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A method based on supercritical fluid chromatography is presented which can be used for the determination of cholesterol in certain foods. The method involves the extraction with supercritical carbon dioxide and analysis of the extracts using a capillary column with supercritical carbon dioxide as mobile phase and flame ionization detection. Quantification(More)
The use of micellar electrokinetic capillary chromatography (MECC) for the separation of eleven substituted phenols listed by the United States Environmental Protection Agency as priority pollutants was demonstrated. The effects of the pH and ionic strength of the buffer, and the length of the separation column on resolution were investigated. The retention(More)
The applications of Freon-22 (R22) as a mobile phase and as a modifier in supercritical fluid chromatography were investigated. For the purpose of this investigation, the separation of eleven phenols listed by the United States Environmental Protection Agency as priority pollutants was studied. It was found that the use of neat R22 greatly reduced the(More)
This paper describes the use of the overlapping resolution mapping procedure to optimize the separation of priority pollutants by isocratic, reversed-phase high-performance liquid chromatography. Three classes of pollutants are considered: polycyclic aromatic hydrocarbons, substituted phenols and phthalate esters. The procedure requires only seven(More)
The effect of varying SDS concentration in a micellar electrokinetic capillary chromatographic system (MECC) is investigated. In addition, the introduction of γ-cyclodextrin as modifier to the electrophoretic medium, containing SDS and a phosphate-borate buffer, is shown to give satisfactory separation of the seven selected PAHs. The separation efficiency(More)
The use of mixed surfactants for the separation of nine phenylthiohydantoin amino acids (PTH amino acids) by micellar electrokinetic chromatography (MEKC) was examined. The potential of a mixed surfactant system, consisting of cationic and anionic surfactants, for enhancing the selectivity of MEKC separations was explored. Both sodium dodecyl sulfate (SDS)(More)
Optimization procedures for the reversed-phase separations of six phthalates using the isoselective multisolvent gradient elution (IMGE) system are described. A systematic experimental design has been employed to gather retention data on the compounds in a mixture. The data were then fitted into a second-order polynomial equation and an overlapping(More)
54 sporadic colorectal cancers were analyzed for aberrations in the K-ras oncogene. DNA was extracted from frozen tissues obtained from surgical resection and analyzed for mutations in codons 12, 13 and 61 of the K-ras oncogene using single strand conformation polymorphism analysis (SSCP) and direct sequencing. Point mutations in the K-ras oncogene were(More)
A rapid and simple method is described for the quantitative determination of polycyclic aromatic hydrocarbons in aqueous environmental samples. A microscale on-line supercritical fluid extraction-supercritical fluid chromatography system using carbon dioxide is employed. The extract is analysed using capillary supercritical fluid chromatography with UV(More)