Analysis of complex samples by coupled-column chromatography

Abstract

Reversed-phase chromatography Is coupled with size-exclusion chromatography to generate a multidimensional chromatographic method for the analysis of complex samples. This method Incorporates three chromatographic steps, the first two of which serve to separate the sample Into fractions which are more readily handled by the final hlgh-resolutlon analytical step. The first fractionation step Is a low-resolution version of the final step and selects compounds with retention times comparable to those of the compounds of analytical Interest. The second fractionation step uses size-exclusion chromatography to select compounds with molecular sizes comparable to those of the compounds of analytical Interest. These first two fractionation steps are coupled on-line. Individual compounds are Identified In a final hlgh-resolutlon, reversed-phase chromatographic step. This multidimensional chromatography system Is applied to the determination of polycyclic aromatic hydrocarbons In coal liquids and oils as an example. With this system, such samples are fractionated and ready for the final analytical step In less than 20 min.

Estimation of chromatographic parameters on two silica‐based columns connected in series under nonaqueous reversed phase liquid chromatographic conditions

“…These discrepancies led to derivation of corrected empirical equations, e. g., (6) or (7), (12) or (13), mobile phase composition dependent, that were proved to be in excellent agreement with the values acquired experimentally.…”

Integrated, multiple-stage chromatographic method for the separation and identification of polycyclic aromatic hydrocarbons in complex coal liquids

“…Goal liquid fractionation procedures have included fractional distillation (1)(2)(3)(4), size-exclusion chromatography (5)(6)(7)(8)(9), solvent extraction (10)(11)(12)(13)(14)(15), adsorption chromatography with alumina and/or silica (16)(17)(18)(19)(20), normal-phase high-performance liquid chromatography (HPLC) (21)(22)(23)(24), and reverse-phase HPLC (25)(26)(27)(28). Analytical methods using combinations of these separation techniques are often required for complete chemical characterization and biological testing of these highly complex mixtures.…”

“…Analytical methods using combinations of these separation techniques are often required for complete chemical characterization and biological testing of these highly complex mixtures. For example, multidimensional coupledcolumn HPLC techniques that produce discrete fractions have been used to analyze polycyclic aromatic hydrocarbons (PAH) in coal liquids (28,29). However, coupled-column HPLC requires modified instrumentation and is impractical for the preparative-scale fractionation of material that is often required for biological testing.…”