Abstract: The technology generally relates to tailoring a back pressure regulator in a chromatographic system to reduce unswept volume within the back pressure regulator to achieve better sample detection and a reduction in chromatographic band distortion effects.

Abstract: The present disclosure discusses a method of separating and/or purifying acidic peptides by the use of a mobile phase having a pH greater than or about equal to the isoelectric point of one or more of the metal oxides in the flow path.

Abstract: The present disclosure pertains to methods of separating nucleic acid component compounds from one another. In some embodiments, the methods comprise: (a) loading a sample fluid comprising a plurality of nucleic acid component compounds onto a chromatographic column comprising a zwitterionic stationary phase contained inside the column; (b) flowing a mobile phase through the chromatographic column over a time period thereby forming an eluent in which at least some of the plurality of the nucleic acid component compounds are separated from each other, the mobile phase comprising a polar aprotic solvent, a protic solvent, and a volatile buffer salt, wherein flowing the mobile phase comprises varying a ratio of the protic solvent to the polar aprotic solvent over at least a portion of the time period and varying an ionic strength of the volatile buffer salt over at least a portion of the time period.

Abstract: Methods for derivatization of biomolecules including glycans or other biopolymers with one or more fluorescent, MS active compounds by reductive amination or rapid tagging in order to produce derivatized glycan having a pKa >7 and between about 200 ? and about 1000 ? of nonpolar surface area are described.

Abstract: Exemplary embodiments are directed to devices for separating a sample by chromatography, components of the devices, and methods for using the devices, and directed to devices and components for use with immobilized enzymatic reactors. A device includes a wall having a wetted surface exposed to a mobile phase including the sample during chromatographic separation. The wetted surface of the wall includes an alloy material including the following constituents: nickel, and cobalt and/or chromium where the alloy is limited in an amount of titanium to 1 wt %. A component includes a body having a wetted surface exposed to a mobile phase including the sample during chromatographic separation. The wetted surface of the body includes an alloy material including the following constituents: nickel, and cobalt and/or chromium where the alloy is limited in an amount of titanium to 1 wt %.

Abstract: Disclosed is a liquid chromatography system and mixer for use therein that includes a first split connected to an inlet, the first split branching the flow of fluid from the inlet into a first path and a second path; a second split connected to an outlet of the first path, the second split branching the first path into a third path and a fourth path; and a third split connected to an outlet of the second path, the third split branching the second path into a fifth path and a sixth path. The first path and the second path are offset by a first predetermined volume, the third path and the fourth path are offset by a second predetermined volume, and the fifth path and the sixth path are also offset by the second predetermined volume.

Abstract: A rotary valve that includes a stator, a rotor and a plurality of sample channels. The stator includes a stator surface having an inlet port, an outlet port and a plurality of selectable ports. The rotor includes a rotor surface having a first rotor channel and a second rotor channel. The rotor is configurable in a plurality of rotor positions, each of which couples the inlet port to one of the selectable ports through the first rotor channel and couples the outlet port to another one of the selectable ports through the second rotor channel. The two selectable ports are coupled to each other through one of the sample channels. The rotor has a bypass state defined by a rotor position, or angular range of rotor positions, at which the inlet port is coupled to the outlet port through the second rotor channel.

Abstract: In some aspects, the present disclosure pertains to chromatographic materials that comprise (a) a bulk material and (b) a zwitterionic polymer covalently linked to a surface of the bulk material, in which the zwitterionic polymer comprises one or more monomer residues that comprise an amide or urea moiety, a positively charged moiety, and a negatively charged moiety. Other aspects of the present disclosure pertain to chromatographic separation devices that comprise such chromatographic materials, to chromatographic methods that employ such chromatographic separation devices, and to kits that contain (i) such chromatographic materials and (ii) one or more chromatographic devices for containing such materials.

Abstract: A diaphragm pressure transducer includes a body having an outer surface and a diaphragm, a strain gauge including a resistive element located on the outer surface, a fluidic inlet, and a fluidic cavity enclosed by the body in fluidic communication with the fluidic inlet, the fluidic cavity having an upper surface. The diaphragm is located between the upper surface of the fluidic cavity and the outer surface of the body. The diaphragm includes a variable thickness across a region defined between the upper surface of the fluidic cavity and the outer surface located below the strain gauge.

