Abstract: Described is a method for determining a dwell volume of a liquid chromatography system and a liquid chromatography system that can determined the system dwell volume. The method includes mixing a flow of a first solvent with a flow of a second solvent to form a solvent mixture. The flows of the first and second solvents are decreased and increased, respectively, to generate a gradient composition. A system pressure of the liquid chromatography system is measured to determine a pressure trace defined as the measured system pressure as a function of time. The dwell volume of the system is determined from a time delay determined between the gradient composition at the mixing location and the pressure trace. The method can be performed with a liquid chromatography system having a chromatographic column or a flow restrictor used in place of the chromatographic column.

Abstract: The present disclosure relates to techniques for detecting leaks in a pump. A compressed fluid, such as compressed CO2, is provided through a first channel formed within a pump head. The compressed fluid within the first channel is in contact with at least a portion of a pump piston, and the first channel is substantially sealed using a fluid seal positioned around a portion of the pump piston. A wash fluid is pumped into a second channel formed within a wash seal housing associated with the pump head using a fluid pump. The wash fluid within the second channel surrounds a portion of the pump piston and is separated from the first channel by the fluid seal. A flow rate of fluid exiting the wash seal housing via the second channel is measured, and the existence of a leak is determined based on the measured flow rate.

Abstract: Exemplary embodiments eliminate the need for column ovens in serial column chromatography arrangements and systems by using insulated sleeves. The insulated sleeves may encase individual chromatography columns or clusters of chromatography columns. The use of the insulated sleeves allows the chromatography columns to be positioned in close proximity to each other. This may decrease the overall size of a serial column chromatography arrangement and may reduce costs by not requiring the column ovens.

Abstract: The exemplary embodiments may provide a collective insulating sleeve for a plurality of chromatography columns or may provide separate insulating sleeve for each of the chromatography columns in a plurality. As a result, column ovens are not needed, and pre-heaters may not be required for each chromatography column in some exemplary embodiments. Thus, parallel column arrangements in the exemplary embodiments may be more compact than conventional arrangements.

Abstract: In one aspect, the present invention provides a chromatographic stationary phase material for various different modes of chromatography represented by Formula 1: [X](W)a(Q)b(T)c (Formula 1). X can be a high purity chromatographic core composition having a surface comprising a silica core material, metal oxide core material, an inorganic-organic hybrid material or a group of block copolymers thereof. W can be absent and/or can include hydrogen and/or can include a hydroxyl on the surface of X. Q can be a functional group that minimizes retention variation over time (drift) under chromatographic conditions utilizing low water concentrations. T can include one or more hydrophilic, polar, ionizable, and/or charged functional groups that chromatographically interact with the analyte. Additionally, b and c can be positive numbers, with the ratio 0.05?(b/c)?100, and a?0.

Abstract: The exemplary embodiments may determine a temperature set point for an outlet heater or cooler based on available information without requiring user input or requiring only minimal user input. The exemplary embodiments may estimate the temperature set point of the outlet heater based on available information, such as pressure delta along the column, temperature at the inlet of the chromatography column, and volumetric flow rate. In some instances, the estimate may be normalized for column dimensions, such as length and diameter. Tailing factor may also be used in determining the estimate. The estimate is not computationally burdensome and can be recalculated as the chromatography column is in use.

Abstract: Described are methods and fluidic networks for injecting a sample into a liquid chromatography system. The method may be applied for separations in which increased sensitivity is desired and a large sample volume in a strong solvent is to be injected. The method may include merging a flow of a solvent having a sample dissolved therein with a flow of a diluent. The merging occurs in a fluidic path to an injection valve. The full amount of sample previously contained in a smaller volume of solvent is maintained in a larger volume of a diluted sample that includes the strong solvent and the diluent. The entire volume of the diluted sample is loaded into a sample loop coupled to the injection valve and subsequently injected into the system flow of the chromatography system.

Abstract: In one aspect, the present invention provides a chromatographic stationary phase material for various different modes of chromatography represented by Formula 1: [X](W)a(Q)b(T)c (Formula 1). X can be a high purity chromatographic core composition having a surface comprising a silica core material, metal oxide core material, an inorganic-organic hybrid material or a group of block copolymers thereof. W can be absent and/or can include hydrogen and/or can include a hydroxyl on the surface of X. Q can be a functional group that minimizes retention variation over time (drift) under chromatographic conditions utilizing low water concentrations. T can include one or more hydrophilic, polar, ionizable, and/or charged functional groups that chromatographically interact with the analyte. Additionally, b and c can be positive numbers, with the ratio 0.05?(b/c)?100, and a?0.

Abstract: Methods for transferring a separation procedure from a first chromatographic system to a second one are disclosed that involve substantially matching a pressure profile. In some such methods, a length, an area, and a particle size of a first column in the first system and a flow rate in the first separation procedure are identifiable. Some such methods also involve selecting a combination of a length, an area, and a particle size of a second column in the second system and a flow rate for the second separation procedure. These methods may involve calculating a target length, a target area, or a target particle size for the second column in the second system or a target flow rate for the second separation procedure.

Abstract: Described herein are a selectable flow restriction device and a fluidic network for chromatographic sample dilution during injection. A selectable flow restriction device is used in combination with a splitter to define an adjustable splitter for separating a high-pressure solvent flow into two separate solvent flows having the same solvent composition. The first solvent flow passes to a sample manager where a sample is injected as a discrete fluidic plug at an injection valve into a flow comprising at least one solvent. The second solvent flow is merged downstream from the location of injection with the first solvent carrying the sample fluidic plug. The second solvent flow dilutes the sample plug during the mixture of the two solvent flows.

