A crescent PLOT column is disclosed, including a capillary column having an inlet, an outlet, a bore, and an inner surface surrounding the bore and extending between the inlet and the outlet. A layer of particles is localized on a radial portion of the inner surface. The layer of the particles includes a radial thickness decreasing from a center of the radial portion to a periphery of the radial portion, forming a crescent shape in a radial frame of reference. A method for preparing the crescent PLOT column is disclosed, including loading the capillary column with a fluid including a carrier and particles such that the fluid is contained within the capillary column. The capillary column and the fluid contained within the capillary column are subjected to a centrifugal force. The carrier is removed, and a layer of the particles is localized on the radial portion of the inner surface.

Open tubular capillary columns for liquid and ion chromatography, based upon an ionically impermeable polyolefin capillary having a bore with a sulfonate-group- or amine-group-functionalized internal surface. The capillary columns may include a coating of ion exchanging nanoparticles electrostatically bound to the functionalized internal surface. The capillary columns may be made by exposing the interior surface to a sulfonating reagent comprising chlorosulfonic acid (CISO.sub.3H), preferably from 85 wt % to 95 wt % chlorosulfonic acid at a process temperature of 20 to 25 C. The interior surface may be subsequently exposed to an asymmetrical diamine to form a sulfonic mid-linkage to the diamine, i.e., to form a sulfonamide-linked, amine-group-functionalized internal surface. The coating may be provided by subsequently exposing the interior surface to an aqueous suspension of ion exchanging nanoparticles to electrostatically bond the ion exchanging nanoparticles to the functionalized internal surface.

The invention provides metal liquid chromatography components with uniformly coated internal surfaces and methods for achieving the same. The invention addresses the problem of corrosion or interference of metal components in the flow path for LC analyses in which the sample interacts with metal ions or surfaces. The invention also alleviates the difficulties in coating very long metal tubes and very small metal channels with an inert, continuous coating that adheres well to metal surfaces. The metal flow path is rendered inert by the coating, and thus compatible with bioanalytical separations, for example, by using a vapor phase deposition process to coat the inner surfaces with a coating that continuously covers all metal surfaces in the flow path.

Liquid chromatography techniques are disclosed. Specifically, the liquid chromatography technique includes providing a liquid chromatography system having a coated metallic fluid-contacting element, and transporting a fluid to contact the coated metallic fluid-contacting element. Conditions for the transporting of the fluid are selected from the group consisting of the temperature of the fluid being greater than 150 C., pressure urging the fluid being greater than 60 MPa, the fluid having a protein-containing analyte incompatible with one or both of titanium and polyether ether ketone, the fluid having a chelating agent incompatible with the one or both of the titanium or the polyether ether ketone, and combinations thereof.

Presented herein is a new concept of uniformly spin coating a flat surface with a stationary phase and creating a gas chromatography column by pressing a grooved lid, with micro-stamped ridges, down onto the coated substrate. The lids are molded out of commercially available rigid materials including epoxies so that when pressed onto a flat surface it will create an air tight seal. The epoxy material is rendered inert by a thin layer of gold.

Open tubular capillary columns for liquid and ion chromatography, based upon an ionically impermeable polyolefin capillary having a bore with a sulfonate-group- or amine-group-functionalized internal surface. The capillary columns may include a coating of ion exchanging nanoparticles electrostatically bound to the functionalized internal surface. The capillary columns may be made by exposing the interior surface to a sulfonating reagent comprising chlorosulfonic acid (ClSO.sub.3H), preferably from 85 wt % to 95 wt % chlorosulfonic acid at a process temperature of 20 to 25 C. The interior surface may be subsequently exposed to an asymmetrical diamine to form a sulfonic mid-linkage to the diamine, i.e., to form a sulfonamide-linked, amine-group-functionalized internal surface. The coating may be provided by subsequently exposing the interior surface to an aqueous suspension of ion exchanging nanoparticles to electrostatically bond the ion exchanging nanoparticles to the functionalized internal surface.

Method for exchanging materials, wherein a gaseous, liquid or supercritical mobile phase containing species to be separated is circulated through a packing comprising a stationary phase, the method being characterised in that:the packing comprises a plurality of capillary ducts formed in at least one first material, the ducts passing through the packing between an upstream face through which the mobile phase enters the packing and a downstream face through which the mobile phase leaves the packing,each duct comprises, on at least one portion of the inner wall thereof, at least one secondary material consisting of an organic gel or porous mineral,the thickness of the secondary material defines, inside the duct, at least one empty tubular channel of solid material, the channel being open so as to allow the mobile phase to enter and extending continuously between the upstream and downstream faces of the capillary ductthe secondary material has a thickness between 0.05 times and 0.5 times the diameter of the channelthe method is carried out with a velocity of the mobile phase between 5.0 times and 50 times the speed of the optimum mobile phase defined by the minimum of the Van Deemter curve of the majority separating compound under the method conditionsthe cumulative volume of the capillary ducts is more than 15% of the total packing volume.

Liquid chromatography and gas chromatography components with a conformal protective coating on internal surfaces thereof and methods for producing the same are provided. The conformal protective coating is formed via an atomic layer deposition (ALD) process. The components and methods of the present disclosure find use in providing protective coatings for liquid chromatography and gas chromatography components that are compatible with bioanalytical separations and sensitive trace analyses.

The present disclosure relates to a filter. The filter includes a porous element, a compression element and a housing. At least a portion of the porous element is coated with an alkylsilyl coating. The compression element is configured to receive the porous element thereby forming an assembly. The housing has an opening formed therein. The opening is configured to receive the assembly. The assembly is retained within the opening when the assembly is received therein.

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. The method includes introducing a sample comprising the analytes into a chromatographic system. The chromatographic system has a flow path disposed in an interior of the chromatographic system, at least a portion of the flow path having an active coating, and a chromatographic column having a stationary phase material in an interior of the chromatographic column that facilitates separation of the analytes in the sample through interaction with at least one analyte in the sample. The active coating is selected to interact with at least one analyte in the sample through (1) a repulsive force, (2) a secondary interaction, or (3) a retention mechanism distinct from the interaction with the stationary phase material.