Guo‐Sheng Yang

Shandong University, Jinan, Shandong Sheng, China

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Publications (3)2.67 Total impact

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    ABSTRACT: Molecular mechanics (MM) and molecular dynamics (MD) were used to study the π–π interaction between polynuclear aromatic hydrocarbon (PAH) and pyrene bonded silica phase. There was a good correlation coefficient (r = 0.9330, P = 2.4 × 10) between the logarithmic retention time (ln Tr) of PAHs and −ΔG. However, there was no linearity between the retention time of substituted benzene or naphthalene compounds on pyrene bonded silica stationary phase and ΔG. Quantitative structure–retention relationship (QSRR) had been used to study the relationship of retention time and microstructure. However, by using QSRR for the substituted benzene or naphthalene derivatives, we obtained good correlation coefficient between retention time and microstructures (r = 0.962, F‐test = 104.198). The MM, MD, and QSAR are very useful methods to study the π–π interaction in chromatography.
    No preview · Article · Aug 2007 · Analytical Letters
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    ABSTRACT: The enantiomers of fourteen O,O‐dialkyl‐2‐benzyl‐oxycarbonyl‐aminoaryl‐ methyl‐phosphonates are directly separated on tris(3,5‐dimethyl‐phenylcarbamate) amylose chiral stationary phases, known as Chiralcel AD. All of the selected compounds are baseline separated. The influence of the position and properties of substituents in benzene rings, the length and steric hindrance of alkoxyl groups of the phosphonate ester on the chiral separation are discussed. When the substituents are in the para‐position of the benzene ring, the separation factor is in the following order αp‐NO2 ≫ αp‐Cl > αp‐CH3 > αp‐H > αp‐OCH3. When the same substituent is in a different position of the benzene ring, the order of the separation factor is αp‐Cl > αm‐Cl and αp‐NO2 ≫ αm‐NO2. The values of the separation factor α of the enantiomers where R1 substituent is a hydrogen (R1 = H) are always smaller than those of the enantiomers with p‐Cl substituent, whether R2 was Me, Et, Pr or i‐Pr. Compounds with different substituent R2 and R1 where the substituent is H or p‐Cl, the α values always show an order of αPr > αEt > αMe > αi‐Pr. The chiral discrimination in the amylose tris(3,5‐dimethyl‐phenylcarbamate) was based on π–π interaction and H‐bond interaction.
    No preview · Article · Aug 2006 · Journal of Liquid Chromatography & Related Technologies
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    ABSTRACT: The efficiencies of herbal medicines depend on the amount of active components in them, which could vary significantly in contents. Therefore, the quality control of herbal medicines is a very important issue. This review summarizes the true and false, producing region identification and quality evaluation of herbal medicines by means of their component overlapping infrared spectra (defined as infrared fingerprint spectra or IR FPS). The true and false identification could be performed with specific peaks and their absorption ratios. The producing region and quality of herbal medicines could be determined by analyzing the IR FPS with mathematical classification methods, such as potential component analysis, cluster analysis, and correlation coefficient analysis.
    No preview · Article · Jul 2005 · Analytical Letters