Abstract: Methods for focusing analyte peaks in liquid chromatography using a spatial temperature gradient are provided. Also provided are methods for focusing analyte peaks and improving resolution using a trap column upstream of a separation column. Further, methods are provided in which the trap column placed upstream of the separation column is packed with a temperature-sensitive polymer/copolymer, and a spatial temperature gradient is applied along the trap column for obtaining improved retentivity by trap column stationary phase, and overall improved resolution of analyte peaks.

Abstract: Exemplary embodiments are directed to methods and systems for controlling fluid parameters within a detector. A first and second fluid pump manager control the flow of a first and second fluid to one or more heating/cooling devices, and a mixer receives and mixes the first and second fluids. An optical detector flow cell receives the fluid mixture from the mixer, and a pressure regulator controls the pressure at the optical detector flow cell. Thus, the composition, temperature, and pressure of a fluid mixture entering an optical detector flow cell can be controlled in real time.

Abstract: A system that incorporates teachings of the subject disclosure may include, for example, a process that includes obtaining a porous medium comprising a porous material having a first shape and an initial porosity profile. The porous medium is engaged with a cavity in a fluidic device, wherein the cavity is in fluid communication with a channel of the fluidic device. The first shape of the porous material can be adjusted to a second shape resulting in the initial porosity profile being adjusted to a target porosity profile. Such adjustment can be accomplished by the engaging of the porous medium with the cavity, by pre-adjusting a shape of the porous media before insertion into the cavity, or by some combination thereof. Other embodiments are disclosed.

Abstract: Described are a method and apparatus for diluting a chromatographic sample. The method includes repeating an alternating acquisition of sample fluidic plugs each having an incremental volume of sample and diluent fluidic plugs each having an incremental volume of diluent to obtain a stack of alternating sample and diluent fluidic plugs. The stack is inserted into a flow of a mobile phase in a chromatography system. Alternatively, the method includes repeating the steps of injecting an incremental volume of sample into a chromatographic system flow and providing an incremental volume of mobile phase into the chromatographic system flow. In either implementation, the dilution ratio of the sample equals the sum of the incremental volumes of the sample and the diluent or mobile phase divided by the sum of the incremental volumes of the sample.

Abstract: A liquid chromatography system including a solvent delivery pump for delivering a mobile phase through the liquid chromatography system, an injector for injecting a sample into the mobile phase, a column for effecting a separation of components of the sample, and a dispersive element positioned between the injector and the column, the dispersive element configured to dilute a sample solvent in the mobile phase prior to entering the column is provided. Further dispersive elements, systems, and methods are also provided.

Abstract: A method for injecting a diluted sample in a chromatography system includes merging a flow of a sample and a flow of a diluent to form a flow of a diluted sample. A dilution ratio of the diluted sample equals a sum of the volumetric flow rates of the sample and the diluent divided by the volumetric flow rate of the sample. The diluted sample is stored in a holding element before injection into a chromatographic system flow. Sample dilution occurs under low pressure relative to the chromatographic flow thereby allowing lower pressure sample and diluent syringes to be used. Other benefits include reduced compressibility and a reduction in leaks due to the lower pressure operation. The method avoids problems associated with manual techniques which can introduce errors due, for example, to loss of sample, sample precipitation and adsorption of sample to vials.

Abstract: Methods for focusing analyte peaks in liquid chromatography using a spatial temperature gradient are provided. Also provided are methods for focusing analyte peaks and improving resolution using a trap column upstream of a separation column. Further, methods are provided in which the trap column placed upstream of the separation column is packed with a temperature-sensitive polymer/copolymer, and a spatial temperature gradient is applied along the trap column for obtaining improved retentivity by trap column stationary phase, and overall improved resolution of analyte peaks.

Abstract: A method of performing a chromatographic separation includes generating a spatial temperature gradient along a length of a chromatographic column in a liquid chromatography system. A sample is injected into a flow of a mobile phase to the column and a flow of a mobile phase having a composition gradient is provided to the column after the sample is received at the column. The spatial temperature gradient is moved along the length of the column from the column inlet to the column outlet during the time that the composition gradient traverses the column. This coordination of the composition gradient with the movement of the spatial thermal gradient yields a significant increase in peak capacity per unit time compared with conventional separation techniques performed in a conventional isothermal column environment.

Abstract: A system that incorporates teachings of the subject disclosure may include, for example, a process that includes obtaining a porous medium comprising a porous material having a first shape and an initial porosity profile. The porous medium is engaged with a cavity in a fluidic device, wherein the cavity is in fluid communication with a channel of the fluidic device. The first shape of the porous material can be adjusted to a second shape resulting in the initial porosity profile being adjusted to a target porosity profile. Such adjustment can be accomplished by the engaging of the porous medium with the cavity, by pre-adjusting a shape of the porous media before insertion into the cavity, or by some combination thereof. Other embodiments are disclosed.

Abstract: Provided are systems and methods for adapting to volume variations in microfluidic chromatography columns. A column is calibrated by comparing a parameter of the column with a same parameter of a reference column and generating, by a processor, an adjustment factor in response to the comparison between the parameter of the column with a same parameter of the reference column. Volume differences between the calibrated column and the reference column are compensated for by integrating the generated adjustment factor into a sample separation involving the calibrated column.

