Abstract:
A significant reduction in extra-column band broadening can be achieved by decoupling the injection system from the main solvent flow line. Systems and methods for such decoupling can allow for the injection of larger volumes of sample without compromising separation yield, increase the column loading per batch, and increase the overall yield of separations. For example, a mixture of co-solvent and sample can be prepared separately from the main flow of mobile phase and co-solvent (e.g., a mixture of CO 2 and methanol), loaded onto an injection loop, and then injected directly into the main flow of mobile phase and co-solvent before the chromatography column.
Abstract:
The present disclosure relates to a sensitive, multidimensional chromatography method for extraction, detection, and quantification of non-conjugated cytotoxic agents and associated linker molecules used in cysteine based antibody-drug-conjugate production.
Abstract:
The present disclosure relates generally to methods and apparatus for determining essential nutrients and the ratio of essential nutrients in a sample. In particular, the present disclosure relates to the use of surface desorption ionization-mass spectrometry methods and apparatus to assay essential nutrients and ratios thereof, e.g., omega-6/omega-3 ratios.
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 rotary valve used in chromatography includes a stator with a plurality of stator ports arranged on the stator. The stator further includes a stator groove connected at one end to a first stator port and terminating between the first stator port and a second stator port adjacent to the first stator port. A rotor, rotatably fitted to the stator, has a plurality of arcuate channels arranged in an asymmetrical pattern on the rotor. Each rotor channel connects to one or more of the stator ports. Different connections of the rotor channels to the stator ports produce at least three different positions for the injection valve. The three different positions provide a complete chromatography sample injection sequence using only a single valve.
Abstract:
A method of mass spectrometry comprises ionising a sample and obtaining mass spectral data relating to a plurality of ion detection events. The method then comprises applying match tolerances for mass to charge ratio (m/z), chromatographic retention time (t r ), and ion mobility drift time (t d ), to the ion detection events in order to determine possible charge state connections. The method also comprises constructing a tentative isotope chain and querying ion detection events for a match to the tentative isotope chain. Once a tentative isotope chain has been constructed, the method further comprises determining a corresponding theoretical molecular mass and a corresponding theoretical isotopic distribution, querying one or more lookup tables and returning one or more parameters (New X, New X', Δ New X') related to the fractional mass to charge ratio (f m/z ) and at least one of: ion mobility drift time (t d ); and nominal mass to charge ratio (N m/Z ), of the ion detection events, and using the one or more parameters (New X, New X', Δ New X') to determine a unique charge state of the ions.
Abstract:
A passive pre-heater assembly includes a thermally conductive heat-spreading block and a plurality of passive pre-heaters in thermally conductive communication with the heat-spreading block. The plurality of the pre-heaters exchanges heat with the thermally conductive heat-spreading block. Each pre-heater includes a thermally conductive base in thermal communication with the heat-spreading block, and a plurality of thermally conductive fins is in thermal communication with the thermally conductive base. The plurality of fins of each pre-heater exchanges heat convectively with ambient air and conductively with the thermally conductive base of that pre-heater. A given one of the passive pre-heaters further comprises a tube in thermally conductive contact with the thermally conductive base of the given passive pre-heater. The thermally conductive heat-spreading block exchanges heat with a fluid passing through the tube of the given passive pre-heater.
Abstract:
A column-conditioning enclosure includes a column chamber adapted to hold one or more chromatography separation columns. A duct system provides an airflow path around the column chamber such that the one or more chromatography separation columns held within the column chamber are isolated from the airflow path. An air mover disposed in the airflow path generates a flow of air within the duct system. A heat exchanger system disposed in the airflow path near the air to exchange heat with the air as the air flows past the heat exchanger system. The air circulates through the duct system around the column chamber, convectively exchanging heat with the column chamber to produce a thermally conditioned environment for the one or more chromatography separation columns held within the column chamber.
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.
Abstract:
The present disclosure relates to an apparatus for regulating the average mobile phase density or pressure in a carbon dioxide based separation system. The apparatus includes a controller, a set of pressure or density sensors and a set of instructions capable of determining the pressure drop across a column and adjusting at least one system component or parameter to achieve a pre-determined average mobile phase density or pressure in the system.