Abstract: The exemplary embodiments may provide liquid chromatography systems that are smaller in size and with reduced extra-column volume than conventional liquid chromatography systems. The exemplary embodiments may reduce the size of the liquid chromatography systems enough that the liquid chromatography systems of the exemplary embodiments may be deployed adjacent to automated sample preparation robotics, adjacent to a process stream, or adjacent to the inlet of a mass spectrometer. In addition, the exemplary embodiments may reduce the extra-column volume of the liquid chromatography system by eliminating many of the connection tubes found in conventional liquid chromatography systems and by situating components of the liquid chromatography system in closer proximity.

Abstract: The present invention provides novel chromatographic materials, e.g., for chromatographic separations, processes for its preparation and separations devices containing the chromatographic material; separations devices, chromatographic columns and kits comprising the same; and methods for the preparation thereof. The chromatographic materials of the invention are chromatographic materials comprising having a narrow particle size distribution.

Abstract: 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.

Abstract: Described is a differential scanning calorimeter (DSC) instrument capable of performing analyses of multiple samples at the same time. Some embodiments of DSC instruments described herein include a thermal substrate that provides a substantially uniform temperature across a surface of the substrate. A plurality of DSC units is in thermal communication with the substrate, for example, by mounting the units directly to the surface of the substrate. Each DSC unit includes a second thermal substrate for further thermal isolation, and a reference platform and sample platform to receive a reference cell and a sample cell, respectively. A thermoelectric device is disposed between each platform and the second thermal substrate. Optionally, the reference and sample cells may be disposable chips that can be discarded after measurement are performed, thereby reducing or eliminating the need to clean instrument components to prevent cross-contamination for subsequent instrument operation.

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: The exemplary embodiments control solvent pumps so that system flow is constant. One or more controllers may control the flow rate produced by the pumps over time. The one or more controllers control a first pump so that, as the first pump is refilling, a second pump maintains a sufficient flow rate to compensate for the lost flow due to the refilling event. In some exemplary embodiments, the one or more controllers control the timing of the refilling event for the first event such that the refilling event overlaps with the equilibrating of the chromatography column with solvent(s) from the second pump. Similarly, the one or more controllers control the timing of the refilling event for the second pump such that the refilling event overlaps with the equilibrating of the chromatography column.

Abstract: The present disclosure relates to a method for using chemical tags which have two or more sites for ionization to improve quantification and identification of components of interest from a complex mixture. This method relies on first selectively reacting one or more component in a sample with a chemical tag having two or more sites for ionization, followed by separation of components based on charge status, and finally characterization of each component to identify the same. Additionally disclosed are compounds useful as chemical tags in the disclosed methods.

Abstract: The disclosure relates to a gradient twin column recycling chromatography method that is used to separate a mixture containing closely eluting compounds. In one embodiment, a sample includes a primary organic compound and one or more impurities that closely elute with the primary organic compound. A gradient mobile phase is initially used to remove unwanted early eluting and late eluting impurities from the sample. After the gradient removal of some of the impurities is complete, the remaining mixture of the primary organic compound and the closely eluting impurities are separated using recycle chromatography methodology with an isocratic mobile phase.

Abstract: Reagents comprising MS active, fluorescent molecules with an activated functionality for reaction with amines useful in tagging biomolecules such as N-glycans and uses thereof are taught and described. In particular, compounds for use as a reagent for rapid fluorescence tagging of biomolecules and enhanced MS signaling are provided. The compounds may have optical centers and therefore may occur in different enantiomeric and diastereomeric configurations. These MS active, fluorescent compounds may have three functional components: (a) a tertiary amino group or other MS active atom; (b) a highly fluorescent moiety, and (c) a reactive group that rapidly reacts with amines. The reactive group provides rapid tagging of desired bio-molecules. The fluorescent moiety provides the fluorescent signal. The tertiary amino group provides the MS signal.

Abstract: The present invention provides novel chromatographic materials, e.g., for chromatographic separations, processes for their preparation and separations devices containing the chromatographic materials. The preparation of the inorganic/organic hybrid materials of the invention wherein a surrounding material is condensed on a superficially porous hybrid core material will allow for families of different hybrid packing materials to be prepared from a single core hybrid material. Differences in hydrophobicity, ion-exchange capacity, chemical stability, surface charge or silanol activity of the surrounding material may be used for unique chromatographic separations of small molecules, carbohydrates, antibodies, whole proteins, peptides, and/or DNA.

Abstract: Novel sorbents, devices, kits and methods useful for sample treatment are disclosed herein.