Gas chromatographic properties of immobilized poly(ethylene glycol) stationary phases

Cigánek, Miroslav; Dressler, M.; Teplý, J.

doi:10.1016/0021-9673(91)85027-d

Cited by 8 publications

(5 citation statements)

References 13 publications

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“…Strong chemical immobilization is also responsible for enhanced thermal stability of the prepared sol−gel PEG columns that can be operated at elevated temperatures up to 320 °C and higher. This operating temperature clearly surpasses the maximum operating temperatures recommended for conventionally coated PEG phases (200−275 °C). , Figure represents one such chromatogram illustrating separation of the Grob test mixture on a sol−gel PEG column.…”

Section: Resultsmentioning

confidence: 89%

“…Despite such advantages, PEG phases are not as widely used in GC practice as the polysiloxane phases. The deficiencies of conventional column technology − with respect to stationary-phase immobilization especially for polar stationary phases such as PEGs , coupled with unfavorable phase characteristics such as low oxidation stability, low thermal stability, phase degradation at low column temperatures, , and high minimum working temperature for certain PEGs 15 (e.g., ∼70 °C for Carbowax 20M) appear to be the major shortcomings in using PEGs as stationary phases. Most of these drawbacks can be eliminated by developing effective methods for the immobilization of PEG stationary phases, and many methods have been put forward to accomplish this. − A majority of these methods employ free radical cross-linking reactions for the immobilization of the stationary phases.…”

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confidence: 99%

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Sol−Gel Poly(ethylene glycol) Stationary Phase for High-Resolution Capillary Gas Chromatography

et al. 2003

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A sol-gel chemistry-based method was developed for the preparation of highly stable capillary gas chromatography (GC) columns with surface-bonded poly(ethylene glycol) (PEG) stationary phase. Through a single-step procedure, it concurrently provided column deactivation, stationary-phase coating, and chemical immobilization of the coated film. Sol-gel reactions were carried out within fused-silica capillaries that were filled with properly designed sol solutions containing two sol-gel precursors, two different triethoxysilyl-derivatized poly(ethylene glycol)s, two sol-gel catalysts, and a deactivation reagent. Hydrolytic polycondensation reactions led to the formation of a sol-gel coating chemically bonded to the inner walls of the capillary. A number of sol-gel coated fused-silica capillary columns were prepared using sol-gel-active PEG derivatives. These columns demonstrated many inherent advantages, the main being the strong anchoring of the coating to the capillary wall resulting from chemical bonding with the silanol groups on the fused-silica capillary inner surface. This chemical bonding yielded strongly immobilized PEG coatings with outstanding thermal stability (up to 320 degrees C). To our knowledge, such a high thermal stability has not been achieved so far on conventionally prepared PEG GC columns. Sol-gel PEG columns provided excellent chromatographic performances: high number of theoretical plates, excellent run-to-run and column-to-column reproducibility, and pronounced selectivity for a wide range of test solutes. Using n-octadecane as a test solute (k = 7.14), an efficiency value of 3200 theoretical plates/m was obtained on a 10 m x 0.25 mm i.d. fused-silica capillary column. Five sol-gel PEG columns provided RSD values of 1.09% for column efficiency (solute, n-octadecane), 1.37% for retention factor (solute, n-octadecane), and 0.9% for separation factor (for solute pair o- and p-xylene). In five replicate measurements using the same column, RSD values of less than 0.50% for the retention time and 1.36% for retention factor (k) were obtained.

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Section: Resultsmentioning

confidence: 89%

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confidence: 99%

Sol−Gel Poly(ethylene glycol) Stationary Phase for High-Resolution Capillary Gas Chromatography

et al. 2003

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“…Immobilization of the stationary phase is generally achieved by bonding the polymer chain to the support. This immobilization process is initiated by free radicals which are produced by heat [1][2][3][4][5] , chemical initiators such as azocompounds [6][7][8] , peroxides [9][10][11][12][13] or ozone 14,15 , and ionizing radiation such as electrons 16 , gamma radiation 17,18 and low-temperature plasmas 19 . All these methods have been successfully applied to produce immobilized nonpolar silicone phases within capillary columns.…”

Section: Introductionmentioning

confidence: 99%

Preparation of thermostable poly(ethylene glycol) using thermal treatment in sealed system

