Evaluation of a C18 hybrid stationary phase using high-temperature chromatography

Liu, Y.; Grinberg, Nelu; Thompson, Karen; Wenslow, Robert M.; Neue, Uwe D.; Morrison, Damian; Walter, Thomas H.; O’Gara, John E.; Wyndham, Kevin D.

doi:10.1016/j.aca.2005.08.026

Cited by 52 publications

(29 citation statements)

References 25 publications

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“…Our results are in full agreement with the findings of Liu et al [46]. They used a hybrid C18 stationary phase for the separation of alkyl benzenes and aromatic alcohols and applied temperatures up to 2008C.…”

Section: Xbridge C-18supporting

confidence: 83%

Temperature and pH‐stability of commercial stationary phases

Teutenberg¹,

Hollebekkers²,

Wiese

et al. 2009

J of Separation Science

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Original PaperTemperature and pH-stability of commercial stationary phasesIn this paper, the temperature and pH stability of silica-based RP stationary phases were investigated. Furthermore, nonsiliceous phases like a polymeric column based on polystyrene divinylbenzene and a polybutadiene coated zirconium dioxide column were also included. The columns were heated up to 1508C at dynamic conditions, which means that the eluent consisting of water and methanol (90:10, v/v) was continuously purged through the packed bed. After every 5 h, the columns were cooled down to room temperature and the efficiency was measured by injecting a test sample based on the Neue test. It could be shown that some stationary phases exhibited a very good temperature stability at the test conditions specified above.

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Section: Xbridge C-18supporting

confidence: 83%

Temperature and pH‐stability of commercial stationary phases

Teutenberg¹,

Hollebekkers²,

Wiese

et al. 2009

J of Separation Science

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“…A estabilidade desta FE também foi atestada por Liu et al, 26 que relataram uma perda de 10% na eficiência do butilbenzeno após 1 mês de uso a 200 o C com FM 100% água.…”

Section: Fases Estacionáriasunclassified

Possibilidades e limitações no uso da temperatura em cromatografia líquida de fase reversa

Borges¹,

Bottoli²

2010

Quím. Nova

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Recebido em 16/9/09; aceito em 30/11/09; publicado na web em 8/4/10 POSSIBILITIES AND LIMITATIONS OF USING TEMPERATURE IN REVERSED PHASE LIQUID CHROMATOGRAPHY. High-temperature liquid chromatography (HTLC) is a technique that presents a series of advantages in liquid phase separations, such as: reduced analysis time, reduced pressure drop, reduced asymmetry factors, modified retentions, controlled selectivities, better efficiencies and improved detectivities, as well as permitting green chromatography. The practical limitations that relate to instrumentation and to stationary phase instability are being resolved and this technique is now ready to be applied for routine determinations.Keywords: high temperature liquid chromatography; stationary phase stability; green chromatography. INTRODUÇÃOO termo alta temperatura em cromatografia líquida (High Temperature Liquid Chromatography, HTLC) se refere ao uso de temperaturas entre 40 a 200 o C. O uso da temperatura como variável em cromatografia líquida é recente, embora Antia e Horvath 1 tenham descrito seu uso em 1988. A principal vantagem desta técnica é a redução no tempo de análise, característica que é de grande interesse prático para os usuários de cromatografia. Mas até o momento, esta técnica reside quase exclusivamente no meio acadêmico por causa de algumas limitações, como a falta de instrumentação específica para tal fim e a instabilidade das fases estacionárias. Desta forma, esta revisão se dedica à discussão das vantagens e limitações desta técnica, bem como os avanços recentes quanto à instrumentação e fases estacionárias, os quais devem impulsionar a migração desta técnica para o meio industrial. ASPECTOS TEÓRICOS Influência da temperatura sobre a pressãoA pressão gerada pela passagem de fase móvel (FM) por uma coluna pode ser descrita pela equação de Kozeny-Carman:2,3 ΔP = (ηFL)/(K 0 πr 2 dp 2 ), onde K 0 é a permeabilidade específica, η é a viscosidade da FM, F é a vazão da FM, r é o raio interno da coluna e dp é o diâmetro médio das partículas da fase estacionária (FE) que recheiam a coluna. A viscosidade decresce exponencialmente em função da temperatura, 2,3 assim, o aumento da temperatura permite: a utilização de maiores vazões; o emprego de partículas com menores diâmetros; a utilização de colunas com maior comprimento ou conectadas em série.Um exemplo de como o aumento da temperatura permite o uso de maiores vazões é o trabalho de Yang et al.2 onde uma coluna ZirChrom-PS (50 x 4,6 mm, dp 2,5 μm) utilizada a 25 o C e com FM acetonitrila:água, 25:75 v/v, a uma vazão de 2 mL/min gera uma pressão de 400 bar, alcançando o limite máximo de pressão de um sistema convencional de cromatografia líquida de alta eficiência (High Performance Liquid Chromatography, HPLC). Quando a temperatura é elevada a 150 o C, a pressão é reduzida a 60 bar, permitindo o uso de uma vazão de 14 mL/min sem exceder o limite de pressão da bomba.As micropartículas (dp < 2 μm) têm pequena resistência à transferência de massa a altas vazões. Por isso podem ser utilizadas com pouc...

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“…A number of classes of organic compounds have been separated by SBWC. They include carbohydrates [15][16][17][18], amino acids [15,17,18], alcohols [11,[19][20][21][22][23][24], carboxylic acids [8,15], phenols [8-11, 18, 24-30], anilines [9,18,30], phosphonic acids [17], PTH-amino acids [31][32][33], aldehydes [34], water-soluble vitamins [35], caffeine derivatives [11,14,27,36,37], parabens [10,26,37], barbiturates [10,26,38], steroids [33,[39][40][41][42], model drugs [43][44][45][46], sulfonamides [47,48], flavones [49], triazole fungicides …”

Section: Introductionmentioning

confidence: 99%

Subcritical water chromatography: A green approach to high‐temperature liquid chromatography

Yang¹

2007

J of Separation Science

103

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At temperatures and pressures lower than 374 degrees C and 218 atm, subcritical water has widely tunable properties such as dielectric constant, surface tension, viscosity, and dissociation constant achieved by simply adjusting the temperature with a moderate pressure to keep water in the liquid state. At elevated temperatures, water acts like a weak polar organic solvent. Thus, subcritical water has been used as a green eluent to replace hazardous solvents commonly used as organic modifiers in RPLC. Subcritical water chromatography (SBWC) is capable of separating polar, moderately polar, and even some nonpolar analytes. Most of these low molecular weight solutes are stable at elevated temperatures during a chromatographic run. Some new packing materials are also quite stable and robust at mild temperatures ranging from 80 to 150 degrees C. Advantages of SBWC include the elimination of hazardous organic solvents used in traditional RPLC, rapid analysis time, improved selectivity, temperature-dependent separation efficiency, temperature-programmed elution, and compatibility with both gas- and liquid-phase detectors. In this paper, the technical aspects as well as the applications of SBWC are reviewed. Topics addressed in this review include the unique characteristics of subcritical water, analytes separated by SBWC, packing materials tested for SBWC, the application of GC and LC detection techniques in SBWC, SBWC instrumentation development, temperature effects on SBWC separation, and models developed for separation in SBWC.

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Evaluation of a C18 hybrid stationary phase using high-temperature chromatography

Cited by 52 publications

References 25 publications

Temperature and pH‐stability of commercial stationary phases

Temperature and pH‐stability of commercial stationary phases

Possibilidades e limitações no uso da temperatura em cromatografia líquida de fase reversa

Subcritical water chromatography: A green approach to high‐temperature liquid chromatography

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