Molecular chromatographic studies

Sellergren B, Lespisto M, Mosbach K. Highly enantioselective and substrate-selective polymers obtained by molecular imprinting utilizing noncovalent interactions. NMR and chromatographic studies on the nature of recognition. J Am Chem Soc 1988 110 5853-5860. 

The elucidation and confirmation of structure should include physical and chemical information derived from applicable analyses, such as (a) elemental analysis (b) functional group analysis using spectroscopic methods (i.e., mass spectrometry, nuclear magnetic resonance) (c) molecular weight determinations (d) degradation studies (e) complex formation determinations (f) chromatographic studies methods using HPLC, GC, TLC, GLC (h) infrared spectroscopy (j) ultraviolet spectroscopy (k) stereochemistry and (1) others, such as optical rotatory dispersion (ORD) or X-ray diffraction. 

By far, mass spectrometry (MS) is the most popular detection technique for performing chromatographic studies of essential oils. The use of retention indices, in conjunction with GC/MS studies, is well established. Many laboratories use such procedures in their routine analyses to confirm the identities of unknown components. The identification of components is usually performed by comparing the mass spectra with an MS library. However, a feature of MS for essential oils is that mass spectra are not particularly unique in many cases because of the large numbers of isomers of the same molecular formula, but with different structures, that could exist. Therefore their mass spectra are similar and... 

Based on the plot of the suppressed hydrogens of the molecular under study, the calculation methods of molecular connectivity indices was developed. It has been used in many fields, such as the studies of correlation between structure and physicochemical and pharmacological properties, especially the relationship between structure and retention behavior, and the evaluation of the hydrophobicities of organic compounds by chromatographic methods. 

Molecular statistic and gas chromatographic study of hydrocarbons adsorption on the modified layer silicates and silica in the Henry region... 

M. R.,Thorpe, C. J., Molecular modeling studies and the chromatographic behaviour of oxiracetam and some closely related molecules, /. Comput.-Aided Mol. Des. 1991, 5, 277-284. 

The low-molecular-weight fraction of caustic caramel contains roughly 50 components, but the majority of them are present in only minute proportions. Comparative gas - liquid chromatographic studies conducted by Patey and coworkers on caustic and ammonia caramels showed that the low-molecular-weight fraction of caustic caramel is very poor in components of higher retention time. 

Most of the aforementioned studies represent quantitative structure-retention relationship studies where a series of analytes are used as probes of enantiodiscrimination. There are, however, a number of atomistic molecular modeling studies where the interactions of chiral guests (analytes) with chiral hosts (CSPs) are explicitly determined. Here guest and host are considered as transient diastereomeric complexes and both liquid and gas chromatographic separations have been modeled. 

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