Effect of co-modifiers in cyclodextrin-modified mobile phases on the reversed-phase high-performance liquid chromatographic separation of polyaromatic hydrocarbons

Husain, Noni; Christian, Angela Y.; Warner, Isiah M.

doi:10.1016/0021-9673(95)00038-o

Cited by 11 publications

(4 citation statements)

References 11 publications

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“…Using the solute retention time and the void time, k values were determined for all J3-CD concentrations at 25 ~ It has been previously demonstrated by several authors that PAHs such as phenanthrene, anthracene and fluoranthene form with 13-CD a complex with a 1:1 (CD:PAH) stoichiometry [11,13] while pyrene exhibits a 2:1 (CD:PAH) stoichiometry with the same macrocycle [5,18]. Firstly, the retention data were analyzed for fluorene, anthracene, phenanthrene and fluoranthene using the two interaction models assuming a 1:1 stoichiometry (x = 1 in Eqs (5) and (9) Table II.…”

Section: Determination Of Stoichiometry and Association Constants Formentioning

confidence: 99%

“…As well, pyrene interacts strongly with the C18 stationary phase and is not eluted from the column. As a result, workers had to add a co-modifier to the eluent in order to define the stoichiometry and formation constants of the J3-CD-PAH complexes [12,13]. The presence of these co-modifiers led to a modification in the interaction between the macrocycle and the PAHs so that the "true" inclusion mechanism could not be observed.…”

Section: Introductionmentioning

confidence: 95%

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Chromatographic study of PAH-βCD inclusion complexes using a binary mixture and cyano-stationary phase

et al. 2001

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Key WordsColumn liquid chromatography 13-cyclodextrin polycychc aromatic hydrocarbons cyano-stationary phase complex adsorption SummaryThe retention mechanism of a series of five polycyclic aromatic hydrocarbons (PAHs) in highperformance liquid chromatography (HPLC) was investigated using a cyano-bonded silica column and 13-cyclodextrin as mobile phase additive (0 -7.5 mM). Two different models were proposed to investigate the retention mechanism. The first approach considered the interaction of the CD-PAH complex with the stationary phase negligible (i); the second reflected on this interaction (ii). It appeared that model (ii) described more accurately the retention behavior of the five PAHs in this chromatographic system. The stoichiometry of the 13-CD-PAHs inclusion complexes was found to be 1:1 for fluorene, anthracene, phenanthrene and fluoranthene and 2:1 for pyrene. In addition, the association constants were calculated and are discussed in relation to the PAH structures.

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Section: Determination Of Stoichiometry and Association Constants Formentioning

confidence: 99%

Section: Introductionmentioning

confidence: 95%

Chromatographic study of PAH-βCD inclusion complexes using a binary mixture and cyano-stationary phase

et al. 2001

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“…Mobile-phase additives are frequently used in liquid chromatography to enhance the selectivity by introducing additional interaction mechanisms. − When mobile-phase additives are used, retention is still governed by interaction of the free solute with the stationary phase, but the availability of free solute is mediated by interactions with the mobile-phase additive. As a result, this approach can increase column utility and often eliminate the need for multiple specialty columns.…”

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confidence: 99%

“…As a result, this approach can increase column utility and often eliminate the need for multiple specialty columns. For example, cyclodextrins have been used as mobile-phase additives to achieve discrimination for a wide range of solutes including prostaglandins, chiral barbiturates, polynuclear aromatic hydrocarbons, and imiadazole enantiomers . Incorporation of mobile-phase additives also affords a convenient method for the determination of binding or complexation constants. − Binding constants of cyclodextrins to various drugs, anthracene and pyrene, and terpenes 8 have been determined chromatographically by varying the cyclodextrin concentration in the mobile phase.…”

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Liquid Chromatographic Separations with Mobile-Phase Additives: Influence of Pressure on Coupled Equilibria

et al. 2000

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On the basis of equilibrium thermodynamics, pressure can cause a shift in equilibrium for any interaction that exhibits a change in partial molar volume. This shift in equilibrium can be observed in liquid chromatography as a pressure-dependent shift in solute retention. In this paper, the impact of pressure on liquid chromatographic separations with mobile-phase additives is examined from both theoretical and experimental perspectives. The theoretical development for coupled-equilibria separations shown here is general and can be applied to any separation using mobile-phase additives. Predictions indicate that the coupled nature of these equilibria leads to pressure-induced perturbations in partitioning and complexation that can either compete with or complement one another. Using positional isomers and enantiomers as model solutes, experimental retention observations are fully consistent with these predictions, showing the diminution of individual pressure effects for competing cases and enhanced pressure effects for complementary cases. When pressure-induced changes in capacity or retention factor differ between individual solutes, changes in solute selectivity are predicted and observed. Using a C18 stationary phase with beta-cyclodextrin as the mobile-phase additive, solutes studied here exhibit changes in selectivity ranging from - 7 to + 10% for a change in average pressure of approximately 215 bar. Perhaps the most dramatic change in selectivity is observed for the separation of positional isomers where pressure-induced changes in selectivity actually reverse solute elution order.

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Extraction of Parabens from Water Samples Using Cloud Point Extraction with a Non‐Ionic Surfactant with β‐Cyclodextrin as Modifier

Noorashikin

Raoov

Mohamad

et al. 2014

J Surfact & Detergents

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A cloud point extraction process using a silicone non‐ionic surfactant to extract selected parabens compounds from water samples was investigated using reversed phase high performance liquid chromatography. The cloud point extraction process, in the presence of β‐cyclodextrin (β‐CD) as a modifier, is a new extraction process which was optimized with five parameters, i.e. salt concentration, pH of the solution, temperature, surfactant concentration and β‐CD concentration. The developed method with the β‐CD modifier results in an excellent performance on detection of parabens from water samples with limits of detection in the range of 0.017–0.043 μg/L and percentage recoveries from 90.5 to 98.9 %.

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Effect of co-modifiers in cyclodextrin-modified mobile phases on the reversed-phase high-performance liquid chromatographic separation of polyaromatic hydrocarbons

Cited by 11 publications

References 11 publications

Chromatographic study of PAH-βCD inclusion complexes using a binary mixture and cyano-stationary phase

Chromatographic study of PAH-βCD inclusion complexes using a binary mixture and cyano-stationary phase

Liquid Chromatographic Separations with Mobile-Phase Additives: Influence of Pressure on Coupled Equilibria

Extraction of Parabens from Water Samples Using Cloud Point Extraction with a Non‐Ionic Surfactant with β‐Cyclodextrin as Modifier

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