Abstract: Methods for transferring a carbon dioxide based separation procedure from a reference chromatographic system to a target chromatographic system involve alternative techniques for determining system pressure drops not attributable to the column. One technique involves leveraging experimental chromatography to develop a correction factor that is a function of at least one correction coefficient and at least one ratio of the differential analyte retention time to the retention time in the reference system. Another technique involves leveraging other experimental measurements of tubing pressure drops under various condition to develop a lookup table that can be used to identify likely tubing pressure drops in the target system. A third technique leverages knowledge of the separation procedure and the target system and the likely nature of the relevant flow to calculate tubing pressure drops in the target system.

Abstract: Described is a method for determining a dwell volume of a liquid chromatography system and a liquid chromatography system that can determined the system dwell volume. The method includes mixing a flow of a first solvent with a flow of a second solvent to form a solvent mixture. The flows of the first and second solvents are decreased and increased, respectively, to generate a gradient composition. A system pressure of the liquid chromatography system is measured to determine a pressure trace defined as the measured system pressure as a function of time. The dwell volume of the system is determined from a time delay determined between the gradient composition at the mixing location and the pressure trace. The method can be performed with a liquid chromatography system having a chromatographic column or a flow restrictor used in place of the chromatographic column.

Abstract: 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.

Abstract: 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.

Abstract: Methods for transferring a carbon dioxide based separation procedure from a first chromatographic system to a second one involve identifying an average column pressure for the separation in the first system is identified, determining a measured average column pressure for the separation in the second system, and comparing the measured average column pressure with the identified average column pressures. To more closely match the identified average column pressure, the methods involve: (a) altering a cross-sectional area of a column packed with media in the second system; and/or (b) adding makeup fluid along the length of the column in the second system. Columns with the characteristics used in the methods and second chromatographic systems are disclosed.

Abstract: The present disclosure relates to techniques for detecting leaks in a pump. A compressed fluid, such as compressed CO2, is provided through a first channel formed within a pump head. The compressed fluid within the first channel is in contact with at least a portion of a pump piston, and the first channel is substantially sealed using a fluid seal positioned around a portion of the pump piston. A wash fluid is pumped into a second channel formed within a wash seal housing associated with the pump head using a fluid pump. The wash fluid within the second channel surrounds a portion of the pump piston and is separated from the first channel by the fluid seal. A flow rate of fluid exiting the wash seal housing via the second channel is measured, and the existence of a leak is determined based on the measured flow rate.

Abstract: Described are stator arrays for multi-valve systems used in different chromatographic applications. Also described is a mounting assembly for a multi-valve system that includes the stator array. Each stator array has a stator body having a first stator surface and a second stator surface. Each stator surface has a plurality of stator ports and is configured to engage a rotor surface of a rotary valve actuator. A fluid channel inside the stator body couples one of the stator ports of the first stator surface to one of the stator ports of the second stator surface. The fluid channel may be a microfluidic channel. A solid-state diffusion bonding process in which two or more parallel layers of material are joined together may be used to fabricate the stator body. Complex fluid channel networks may be formed using many fluid channels formed in multiple layers within the stator body.

Abstract: In one aspect, the present invention provides a chromatographic stationary phase material for various different modes of chromatography represented by Formula 1: [X](W)a(Q)b(T)c (Formula 1). X can be a high purity chromatographic core composition having a surface comprising a silica core material, metal oxide core material, an inorganic-organic hybrid material or a group of block copolymers thereof. W can be absent and/or can include hydrogen and/or can include a hydroxyl on the surface of X. Q can be a functional group that minimizes retention variation over time (drift) under chromatographic conditions utilizing low water concentrations. T can include one or more hydrophilic, polar, ionizable, and/or charged functional groups that chromatographically interact with the analyte. Additionally, b and c can be positive numbers, with the ratio 0.05?(b/c)?100, and a?0.

Abstract: An adjustment tool for a multiport valve including an elongate frame having a fitted end with an exit aperture, a pressure chamber in fluidic communication with the exit aperture, the fitting end sealingly couplable with the multiport valve to form sealed fluidic communication between the multiport valve and the pressure chamber through the exit aperture, a pressure valve actuable to open and close fluid flow from the pressure chamber to outside the frame, a bore. An elongate stabbing body is slidable and rotatable within the bore and having an adjustment end, the elongate stabbing body slidable within the bore from a first unactuated configuration where the adjustment end and is contained within the pressure chamber through the exit aperture to a second projected configuration wherein the adjustment end is extended outside the elongate frame and into the multiport valve when the fitted end is coupled with the multiport valve.

Abstract: In one aspect, the present invention provides a chromatographic stationary phase material for various different modes of chromatography represented by Formula 1: [X](W)a(Q)b(T)c (Formula 1). X can be a high purity chromatographic core composition having a surface comprising a silica core material, metal oxide core material, an inorganic-organic hybrid material or a group of block copolymers thereof. W can be absent and/or can include hydrogen and/or can include a hydroxyl on the surface of X. Q can be a functional group that minimizes retention variation over time (drift) under chromatographic conditions utilizing low water concentrations. T can include one or more hydrophilic, polar, ionizable, and/or charged functional groups that chromatographically interact with the analyte. Additionally, b and c can be positive numbers, with the ratio 0.05?(b/c)?100, and a?0.