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E Reid, H. M. Hill, I. D. Wilson, eds., Volume 24 in the Methodological Surveys in Bioanalysis of Drags series, The Royal Society of Chemistry, Cambridge, U.K., 1996, 350 pp., £89.50.

(1999). Basic Principles of HPLC and HPLC System Troubleshooting. Instrumentation Science & Technology: Vol. 27, No. 4, pp. 327-327.

A novel method for separation of fatty acid ethyl esters by Centrifugal Partition Chromatography is reported in this paper. Data are first presented for laboratory-scale separations of fatty acid esters derived from cereal oil, primarily oleic, linoleic and linolenic acids, and from fish oil, containing, primarily, icosapentenoic and docosapentenoic acids. The method does not employ column packing resins; long-chain unsaturated fatty acids which are generally susceptible to oxidation on catalytic surfaces are readily purified by CPC. Scale-up design for industrial applications is discussed.

The effect of molecular association upon gel-permeation chromatographic separations is examined. Application of a previously established GPC elution-volume/molar-volume relationship to the study of solvent/solute interactions is discussed. The use of such interactions to improve fractionating ability of GPC columns is described. Application of the GPC technique to fundamental studies of forces involved in intermolecular association is suggested.

The effects of polarity and stereochemistry of oxygen-containing, low-molecular-weight substances upon gel-permeation chromatographic separations are examined. The basis for these separations appears to be differences in molar volume, together with some small adsorptive effects. Recommendation are made for the application of this size-separation technique to the identification of commercially important glycols and to the assignment of sterochemical configurations to low-molecular-weight compounds. It is also suggested that GPC might be useful for the preparative resolution of enantiomer mixtures by first converting them to diastereomers and then making use of the fact that diastereomeric substances can have different molar volumes.

Gel permeation chromatography (GPC) has become the method of choice for the determination of molecular weight distributions of polymeric substances. It offers speed and excellent reproducibility, and provides details of the shape of the distribution at comparatively low cost.

As part of a study of the mechanism of free radical phenylation of aromatic compounds it was necessary to obtain analytically pure standards of several biphenyls which were expected products of the reactions being examined. While most of them could be purchased or readily synthesized by standard, unambiguous methods, two of them could not, these being 2-tert-butylbiphenyl and 3-tert-butylbiphenyl. These two standards were obtained via preparative-scale gas chromatographic separation of a mixture containing biphenyl and 2-, 3-, and 4-tert-butylbiphenyl. After ascertaining that each tert-butylbiphenyl fraction collected was pure, it was necessary to determine which isomeric structure belonged to each fraction. Infrared spectroscopy was chosen because of its simplicity, reliability, and the ready availability of spectra of model compounds.

Examines the subjects of calibration, estimation of molecular weight distribution, fractionation of low molecular weight substances, and recycling chromatography.