Abstract: A chromatographic apparatus includes two chromatographic columns configured to perform chromatography. The apparatus further includes a primary valve disposed upstream of the first chromatographic column and the second chromatographic column. The primary valve selectively switches between a first position in which the pump is in fluid communication with a first path that includes the first chromatographic column and a second position in which the pump is in fluid communication with a second path that includes the second chromatographic column. The apparatus also includes a first and a second sample injection port associated with said first and second columns, respectively, and at least one detector. The apparatus is configured such that flow from the column in the selected path goes to said at least one detector without passing through the other column.

Abstract: Methods and apparatus for analyzing a sample using at least one detector are disclosed.

Abstract: Methods and apparatus for analyzing a sample using at least one detector are disclosed.

Abstract: Pump priming systems and chromatography systems containing the same are, disclosed. Methods of making and methods of using pump priming systems are also disclosed. In conventional chromatography instrumentation, pump priming is performed in a manual mode where the operator manually opens a mechanical valve and uses a syringe to move liquid through the pump until the lines and the pump are filled with liquid.

Abstract: Methods and apparatus for analyzing a sample using at least one detector are disclosed.

Abstract: A gas adsorbent system includes a molded gas adsorbent within a housing. The molded gas adsorbent is disposed in the housing so that shifting is prevented without adhering the gas adsorbent to the housing, for example, by completely filling the housing. The gas adsorbent may include activated zeolite 13X. The gas adsorbent may be formed from a polymer solution such as polysulfone, and contain an organic binder.

Abstract: A method of making a gas adsorbent comprises dissolving a polymer in one or more first solvents to form a polymer solution; mixing an inorganic adsorbent with the polymer solution to form a precursor; molding the precursor; and leaching the first solvents from the precursor with a second solvent.

Abstract: A gas adsorbent is made by dissolving a polymer in one or more first solvents to form a polymer solution; mixing an inorganic adsorbent with the polymer solution to form a precursor; molding the precursor; and leaching the first solvents from the precursor with a second solvent.

Abstract: A process for the purification of nucleosides, and more particularly to a selective solvent extraction method for purifying protected nucleosides. In the purification process, solid particles of protected nucleosides are selectively washed to remove undesirable polar and/or non-polar impurities, while leaving the solid particles substantially undissolved.

Abstract: A titania bound ion exchange composition is prepared by admixing crystalline sodium titanate and a hydrolyzable titanium compound and then drying the titania bound crystalline sodium titanate. The dried titania bound ion exchange composition is subjected to optional compaction and calcination steps to improve the physical strength of the titania bound composition.

Abstract: A chemically modified mica composite formed by heating a trioctahedral mica in an aqueous solution of sodium chloride having a concentration of at least 1 mole/liter at a temperature greater than 180 degrees Centigrade for at least 20 hours, thereby replacing exchangeable ions in the mica with sodium. Formation is accomplished at temperatures and pressures which are easily accessed by industrial equipment. The reagent employed is inexpensive and non-hazardous, and generates a precipitate which is readily separated from the modified mica.

Abstract: In the synthesis of 1,1,1,3,3-pentafluoropropane (R-245fa), a mixture of R-245fa and the impurity 1-chloro-3,3,3-trifluoropropene (R-1233zd) is purified and R-1233zd is removed from the mixture by contacting the mixture with 1-5 mols of chlorine for each mol of R-1233zd in the presence of ultraviolet light having a wavelength between about 300 to 400 nm which provides at least 0.02 watts-hour/kg of the mixture, the R-1233zd being reduced to below 10 wt. ppm or lower, as it is converted to 1,2,2-trichloro-3,3,3-trifluoropropane (R-233) or other propane which contains more chlorine and which has a higher boiling point than R-245fa and can be separated easily from R-245fa, the photochlorination being effected in a manner such that at least about 96 wt. % of the starting amount of R-245fa is maintained in the mixture.

Abstract: This invention is method for preparing a titania bound ion exchange composition comprising admixing crystalline sodium titanate and a hydrolyzable titanium compound and, thereafter drying the titania bound crystalline sodium titanate and subjecting the dried titania bound ion exchange composition to optional compaction and calcination steps to improve the physical strength of the titania bound composition.

Abstract: The present invention provides a process for recovering sulfur hexafluoride ("SF.sub.6 ") from a gas stream using membrane separation.

Abstract: The present invention relates to a process for recovering sulfur hexafluoride ("SF.sub.6 "). More specifically, the invention provides a pressure swing adsorption--desorption process for recovering SF.sub.6 from a gas stream using zeolites, activated carbons, or silicalites to adsorb the SF.sub.6.

Abstract: This invention relates to a photosensitizer which is bound to a titanate polymer, a method of preparing the bound photosensitizer and a process for using the bound photosensitizer. The photosensitizers which may be used in the invention include rose bengal, azure blue, rhodamine B, fluorescein and eosin. The photosensitizer is attached to the titanate by displacing a ligand on the titanate with a hydroxyl group on the photosensitizer. Finally, the bound photosensitizer may be used to oxidize undesirable oxidizable compounds present in a hydrocarbon or aqueous fraction. One specific example is the sweetening of kerosene which involves oxidizing the mercaptans contained in the kerosene to disulfides.