Comparing Gel Permeation Chromatography and Ultrafiltration for the Molecular Weight Characterization of Aquatic Organic Matter

1987 ◽  
Vol 79 (1) ◽  
pp. 43-49 ◽  
Author(s):  
Gary L. Amy ◽  
Michael R. Collins ◽  
C. James Kuo ◽  
Paul H. King
1999 ◽  
Vol 42 (3) ◽  
pp. 281-290
Author(s):  
Edivaldo E Garcia ◽  
Cláudia C.M Kimura ◽  
Ariovaldo C Martins ◽  
Gisele O Rocha ◽  
Jorge Nozaki

Gel permeation chromatography and high performance liquid chromatography were employed for separation and chemical characterization of products isolated from chrome shavings. After enzymatic hydrolysis, the products isolated were peptides of higher molecular weight. Peptides of lower molecular weight and free aminoacids were the main products using sulfuric acid in chrome shavings solubilization. Glycine (17%) , glutamic acid (10.6%) , alanine (9.2%) , and arginine (8.2%) were the principal amino acids found. Phenylalanine(1.8%) was the main aromatic amino acid , while tryptophane was completely absent.


1995 ◽  
Vol 7 (1) ◽  
pp. 55-68 ◽  
Author(s):  
E J Siochi ◽  
S J Havens ◽  
P R Young ◽  
P M Hergenrother

A controlled-molecular-weight LARCr'-CPI 2 poly(amide acid) was synthesized to investigate solution property changes that result from aging'Both dilute and concentrated solutions were aged at five temperatures and periodically analysed over a 33 d period. Various molecular weight parameters were obtained by gel permeation chromatography in combination with differential viscometry. Chemical changes were also followed by Fourier transform infrared spectroscopy. The temperatures used allowed the calculation of the energy of activation associated with changes in weight and number average molecular weights.


1974 ◽  
Vol 7 (3) ◽  
pp. 394-396 ◽  
Author(s):  
E. L. Slagowski ◽  
L. J. Fetters ◽  
Donald McIntyre

2013 ◽  
Vol 641-642 ◽  
pp. 201-205
Author(s):  
Hong Su ◽  
Li Mei Guo ◽  
Lian Yong Wang

polycaprolactone diols (MW=540, 1000, 2000) and citric acid were used as monomers, polycaprolactone-citric acid preformed polymer was preparated firstly by the heating polycondensation, then the preformed polymer was heated and cross-linked to obtain biodegradable elastomeric material. The molecular structure and Molecular weight was proved respectively by 1-HNMR and Gel Permeation Chromatography (GPC). The shape and glass transition temperature (Tg) of polycaprolactone-citric acid polymer was certified by differential scanning calorimetry(DSC). The hydrophilicity of the polymer was evaluated by its contact angle. The polymer’s mechanical property and degradation speed was also investigated.


2011 ◽  
Vol 197-198 ◽  
pp. 21-26
Author(s):  
Ji Hang Li ◽  
Dong Jian Shi ◽  
Na Hu ◽  
Wei Fu Dong ◽  
Jun Feng Li ◽  
...  

In this paper, a novel biodegradable and fluorescent polymer: fluorescein-polylactide (FL-PLA) was synthesized by FL and lactide in the method of ring-opening polymerization with the catalysis of Sn(Oct)2under 130°C . The structure and molecular weight of FL-PLA were characterized by Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (1H-NMR) spectroscopy, and gel permeation chromatography (GPC). The molecular weight of FL-PLA increased from 9.03×103to 21.24×103with decreasing the amount of FL and kept a narrow distribution. The result of differential scanning calorimeter (DSC) showed that Tgincreased from 52 to 72°C with increasing the molecular weight of polymer. Moreover, the average number content of FL in each molecular chain decreased from 0.96 to 0.81 with decrement of the amount of FL. Furthermore, FL-PLA showed the fluorescence property, and the fluorescence intensity could be controlled by the amount of FL. The FL-PLA nanoparticles were prepared by mixing the good and poor solvent, and the diameter was about 3 μm with regular spherical morphology.


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