Provided is a supercritical fluid chromatography method, system, and components comprising such a system wherein a non-polar solvent may replace a portion or all of a polar solvent for the purpose of separating or extracting desired sample molecules from a combined sample/solvent stream. The method and system are designed to eliminate or reduce the amount of polar solvent necessary for chromatographic separation and/or extraction of desired samples to less than or equal to twenty percent polar solvent within the total volume concentration of the total solvents used, and the technique may include one or more of a supercritical fluid chiller, a supercritical fluid pressure-equalizing vessel, and a supercritical fluid cyclonic separator. The supercritical fluid chiller and the use of the chiller allow efficient and consistent pumping of liquid-phase gases employing off-the-shelf HPLC pumps in the supercritical chromatography system using liquid-phase gas mobile phase. The pressure equalizing vessel allows the use of off the shelf HPLC column cartridges in the supercritical chromatography system. The cyclonic separator efficiently and effectively allows for separation of sample molecules from a liquid phase or gas phase stream of a supercritical fluid. The technique may further incorporate the use of one or more disposable cartridges containing silica gel or other suitable medium for use as a chromatographic separation column. The technique may also utilize an open loop cooling circuit using fluids with a positive Joule-Thompson coefficient.

In embodiments, a packing material for supported liquid extraction has a sorbent media that includes synthetic silica particles. In embodiments, the synthetic silica particles can have physical properties relating to one or more of particle surface area, shape, size, or porosity. In one embodiment, synthetic silica particles have a surface area less than about 30 m.sup.2/g. In another embodiment, the synthetic silica particles have an approximately uniform particle shape. In further examples, synthetic silica particles have a particle size in a range of about 30-150 m inclusive or greater than about 200 m. In another embodiment, synthetic silica particles are arranged to have a pore size greater than about 500 Angstroms. In an embodiment, an apparatus for supported liquid extraction includes a container and a sorbent media that includes synthetic silica particles. In a further embodiment, a method for extracting target analytes through supported liquid extraction is provided.

In embodiments, a packing material for supported liquid extraction has a sorbent media that includes synthetic silica particles. In embodiments, the synthetic silica particles can have physical properties relating to one or more of particle surface area, shape, size, or porosity. In one embodiment, synthetic silica particles have a surface area less than about 30 m.sup.2/g. In another embodiment, the synthetic silica particles have an approximately uniform particle shape. In further examples, synthetic silica particles have a particle size in a range of about 30-150 m inclusive or greater than about 200 m. In another embodiment, synthetic silica particles are arranged to have a pore size greater than about 500 Angstroms. In an embodiment, an apparatus for supported liquid extraction includes a container and a sorbent media that includes synthetic silica particles. In a further embodiment, a method for extracting target analytes through supported liquid extraction is provided.

The present disclosure relates to the determination of analytes in a sample using chromatography. The present disclosure provides methods of separating an analyte from a sample. A mobile phase is flowed through a chromatography column. The mobile phase includes about 0.005% (v/v) to about 2.50% (v/v) difluoroacetic acid and less than about 100 ppb of any individual impurity, especially metal impurities. A sample including the analyte is injected into the mobile phase. The analyte is separated from the sample.

The present disclosure relates to the determination of analytes in a sample using chromatography. The present disclosure provides methods of separating an analyte from a sample. A mobile phase is flowed through a chromatography column. The mobile phase includes about 0.005% (v/v) to about 2.50% (v/v) difluoroacetic acid and less than about 100 ppb of any individual impurity, especially metal impurities. A sample including the analyte is injected into the mobile phase. The analyte is separated from the sample.

Certain embodiments described herein are directed to systems and methods that can be used to analyze species in a fluid stream. In some configurations, a sorbent tube effective to directly sample aromatics and/or polyaromatics in a fluid stream is described.

The present disclosure relates to a method of separating a compound of interest, particularly unsaturated compound(s) of interest, from a mixture. The compound is separated using a column having a chromatographic stationary phase material for various different modes of chromatography containing a first substituent and a second substituent. The first substituent minimizes compound retention variation over time under chromatographic conditions. The second substituent chromatographically and selectively retains the compound by incorporating one or more aromatic, polyaromatic, heterocyclic aromatic, or polyheterocyclic aromatic hydrocarbon groups, each group being optionally substituted with an aliphatic group. In some examples, the present disclosure can include a chromatographic system having a chromatographic column having a stationary phase with a chromatographic substrate containing silica, metal oxide, an inorganic-organic hybrid material, a group of block copolymers, or a combination thereof.

The present disclosure relates to a method of separating a compound of interest, particularly unsaturated compound(s) of interest, from a mixture. The compound is separated using a column having a chromatographic stationary phase material for various different modes of chromatography containing a first substituent and a second substituent. The first substituent minimizes compound retention variation over time under chromatographic conditions. The second substituent chromatographically and selectively retains the compound by incorporating one or more aromatic, polyaromatic, heterocyclic aromatic, or polyheterocyclic aromatic hydrocarbon groups, each group being optionally substituted with an aliphatic group. In some examples, the present disclosure can include a chromatographic system having a chromatographic column having a stationary phase with a chromatographic substrate containing silica, metal oxide, an inorganic-organic hybrid material, a group of block copolymers, or a combination thereof.

The present invention relates to a flow-through device comprising at least one separation column wherein a first packing component, which comprises particles of alumina and/or silica, and a second packing component, which comprises a powder of one or more hygroscopic salts are provided. The two packing components may be blended or layered in the device, which may comprise a single tube or a plurality of tubes arranged in a plate format, such as the wells of a multiwall plate or tubes in a rack. In addition, the invention relates to a method for removing one or more matrix components, such as pigments, from a biological sample, by passing said sample across a first packing component, which comprises particles of alumina and/or silica, and a second packing component, which comprises a powder of one or more hygroscopic salts.

A silica monolith nested in a polymer sponge may be formed by applying a hydrolyzed mixture of siloxanes to a melamine-formaldehyde sponge, and may be used in methods of solid phase extraction.