Abstract: Described are a chromatographic separation device and a method for performing a chromatographic separation. The device two chromatographic separation modules in serial communication. The first module is adapted to receive a gradient includes mobile phase. The second module receives the gradient mobile phase that exits from the first module. The first and second modules include chromatographic sorbents that differ in one or more of composition, particle size and sorbent temperature. The retentivity of the second module is greater than the retentivity of the first module and the chromatographic dispersion of the second module is less than the chromatographic dispersion of the first module. The width of a chromatographic peak eluted from the first module is greater than a width of the same chromatographic peak after elution from the second module. The device has a high peak capacity without the need to pack a full column length with small sorbent particles.

Abstract: A system that incorporates teachings of the subject disclosure may include, for example, a process that includes obtaining a porous medium comprising a porous material having a first shape and an initial porosity profile. The porous medium is engaged with a cavity in a fluidic device, wherein the cavity is in fluid communication with a channel of the fluidic device. The first shape of the porous material can be adjusted to a second shape resulting in the initial porosity profile being adjusted to a target porosity profile. Such adjustment can be accomplished by the engaging of the porous medium with the cavity, by pre-adjusting a shape of the porous media before insertion into the cavity, or by some combination thereof. Other embodiments are disclosed.

Abstract: The present invention provides methods for enhancing chemical reactions of molecules, e.g., biomolecules, with destructible surfactants. The chemical reactions may involve and/or be associate with analysis, e.g., solubilizing, separating, purifying and/or characterizing the molecules. In one aspect, the anionic surfactants of the present invention may be selectively broken up at relatively low pH. The resulting breakdown products of the surfactants may be removed from the molecule/sample with relative ease. The invention has applicability in a variety of analytical techniques.

Abstract: Provided are systems and methods for adapting to volume variations in microfluidic chromatography columns. A column is calibrated by comparing a parameter of the column with a same parameter of a reference column and generating, by a processor, an adjustment factor in response to the comparison between the parameter of the column with a same parameter of the reference column. Volume differences between the calibrated column and the reference column are compensated for by integrating the generated adjustment factor into a sample separation involving the calibrated column.

Abstract: A system that incorporates teachings of the subject disclosure may include, for example, a process that includes obtaining a porous medium comprising a porous material having a first shape and an initial porosity profile. The porous medium is engaged with a cavity in a fluidic device, wherein the cavity is in fluid communication with a channel of the fluidic device. The first shape of the porous material can be adjusted to a second shape resulting in the initial porosity profile being adjusted to a target porosity profile. Such adjustment can be accomplished by the engaging of the porous medium with the cavity, by pre-adjusting a shape of the porous media before insertion into the cavity, or by some combination thereof. Other embodiments are disclosed.

Abstract: Embodiments of the present invention are directed to articles of manufacture, devices, methods and apparatus for performing liquid chromatography featuring a chromatographic sorbent having one or more pentafluorophenyl groups, wherein said one or more pentafluorophenyl groups are a bonded phase on a sorbent selected from the group comprising silica, organic polymers or hybrid organic silane material and said pentafluorophenyl groups are in a mono-, bi-, and tridentate forms.

Abstract: Embodiments of the present invention are directed to articles of manufacture, devices, methods and apparatus for performing liquid chromatography featuring a chromatographic sorbent having one or more pentafluorophenyl groups, wherein said one or more pentafluorophenyl groups are a bonded phase on a sorbent selected from the group comprising silica, organic polymers or hybrid organic silane material and said pentafluorophenyl groups are in a mono-, bi-, and tridentate forms.

Abstract: The present disclosure relates to the use of aptamers in solid phase extraction, chromatography and chromatography-mass spectrometry systems. More specifically, the present disclosure relates to the use of aptamers in SPE and chromatography systems to selectively retain, extract and/or pre-concentrate target molecule(s) having a specific affinity for the particular aptamer(s). The target molecule(s) can be further analyzed by mass spectrometry with limited interferences and/or enhanced sensitivity.

Abstract: The present invention provides methods for enhancing chemical reactions of molecules, e.g., biomolecules, with destructible surfactants. The chemical reactions may involve and/or be associate with analysis, e.g., solubilizing, separating, purifying and/or characterizing the molecules. In one aspect, the anionic surfactants of the present invention may be selectively broken up at relatively low pH. The resulting breakdown products of the surfactants may be removed from the molecule/sample with relative ease. The invention has applicability in a variety of analytical techniques.

Abstract: The present invention provides methods for enhancing chemical reactions of molecules, e.g., biomolecules, with destructible surfactants. The chemical reactions may involve and/or be associate with analysis, e.g., solubilizing, separating, purifying and/or characterizing the molecules. In one aspect, the anionic surfactants of the present invention may be selectively broken up at relatively low pH. The resulting breakdown products of the surfactants may be removed from the molecule/sample with relative ease. The invention has applicability in a variety of analytical techniques.