scholarly journals Temperature Gradient Interaction Chromatography: A Perspective

2021 ◽  
Author(s):  
Lian R. Hutchings ◽  
Antonella Pagliarulo
Keyword(s):  
Liquid Chromatography ◽  
Temperature Gradient ◽  
Molar Mass ◽  
Reversed Phase ◽  
Normal Phase ◽  
Branched Polymers ◽  
Size Exclusion ◽  
Advanced Technique ◽  
High Molar Mass ◽  
Exclusion Chromatography

AbstractThe application of temperature gradient interaction chromatography (TGIC) as an advanced technique for the characterisation of polymers is discussed, in comparison to other liquid chromatography techniques and in particular the ubiquitous size exclusion chromatography. Specifically, the use of reversed-phase TGIC for the interrogation of complex branched polymers and normal-phase TGIC for characterisation of high-molar mass end-functionalised polymers is highlighted.

Separation of Liquiritin by Two-Dimensional Liquid Chromatography

2012 ◽  
Vol 455-456 ◽  
pp. 1232-1238 ◽  
Author(s):  
Jing Xiang Cong ◽  
Shao Yan Wang ◽  
Hong Gao
Keyword(s):  
Liquid Chromatography ◽  
Reversed Phase ◽  
Normal Phase ◽  
Size Exclusion ◽  
Two Dimensional ◽  
Target Compound ◽  
Reversed Phase Chromatography ◽  
Complex Samples ◽  
Exclusion Chromatography ◽  
Licorice Extract

Two-dimensional liquid chromatography (2DLC) is an important technology for the separation and analysis of complex samples. Liquiritin, an important active component in licorice, was chosen as the target compound and it was separated by three kinds of off-line 2DLC, i.e. size exclusion chromatography × reversed phase chromatography, normal phase × reversed phase chromatography and reversed phase chromatography × reversed phase chromatography (SEC×RP, NP×RP and RP×RP). The chromatographic conditions were selected and the 2D systems were combined. The results show that it is feasible to separate Liquiritin from licorice extract using 2DLC. Among the 2D modes mentioned above, the highest purity of Liquiritin was obtained in the RP×RP mode, and the concentration of Liquiritin was increased most significantly in the NP×RP mode.

scholarly journals Coupling of Size-Exclusion Chromatography to Liquid Chromatography/Mass Spectrometry for Determination of Trace Levels of Thifensulfuron-Methyl and Tribenuron-Methyl in Cottonseed and Cotton Gin Trash

2000 ◽  
Vol 83 (3) ◽  
pp. 651-659 ◽  
Author(s):  
James J Stry ◽  
Jennifer S Amoo ◽  
Steve W George ◽  
Teresa Hamilton-Johnson ◽  
Ellen Stetser
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Size Exclusion Chromatography ◽  
Reversed Phase ◽  
Size Exclusion ◽  
Liquid Chromatography Mass Spectrometry ◽  
Exclusion Chromatography ◽  
Tribenuron Methyl ◽  
Cotton Gin

Abstract Size-exclusion chromatography (SEC) was coupled to reversed-phase liquid chromatography/mass spectrometry for the determination of thifensulfuron-methyl and tribenuron-methyl in cottonseed and cotton gin trash. The limit of quantitation was 20 parts per billion (ppb), and the limit of detection was 6 ppb. The analytes were extracted by homogenization in a buffer solution. The extracts underwent a solvent exchange into methanol and were injected onto an SEC column. As the analytes eluted from the SEC column, the eluate was diverted onto a reversed-phase column for additional separation of the analytes and their detection via mass spectrometry. This method is unique because the samples are not cleaned up before analysis, the analytes are injected in methanol, and the entire analysis is completed in 30 min. Average recoveries and standard deviations for thifensulfuronmethyl and tribenuron-methyl in cotton gin trash were 91 ± 6% and 88 ± 5%, respectively. Average recoveries and standard deviations for thifensulfuron-methyl and tribenuron-methyl in cottonseed were 91 ± 11% and 99 ± 12%, respectively. This is an effective method for the detection and determination of thifensulfuron-methyl and tribenuronmethyl in cotton.

scholarly journals Living with Breakthrough: Two-Dimensional Liquid-Chromatography Separations of a Water-Soluble Synthetically Grafted Bio-Polymer

Separations ◽  
2020 ◽  
Vol 7 (3) ◽  
pp. 41
Author(s):  
H.C. van de Ven ◽  
J. Purmova ◽  
G. Groeneveld ◽  
Tijmen S. Bos ◽  
A.F.G. Gargano ◽  
...  
Keyword(s):  
Liquid Chromatography ◽  
Reversed Phase ◽  
Water Soluble ◽  
Size Exclusion ◽  
Two Dimensional ◽  
Reaction Products ◽  
Grafting Reaction ◽  
Exclusion Chromatography ◽  
The One ◽  
Strong Injection

In this study, we evaluate the use of various two-dimensional liquid chromatographic methods to characterize water-soluble, synthetically grafted bio-polymers, consisting of long poly(acrylic acid) chains and short maltodextrin grafts. The confirmation of the presence of grafting and the estimation of its extent is challenging. It is complicated by the limited solubility of polymers, their structural dispersity and chemical heterogeneity. Moreover, the starting materials (and other reagents, reaction products and additives) may be present in the product. Reversed-phase liquid chromatography (RPLC), hydrophilic-interaction liquid chromatography (HILIC) and size-exclusion chromatography (SEC) were used to characterize the product, as well as the starting materials. Additionally, fractions were collected for off-line characterization by infrared spectroscopy and mass spectrometry. The one-dimensional separation methods were found to be inconclusive regarding the grafting question. Breakthrough (the early elution of polymer fractions due to strong injection solvents) is shown to be a perpetual problem. This issue is not solved by comprehensive two-dimensional liquid chromatography (LC × LC), but information demonstrating the success of the grafting reaction could be obtained. SEC × RPLC and HILIC × RPLC separations are presented and discussed.

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