Selection of molecular descriptors used in quantitative structure-gas chromatographie retention relationships

Dimov, N.; Osman, Abdimajid

doi:10.1016/0003-2670(95)00554-4

Cited by 22 publications

(13 citation statements)

References 23 publications

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“…We also compared our approach to the calculation of retention indices of branched alkenes with approaches proposed by Hu and Zhang [7] and Dimov and Osman [10,11]. Our statistical data (Table III) are of the same order as those obtained by these other authors, but we used a simpler statistical method with a single topological descriptor in the development of our models.…”

Section: Equation Phasementioning

confidence: 99%

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Use of a semi-empirical topological method to predict the chromatographic retention of branched alkenes

et al. 2002

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Gas ch romatog raphy Quantitative structure-retention relationships QSRR Semi-empirical topological method Topological indices Branched alkenes SummaryThe new semi-empirical topological index (lET) previously developed by Heinzen, Soares, and Yunes has been extended to branched alkenes. The main advantage of this method was excellent predictive power and high statistical quality using one topological descriptor only, in comparison with those achieved with a variety of descriptors by multivariate regression techniques and recognition patterns. Another advantage is that this molecular descriptor is related to structural features of the molecule, which enables the cis and trans structures of branched alkenes to be distinguished and highlights the propyl effect -a special steric effect resulting from branching at carbon atoms/? to the dou ble bond. The stabihty and validity of the model generated on squalane (80 ~ was tested by the cross-validation (r2cv = 0.997) technique.

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Section: Equation Phasementioning

confidence: 99%

“…The predictions obtained by use of this technique were in good agreement with predictions achieved by use of multilinear regression techniques. Dimov and Osman [10] developed a descriptor-selection information scheme that was applied to branched alkenes. The equations obtained were formed by two groups of descriptor: 'basic' and 'tuning'.…”

Section: Introductionmentioning

confidence: 99%

Use of a semi-empirical topological method to predict the chromatographic retention of branched alkenes

et al. 2002

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“…The values of 24 global molecular indices and six local indices of 14 equally numbered atoms were determined and those dependent on rotation descriptor values were selected. Global descriptors were then tested for use as basic descriptors [9,10]. Regression analysis was performed with conventional software.…”

Section: Structure Entry and Descriptor Calculationmentioning

confidence: 99%

The solute molecule—Rigid or partially flexible? calculation of benzodiazepineR F values as an example

Dimov

1999

Chromatographia

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SummaryQuantitative structure-retention relationship (QSRR) calculations are currently limited to the ideal case of the isolated solute molecule, i.e. one which retains its original 3D structure after adsorption by the stationary phase. This work shows that because interactions between the solute molecule and the stationary phase release more energy than the energy barrier to rotation of solute bonds, the solute structure can undergo changes enabling better location on or in the stationary phase; descriptor values calculated for the presumed new 3D structures and used in regression calculations might give a better fit between the experimental and calculated retention values. This hypothesis has been checked for 15 benzodiazepines separated by thin-layer chromatography with two mobile phases. The Rv values calculated were statistically more accurate.

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“…QSRRs have been used to obtain simple models to explain and predict the chromatographic behavior of various classes of compounds [5 -13]. For example, Dimov and Osman used QSRRs to relate the chromatographic retention of 38 isoalkanes to their molecular structure features [14]. Mekenyan et al have derived a linear quantitative retention structure model in GC for 41 alkylbenzenes [15].…”

Section: Introductionmentioning

confidence: 99%

Prediction of supercritical fluid chromatographic retention factors at different percents of organic modifiers in mobile phase

Fatemi

Malekzadeh

Shamseddin

2009

J of Separation Science

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In this work quantitative structure-retention relationship models were developed to predict the solute retention factors in supercritical fluid chromatography (SFC) in various organic modifiers. Data set contains the retention data of 35 various organic compounds in 0, 2, 4 and 6% of methanol in mobile phase. The obtained 140 data points were divided into training, internal and external test sets which have 93, 23 and 24 retention data. The diversity validation test was performed on data the set to ensure that the structure of the training and/or test sets can represent those of the whole ones. Descriptors which were selected by stepwise multiple linear regression (MLR) methods are: the percent of organic modifier in mobile phase, salvation connectivity index chi-2, salvation connectivity index chi-5, H attached to heteroatom, the 2(nd) structural information content and polarity parameter. These descriptors were used as features in generation of linear and non-linear models using MLR and artificial neural network (ANN) methods, respectively. The root mean square error of MLR model are 0.116, 0.138 and 0.260 for training, internal and external test sets, respectively, while these values are 0.036, 0.097 and 0.244 for ANN model, respectively. Comparison between these values and other statistical parameters obtained from these two models reveals the credibility of ANN in prediction of solute retention factors in SFC.

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Selection of molecular descriptors used in quantitative structure-gas chromatographie retention relationships

Cited by 22 publications

References 23 publications

Use of a semi-empirical topological method to predict the chromatographic retention of branched alkenes

Use of a semi-empirical topological method to predict the chromatographic retention of branched alkenes

The solute molecule—Rigid or partially flexible? calculation of benzodiazepineR F values as an example

Prediction of supercritical fluid chromatographic retention factors at different percents of organic modifiers in mobile phase

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