Separation Of Aromatic Compounds Research Articles

Implication of On-Line Fourier Transform Infrared Detection in the Separation of Aromatic Compounds via Normal-Phase Liquid Chromatography

Abstract Normal-phase liquid chromatography has been used to separate nitrogen heterocyclics and aromatics with polar groups which are known to be present together in solvent refined coal. The identification of the separated components was accomplished by on-line coupling of the Fourier transform infrared spectrometer as a chromatographic detector. The separation of these model compounds was carried out using Li Chrosorb NH2 and CN in series. Chloroform was used as mobile phase. All the compounds could be identified in spite of imcomplete separation in some cases. A suitable interface adapted to the different methods of HPLC and FTIR allowed the detection of about 5 μg per injected compound.

Separation of aromatic compounds by liquid chromatography on diol-bonded phase columns

Retention data of aromatic, polyaromatic, aza-aromatic and phenolic compounds have been measured on diol-bonded silica adsorbents from either laboratory or commercial preparation. Agreement between the data obtained with the two types of phases illustrates the ease of the synthesis of diol-bonded silica. This type of packing material provides a distinct separation of polynuclear aromatic hydrocarbons based on the number of condensed rings. Retention data are compared to similar data measured on amino-bonded silicas. The behavior of the two adsorbents towards polynuclear aromatic hydrocarbons is very similar but the diol phase is less retentive. The importance of substituents effect is determined by varying the degree of substitution on the basic ring structure. Retention of aza-aromatics is independent of the basicity but depends much on the environment of the nitrogen atom. Correlation between retention and the Hammett constants in the case of phenols is compatible with a donor—acceptor retention mechanism.

Separation of aromatic compounds on phenyl-bonded silica

Separation of aromatic compounds on phenyl-bonded silica

Separation of aromatic compounds in lubricant base oils by high performance liquid chromatography

Separation of aromatic compounds in lubricant base oils by high performance liquid chromatography

Separation of aromatic compounds on pellicular anion-exchange resins

Aromatic compounds including phenols, carboxylic acids and aldehydes, can be rapidly separated on pellicular anion-exchange resins in the acetate form by elution with a sodium acetate solution. Like the aromatic carboxylic acids, hydroxybenzaldehydes are held as counter ions in the resin. The affinity of the resin for corresponding anions as well as that for sorbed non-electrolytes is largely influenced by the aromatic ring and non-polar aliphatic substituents. Formation of hydrogen bonds between the resin and phenolic groups is less important.