Activity coefficients, interfacial tensions and retention in reversed-phase liquid chormatography on LiChrosorb RP-18 with methanol-water mixtures

Hammers, W.E.; Meurs, G.J.; Ligny, C.L. De

doi:10.1016/s0021-9673(00)95857-6

Cited by 47 publications

(26 citation statements)

References 44 publications

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“…Soils SP 14696 (denoted as Soil I) and SP loads lower amount of solutes each time compared to 20697 (Soil II) were purchased from LUFA, Speyer, conventional batch methods. Based on a displaceGermany, and soil GSE 17201 (Soil III) was from ment adsorption model [13] in which the solute is Bayer Landwirtschaftszentrum, Monheim, Germany. distributed between a homogeneous interfacial layer Their main characteristics are listed in Table 1.…”

mentioning

confidence: 99%

Estimation of soil organic partition coefficients: from retention factors measured by soil column chromatography with water as eluent

Liang

Lin

et al. 2002

Journal of Chromatography A

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mentioning

confidence: 99%

Estimation of soil organic partition coefficients: from retention factors measured by soil column chromatography with water as eluent

Liang

Lin

et al. 2002

Journal of Chromatography A

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“…This equation has been widely used to describe the changes of the retention factor k with the methanol fraction of the mobile phase [13,[59][60][61][62][63][64][65][66][67]. It is correct for the majority of analytes in the range of 0.2-0.8 j, but for lower and higher concentrations often nonlinearity occurs [65,[68][69][70][71][72][73], for ionic solutes even at medium modifier concentrations [74][75][76].…”

Section: Resultsmentioning

confidence: 99%

“…incomplete solvation, stronger folding and collapsing of the alkyl chains [69,70,[85][86][87]. Similar conformational changes are not probable on calixarene phases because of their high degree of internal order.…”

Section: Properties Of the Single Interactionsmentioning

confidence: 99%

Characterization of calixarene‐bonded stationary phases

Schneider

Menyes²,

Jira

2010

J of Separation Science

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Calixarene-bonded stationary phases received growing interest in HPLC as stationary phases with special retention characteristics and selectivity. The commercially available unsubstituted and p-tert-butyl-substituted Caltrex(®) columns have been intensively studied and characterized in our workgroup. They can be used as reversed phases, yet they support additional interactions. Especially, their steric, polar and ionic properties differ from conventional alkyl-bonded phases. However, also the hydrophobic interaction shows differences since adsorption and partition interactions on or in a bonded layer of calixarenes are not similar to those of alkyl-bonded layers. The relative strength of the hydrophobic properties of the stationary phases has been found depending on the methanol concentration of the mobile phase. Generally, the dependencies of their interaction strengths on mobile-phase conditions, e.g. the change of the intensity of the hydrogen-bonding abilities with decreasing methanol content, are not similar from phase to phase either. This probably gives calixarene-bonded stationary phases enhanced suitability for analyses at extreme compositions of the mobile phase. An overview about the synthesis, retention and selectivity properties of Caltrex(®) columns is given here.

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“…†Log γ ∞ 1,water was from Hammers et al (1982); log K oc data were the average values taken from Sabljic et al (1995), Kaune et al (1998), and Liu and Qian (1995); the intercepts log k ′ w were obtained from Eq. [6], log k ′ = log k ′ w − S φ, on GSE 17201 reference soil and on Hypersil ODS at 25.0°C.…”

Section: Resultsmentioning

confidence: 99%

“…Multilayer formation of solute molecules on the soil surface is thus precluded. Based on a displacement adsorption model in which the solute is distributed between a homogeneous interfacial layer and the bulk aqueous phase (Hammers et al, 1982), the capacity factor of a solute on the soil can be described as:

\begin{matrix} log k_{normalw}^{'} = log true(n_{1, sorbed} {/ normaln}_{1, water} true) = log true(x_{1, sorbed} n_{2, sorbed} {/ normalx}_{1, water} n_{2, water} true) = log true(n_{2, sorbed} {/ normaln}_{2, water} true) + log true(γ_{1, water}^{\infty} / γ_{1, interface}^{\infty} true) \end{matrix}

where subscript 1 denotes solute, and 2 denotes water. The terms n 1,sorbed (or n 2,sorbed ) and n 1,water (or n 2,water ) are the mole numbers of adsorbed solute (or water) and of solute (or water) in the eluent, respectively.…”

Section: Theoreticalmentioning

confidence: 99%

Prediction of Soil Organic Partition Coefficients by a Soil Leaching Column Chromatographic Method

Liang

Lin

et al. 2001

J of Env Quality

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The soil organic partition coefficient (Koc) is one of the most important parameters to depict the transfer and fate of a chemical in the soil–water system. Predicting Koc by using a chromatographic technique has been developing into a convenient and low‐cost method. In this paper, a soil leaching column chromatograpy (SLCC) method employing the soil column packed with reference soil GSE 17201 (obtained from Bayer Landwirtschaftszentrum, Monheim, Germany) and methanol–water eluents was developed to predict the Koc of hydrophobic organic chemicals (HOCs), over a log Koc range of 4.8 orders of magnitude, from their capacity factors. The capacity factor with water as an eluent k′w could be obtained by linearly extrapolating capacity factors in methanol–water eluents (k′) with various volume fractions of methanol (φ). The important effects of solute activity coefficients in water on k′w and Koc were illustrated. Hence, the correlation between log Koc and log k′w (and log k′) exists in the soil. The correlation coefficient (r) of the log Koc vs. log k′w correlation for 58 apolar and polar compounds could reach 0.987, while the correlation coefficients of the log Koc–log k′ correlations were no less than 0.968, with φ ranging from 0 to 0.50. The smaller the φ, the higher the r Therefore, it is recommended that the eluent of smaller φ, such as water, be used for accurately estimating Koc Correspondingly, the r value of the log Koc–log k′w correlation on a reversed‐phase Hypersil ODS (Thermo Hypersil, Kleinostheim, Germany) column was less than 0.940 for the same solutes. The SLCC method could provide a more reliable route to predict Koc indirectly from a correlation with k′w than the reversed‐phase liquid chromatographic (RPLC) one.

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Activity coefficients, interfacial tensions and retention in reversed-phase liquid chormatography on LiChrosorb RP-18 with methanol-water mixtures

Cited by 47 publications

References 44 publications

Estimation of soil organic partition coefficients: from retention factors measured by soil column chromatography with water as eluent

Estimation of soil organic partition coefficients: from retention factors measured by soil column chromatography with water as eluent

Characterization of calixarene‐bonded stationary phases

Prediction of Soil Organic Partition Coefficients by a Soil Leaching Column Chromatographic Method

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