Cardoso¹,

Copetti²,

Schwerz³

et al. 2000

J. Braz. Chem. Soc.

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O trabalho descreve um método rápido para a preparação de Carbowax 20M imobilizada sobre suporte, através do uso de tratamento térmico em forno convencional. O processo de extração com solventes remove a fase estacionária não imobilizada de poli(etileno glicol) (PEG) do suporte e a diferença de massa antes e após a extração fornece o percentual extraído e, consequentemente, o percentual total imobilizado. O tratamento térmico a 250 °C por 10 horas mostrou que a imobilização reduziu a atividade do material e aumentou o número de pratos (N) e a resolução (Rs), enquanto o fator de retenção (k) reduziu. Desta forma, a separação na coluna com material tratado é mais rápida e mais eficiente. A rapid method is described for preparation of support -bonded Carbowax 20M columns packing using a conventional furnace to heat the packing. Solvent extraction of the stationary phase removes the non-immobilized poly(ethylene glycol) (PEG) from the support and the difference between final and initial weight provides the total percent extracted and, consequently, the total percent immobilized. Treatment of the packing material at 250 °C for 10 h. reveals that the immobilization reduces the material activity and increases the plates number (N) and resolution (Rs) while the retention factor (k) is decreased. Thus, separations with this treated column are faster and display higher efficiency.

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“…Another way to improve stationary phase stability is by crosslinking reactions which increase the polymer molecular mass. These immobilization processes, which involve bonding between the chains with possible bonding to the support 2 , are usually initiated by free radicals produced by heat 3,4 , chemical initiators such as peroxides 5,6 , azo compounds 7,8 or ozone 9 , low temperature plasmas 10 , or by ionizing radiation from accelerated electrons 11 or from gamma irradiation [12][13][14][15][16][17] .…”

Section: Introductionmentioning

confidence: 99%

Gamma radiation effects on polydimethylsilane stationary phases for use in packed-column gas chromatographic analyses

Adaime¹,

Santos²,

Facchin³

et al. 1999

J. Braz. Chem. Soc.

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Este trabalho estudou os efeitos da radiação gama como indutora da imobilização de fases estacionárias líquidas de polidimetilsilicones usadas para separações cromatográficas em colunas recheadas. Testes de extração em solventes mostram que doses moderadas de radiação gama (80-140 kGy) produzem imobilização (90%) da maioria dos polidimetilsilicones testados em suportes do tipo Chromosorb, apesar do efeito da massa molecular ser importante. A estabilidade térmica também aumenta significativamente, possibilitando o uso de altas temperaturas sem perdas por volatilização. Espectros no infravermelho confirmam a presença de fase estacionária no suporte após testes de estabilidade térmica e após lavagem exaustiva com solventes em coluna cromatográfica. O comportamento cromatográfico das fases imobilizadas é igual ou melhor do que o das fases não-irradiadas, exceto no caso de altas doses (300 kGy) de radiação gama. As colunas preparadas com polimetilsilicones imobilizados por radiação gama podem ser usadas com sucesso em análises onde a contaminação da coluna por compostos de alto ponto de ebulição exigem frequente recuperação da mesma. Gamma radiation induced immobilization of several polydimethylsilane liquid stationary phases for use in packed-column gas chromatographic separations has been studied. Extraction tests show that moderate doses of gamma radiation (80-140 kGy) are sufficient to produce significant (90%) immobilization of most polydimethylsilanes onto Chromosorb supports, although a molecular mass effect is seen. Thermal stability also increases significantly with radiation dose, suggesting higher temperature use with smaller volatility losses. Infrared spectra confirm the continued presence of the stationary phase on the support after thermal stability tests and after exhaustive in-column washing. The column chromatographic behavior of the immobilized phases is equal to or better than that of the unirradiated phases, except for higher doses (300 kGy) of gamma-radiation. Columns prepared from gamma-immobilized polydimethylsilane have been used successfully in analyses where column contamination from high boiling materials requires frequent column recuperation.

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Gas chromatographic properties of immobilized poly(ethylene glycol) stationary phases

Cited by 8 publications

References 13 publications

Sol−Gel Poly(ethylene glycol) Stationary Phase for High-Resolution Capillary Gas Chromatography

Sol−Gel Poly(ethylene glycol) Stationary Phase for High-Resolution Capillary Gas Chromatography

Preparation of thermostable poly(ethylene glycol) using thermal treatment in sealed system

Gamma radiation effects on polydimethylsilane stationary phases for use in packed-column gas chromatographic analyses

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