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A novel HPLC stationary phase based on fluorinated boron nitride nanotubes (F-BNNTs) incorporated into a monolithic polymeric material was developed. This F-BNNT stationary phase was synthesized to combine the analytical performance of boron nitride nanotubes and the fluorine-based unique selectivity for polar compounds. This F-BNNT column appeared to work well when fluorinated or halogenated compounds were encountered. [ABSTRACT FROM AUTHOR]

A novel column based on silica-containing immobilized fluorinated double-wall carbon nanotubes (F-DWCNTs) was developed. This F-DWCNT stationary phase was synthesized to combine the analytical performance of carbon nanotubes and the fluorine-based unique selectivity for polar compounds. First, the chromatographic support was coated with DWCNTs in a noncovalent way to preserve the sp internal nanotube structure. Second, the DWCNT silica particles were functionalized with fluorine atoms via a solution of Br and BrF at room temperature. This F-DWCNT stationary phase was applied for a variety of separations. The solute retention behaviour was particularly studied under isocratic conditions with a high fraction of ACN in the ACN/water ( v/ v) mobile phase. The retention factors of the solute molecule do not depend linearly on the ACN fraction, but follow a quadratic relationship. This fluorinated stationary phase separated compounds based upon a combination of hydrophobic and polar selective stationary phase interactions. This F-DWCNT appeared to work best when fluorinated or halogenated compounds were encountered. They have longer retention time, better selectivity and work well with high fraction of organic modifiers. This novel stationary phase could thus be a good choice for LC-MS experiments. [ABSTRACT FROM AUTHOR]

Comprehensive gas chromatography is an excellent technique for separating complex mixtures. If, however high-boiling compounds such as polychlorinated biphenyls have to be analysed, proper adjustiment of the temperature of the modulator turns out to be very important in maintaining the performance of the system. It is shown that miniaturisation of the column-to-modulator coupling, adequate selection of the modulating conditions and, for halogenated compound mixtures, the use of a micro electron-capture detector, can solve experimental problems previously encountered with high boilers. [ABSTRACT FROM AUTHOR]