A Comparison of the Retention of Homologous Series and Other Test Solutes on an Ods Column and a Hypercarb Carbon Column

Möckel, H. J.; Braedikow, A.; Melzer, H.; Aced, Gaby

doi:10.1080/01483919108049334

Cited by 43 publications

(23 citation statements)

References 15 publications

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“…Apart from hydrophobic interaction, also polar interaction can dominate the analytestationary phase interaction. Some groups have observed an increase in retention on PGC with an increased number of polar groups to the analyte (Tanaka et al 1991;Hennion et al 1995;Möckel et al 1991). The presence of underivatized silanol groups on alkyl bonded silica phases may also cause polar interactions e.g.…”

Section: Characteristics Of Pgcmentioning

confidence: 96%

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Porous graphitic carbon sorbents in biomedical and environmental applications

Michel

Buszewski

2009

Adsorption

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This review is written as a privilege of the work of Professor Mietek Jaroniec on surface phenomena, adsorption, chromatographic separations, chemistry of conventional and ordered nanoporous materials.The problems of the porous graphitic carbon (PGC) application in analytical field are presented. Special attention is paid on possibilities of use PGC as a specific sorbent and packing material for selective isolation and analytes enrichment from complex matrices by means of liquid-solid extraction techniques (SPE, SPME, MSPD) and as particular stationary phase in analytical chromatographic columns. Surface and adsorption properties as well as a unique mechanism of retention on porous graphitized carbon sorbents are described. As supplement the examples of application in biomedical and environmental area are added.

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Section: Characteristics Of Pgcmentioning

confidence: 96%

“…alkylbenzenes) has been studied on PGC by many researchers, e.g. Kriz et al (1994) and Möckel et al (1991). It was found that non-polar analytes were strongly retained on PGC.…”

Section: Retention Of Non-polar Analytes and Geometric Isomersmentioning

confidence: 98%

Porous graphitic carbon sorbents in biomedical and environmental applications

Michel

Buszewski

2009

Adsorption

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“…Here, the opposite behavior was observed where the more polar analytes were the most retained. A linear increase in distribution (extrapolated to pure water as the mobile phase) with the number of hydroxyl and carboxylic acid groups added to polar mono-, di-, and trisubstituted aromatic derivatives [1] or for substituted chlorobenzenes [3] has been reported. By plotting log k versus the number of sulphate groups according to the equation first suggested by Martin [26]: log k = log ko + ~ n (2) a linear relationship was obtained, where n is the number of groups in a homologous series (normally n-alkylbenzenes and n-alkyl homologues), log ko is the intercept and retention for an unsubstituted solute molecule, and ~ is the slope of the relationship and includes instrumental parameters and experimental conditions such as the nature of the substituent groups, etc.…”

Section: Effect Of Buffering Agentmentioning

confidence: 98%

“…An equivalent expression for the relation between chromatographic retention and degree of substitution by homologues groups can be obtained by relating the total change in Gibbs free energy, AG~ using the expression Aa~ = R Tin(k~;25) (3) where R is gas constant, Tis absolute temperature (in Kelvin) and ~ is phase ratio of the chromatographic column. The total change in free energy is the sum of the individual free energies associated with hydrophobic, AG~ polar, AG~ electrostatic (charged induced dipole), AG~ and, solvent, AG~ interactions.…”

Section: Effect Of Buffering Agentmentioning

confidence: 99%

Retention studies of sulphated glycosaminoglycan disaccharides on porous graphitic carbon capillary columns

Koivisto¹,

Stefansson

2003

Chromatographia

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SummaryThe retention behaviour of highly polar and charged disaccharide isomers has been studied on porous graphitic carbon columns and experimental parameters were varied over wide a range, including concentration and type of mobile phase constituents as well as temperature. The hydrophilic and anionic sugar analytes were highly retained on this stationary phase compared to the octadecyl-derivatized silica packings more commonly used. E.g., an increase in retention with polarity of a solute and with temperature was observed. By isotherm measurements and nonlinear fitting of Langmuirian expressions to the experimental data the graphite surface appeared homogeneous with only one kind of active adsorption site for these kinds of compound which was furthermore supported by the linearVan't Hoff plots obtained byvarying the temperature. The gain in free energy was found to be entropically driven after determination of the AH ~ and AS ~ values. However, enthalpy-entropy compensation behavior was not met.

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“…This material provides increased retention of highly polar compounds probably due to charge-induced interaction of the polar analyte with the polarizable graphite surface, in addition to having enhanced selectivity towards aromatic moieties imparted by flat sheets of sp 2 -hybridized carbon atoms at the surface [35,36,37]. It has also been shown that the PGC material provides higher retention for hydrophobic compounds as compared to silica-based C 18 materials [38,39]. Furthermore, this material is reported to be highly stable within the pH range 0-14, to be stable at high temperatures, and shows no swelling or shrinkage, so it can therefore withstand pressures of at least 400 bars [40].…”

Section: Stationary and Mobile Phase Considerationsmentioning

confidence: 98%

Sensitive biomonitoring of phthalate metabolites in human urine using packed capillary column switching liquid chromatography coupled to electrospray ionization ion-trap mass spectrometry

Holm

Solbu

Molander

et al. 2004

Analytical and Bioanalytical Chemistry

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A rapid and sensitive method for the determination of the phthalate monoesters monoethyl phthalate (MEP), monobutyl phthalate (MBP), monobenzyl phthalate (MBzP) and monoethylhexyl phthalate (MEHP), in human urine, using packed capillary column liquid chromatography coupled to electrospray quadrupole-ion trap mass spectrometry (ESI-QITMS(n)) has been developed. Sample volumes of 200 microL of deconjugated and diluted urine were loaded onto a precolumn of 30 mmx0.32 mm I.D. packed with Hypercarb 5 microm particles, using a sample carrier consisting of acetonitrile/water (15/85, v/v, adjusted to pH 2 using HCl) with a flow rate of 20 microL/min. Backflushed elution onto a 100 mmx0.32 mm I.D. analytical column packed with 5 microm Hypercarb particles was conducted using a tetrahydrofuran/water gradient where both solvents contained 10 mM ammonium acetate, at a flow rate of 4 microL/min. Determination of the monophthalates was achieved within 8 min. Ionization was performed in the negative mode and the analytes were observed as [M-H](-) at m/ z=193.1, 221.1, 255.1 and 277.0 for MEP, MBP, MBzP and MEHP, respectively. Quantification was performed in the multiple reaction monitoring (MRM) mode monitoring the fragments at m/ z=121.1, 177.0, 183.0 and 233.0 for MEP, MBP, MBzP and MEHP, respectively. The method was validated over the concentration range 2.5-125 ng/mL in pretreated urine samples, corresponding to 25-1250 ng/mL untreated urine, yielding correlation coefficients in the range 0.996-0.999. The within-assay ( n=6) and between-assay ( n=6) repeatabilities were in the range 4.0-18% and 4.8-15% RSD, respectively. The mass limits of detection were in the range 32-70 pg, corresponding to concentration limits of detection of 1.6-3.5 ng/mL of untreated urine.

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A Comparison of the Retention of Homologous Series and Other Test Solutes on an Ods Column and a Hypercarb Carbon Column

Cited by 43 publications

References 15 publications

Porous graphitic carbon sorbents in biomedical and environmental applications

Porous graphitic carbon sorbents in biomedical and environmental applications

Retention studies of sulphated glycosaminoglycan disaccharides on porous graphitic carbon capillary columns

Sensitive biomonitoring of phthalate metabolites in human urine using packed capillary column switching liquid chromatography coupled to electrospray ionization ion-trap mass spectrometry

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