Liquid chromatography under critical conditions: Practical applications in the analysis of amphiphilic polymers

Malik, Muhammad Imran; Ahmed, Hasnat; Trathnigg, Bernd
March 2009
Analytical & Bioanalytical Chemistry;Mar2009, Vol. 393 Issue 6/7, p1797
Academic Journal
Liquid chromatography under critical conditions (LCCC) allows the separation of block copolymers from the corresponding homopolymers as well as the separation of homopolymers according to their functionality. At the transition of exclusion and adsorption mode, the polymer chain becomes “chromatographically invisible,” and thus a separation according to other structural units can be achieved. In the case of block copolymers this situation can be utilized to detect and determine unwanted homopolymers. At critical conditions for the repeat unit, the other block may be eluted in the exclusion or the adsorption regime. In the first case, the block copolymer is eluted before the homopolymer, and its molar mass can be determined as in size-exclusion chromatography. In the second case, it is eluted later than the homopolymer, and the separation of the individual oligomers can be achieved. Advantages and limitations of different approaches in LCCC are discussed. [Figure not available: see fulltext.]


Related Articles

  • Chromatography at the critical condition as a method for polymer analysis. Gorshkov, A. V.; Evreinov, V. V. // Journal of Analytical Chemistry;Oct2009, Vol. 64 Issue 10, p995 

    The potential of critical chromatography in investigating the macromolecule structure of synthetic polymers is considered, such as the determination of the type and number of terminal functional groups, chain topology, and character of group alternation in the chain. New possibilities arising in...

  • Specific Surface of a Stationary Phase in Gas-Liquid Chromatography. Dolgonosov, A. // Journal of Analytical Chemistry;Nov2005, Vol. 60 Issue 11, p1038 

    A model of the surface of a stationary phase in gas-liquid chromatography based on the statistic theory of macromolecules was considered. Quantitative relationships between the capacity of a liquid adsorbent and its molecular structure were determined.

  • The Potential of Polymer Monolithic Capillary Columns for the LC--MS Analysis of Intact Proteins. Wouters, Bert; Vaast, Axel; Treumann, Achim; Ursem, Mario; Ho, Jenny; Hornshaw, Martin; Raes, Marc; Terryn, Herman; Eeltink, Sebastiaan // LC-GC Asia Pacific; 

    LC--MS-based top-down proteomics involves the chromatographic separation and mass-spectrometric characterization of intact proteins without prior enzymatic cleavage into peptides. This article describes the preparation of monolithic reversed-phase (RP) columns with optimized porous structure and...


    Present information on monolithic silica columns. Concept behind the high-performance liquid chromatography method; Properties and characteristics of monolithic silica columns; Suitability of monolithic silica columns for high-speed chromatography, especially in separations involving biological...

  • Development of high-temperature separation techniques for the chemical composition analysis of ethylene - methyl methacrylate block copolymers. Heinz, Lars-Christian; Graef, Sven; Macko, Tibor; Brüll, Robert; Balk, Sven; Keul, Helmut; Pasch, Harald // e-Polymers;Aug2005, p1 

    Ethylene - methyl methacrylate block copolymers are semicrystalline polymers that dissolve in organic solvents only at high temperatures. Accordingly, microstructure analysis by solution methods must be conducted at temperatures above 130°C. For the analysis of block copolymers of different...

  • HPLC technique for quantitation of Chimassorb 944, and its evaluation in analysis of real and standard samples of polyolefins. Farajzadeh, Mir Ali; Eskandar, Shirin Ghochi; Ranji, Ali; Feyz, Elham // Microchimica Acta;Jul2007, Vol. 159 Issue 3/4, p363 

    A high performance liquid chromatography (HPLC) method is presented for the determination of Chimassorb 944 in polymeric matrix. A reversed phase column octadecyl silane (ODS) is used as a stationary phase. As a mobile phase, a mixture of THF:methanol:triethanol amine (90:10:1.5) (v:v:w) is...

  • Size-exclusion chromatography-from high-performance to ultra-performance. Uliyanchenko, Elena // Analytical & Bioanalytical Chemistry;Oct2014, Vol. 406 Issue 25, p6087 

    Size-exclusion chromatography (SEC) enables measurement of the average molecular weights and molecular-weight distributions of polymers. Because these characteristics may, in turn, be correlated with important performance characteristics of plastics, SEC is an essential analytical technique for...

  • Elevated Temperature HPLC: Principles and Applications to Small Molecules and Biomolecules. Zhu, Cuiru; Goodall, David M.; Wren, Stephen A. C. // LC-GC Asia Pacific;Mar2005, Vol. 8 Issue 1, p48 

    The use of elevated and high temperatures in high performance liquid chromatography (HPLC) is reviewed, encompassing the range ambient to 250 �C and with examples covering separations of both small molecules and biomolecules. Generic issues of temperature dependence of retention and plate...

  • Obtaining More Consistent Results. Dolan, John W. // LC-GC North America;Jan2006, Vol. 24 Issue 1, p30 

    The article presents question-and-answer advisory related to the selection of chromatographic condition that maximizes the response for a given compound. The reasons behind the necessity to make several injections of sample before the signal stabilizes are attributed to the presence of at least...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics