Abstract:
Exemplary embodiments integrate a tee or valve into an outlet end fitting of a liquid chromatography column. The tee or valve is suitable for providing additional fluidic flow paths to ports of the end fitting and eliminates the need for post-column fluidic conduits connecting to tees or valves to insert fluidic inputs or divert flow to outputs. This integration decreases the distance that eluent from the liquid chromatography column has to travel to reach a detector relative to systems that use external tees or valves while providing tee/valve functionality and reducing the fluidic volume post-column. As a result, the exemplary embodiments help decrease sample dispersion.
Abstract:
Described is a reusable fitting for attaching a conduit to a port. The fitting includes a housing, a spring, a retainer and a cap. The retainer is capable of locking and unlocking a conduit in the fitting. The fitting provides a high pressure fluid-tight seal and a substantially zero void volume at the junction of two fluidic conduits. The fitting is removable, reusable and replaceable, and allows a user to make and remake connections of a capillary to a fluidic port without permanently binding a ferrule to a specific capillary and thus to a specific port. The fitting can be replaced if part or all of the fitting is damaged during use.
Abstract:
Described is a tubing assembly which includes a permanently deformable outer tube, an intermediate tube and an inner tube. A radial seal is provided by a uniform radial crimp having a non-zero longitudinal length at a longitudinal location on the tubing assembly. In some embodiments one or both ends of the assembly have a uniform radial crimp and are polished so that the ends of two or more of the tubes are substantially flush with each other to thereby block the passage of fluids between the ends of the tubes. In other embodiments the uniform radial crimps are at other longitudinal locations where a high pressure seal is desired. The longitudinal length and the depth of each uniform radial crimp can be formed to accommodate the requirements of a particular application so that leakage along the tubing assembly is prevented and void volume is reduced or eliminated.
Abstract:
A sprayer assembly for an ion source is disclosed. The sprayer includes a capillary having an outlet, a sheath for the capillary, and an elastic member. The sheath can move relative to the capillary between a first position in which the sheath covers the outlet of the capillary and a second position in which the outlet of the capillary is exposed. When the sheath moves from the first position to or towards the second position, the elastic member provides a restoring force that acts to restore the position of the sheath to or towards the first position.
Abstract:
Techniques and apparatus for thermally controlled interfaces for separation devices and optical flow cell devices with minimized post-column volumes are described. In one embodiment, for example, a column-optical cell assembly may include an insulating device, a chromatography column arranged within the insulating device, and an optical flow cell in fluid communication with the chromatography column, the chromatography column arranged within a minimum distance of the optical flow cell.
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:
The present disclosure relates to methodologies, systems and apparatus for controlling pressure in a CO 2 -based chromatography system. A first CO 2 pump operates in constant flow mode and delivers CO 2 to a chromatography column, and liquid modifier is introduced to the chromatography column according to a gradient. A second CO 2 pump is disposed downstream of the column and operates in constant pressure mode to introduce CO 2 into a flow stream at an output of the column. Liquid modifier is also introduced into the flow stream at the output of the column according to a reverse gradient compared to the gradient entering the chromatography column.
Abstract:
A check valve includes a first valve body having a chamber in which second and third valve bodies are located. The check valve also includes a spring-energized seal disposed in the chamber. The spring-energized seal includes a compliant seal body having an annular shape and a resilient member, such as a cantered spring or O-ring, disposed in a pocket of the seal body. The resilient member applies a force to portions of the seal body to prevent the passage of fluid from a valve inlet port to a valve outlet port unless the differential fluid exceeds the cracking pressure of the check valve.
Abstract:
Methods for transferring a carbon dioxide based separation procedure from a first chromatographic system to a second one are disclosed. An average column pressure for the separation in the first system is identified. A measured average column pressure for the separation in the second system is determined. The measured average column pressure is compared with the identified average column pressure. To more closely match the identified average column pressure, the methods involve one or more of: (a) altering the flow rate of the mobile phase in the second system; (b) altering the composition of the mobile phase in the second system; and/or (c) adding a restrictive element between the inlets of a first column and the detector in the second system.
Abstract:
An apparatus for use in a chromatography system includes a first microfluidic substrate having a first fluidic channel. One end of the first fluidic channel terminates at a first fluidic port on a first side of the first microfluidic substrate and an opposite end of the first fluidic channel terminates at a second fluidic port on a second side of the first microfluidic substrate. A second microfluidic substrate has a second fluidic channel. One end of the second fluidic channel terminates at a first fluidic port on a first side of the second microfluidic substrate. The first side of the second microfluidic substrate abuts the second side of the first microfluidic substrate such that the fluidic port of the second microfluidic substrate aligns with one of the fluidic ports of the first microfluidic substrate and the alignment produces a fluidic path comprised of the first and second fluidic channels.