reaction rate at high laser frequency, and consequent decrease in the degree of branching, is not a necessary condition for recovering the PLP-molar mass distribution. The findings of this work provide simulation support to a previous explanation about the possibility of using high laser frequency for reliable determination of the propagation rate coefficient for acrylic monomers.

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