A gas chromatography guard column assembly is disclosed including a guard column having an inlet and an outlet. The guard column is disposed in a coil having a column coil aspect ratio of less than 15. A gas chromatography system is disclosed including an oven cavity, a heater assembly, an inlet, a guard column, an analytical column, and a detector. The guard column is in fluid communication with the inlet and is disposed in a guard column coil. The analytical column is in fluid communication with the guard column and is disposed in an analytical column coil. The detector is in fluid communication with the analytical column. The analytical column coil has an analytical column coil central axis aligned with a central axis of the heater assembly, and the guard column coil has a guard column coil central axis remote from the central axis of the heater assembly.

A ratchet fitting includes a screw portion and an operating portion. One of the screw portion and the operating portion has an engaging member, and the other one of the screw portion and the operating portion has an elastic member and a holding member formed separately from the elastic member. The elastic member and the engaging member are fitted such that a rotational force is transmittable to each other due to engagement of the projection and the protrusion and engagement between the projection and the protrusion is releasable due to deformation of the elastic member. The elastic member has a first fitting portion, the holding member has a second fitting portion, and the holding member and the elastic member are fitted such that the first fitting portion and the second fitting portion are fitted to each other in a rotation direction.

The disclosed system and method improve measurement of trace volatile chemicals, such as by Gas Chromatography (GC) and Gas Chromatography/Mass Spectrometry (GCMS). A first trapping system can include a plurality of capillary columns in series and a focusing column fluidly coupled to a first detector. The first trapping system can retain and separate compounds in a sample, including C3 hydrocarbons and compounds heavier than C3 hydrocarbons (e.g., up to C12 hydrocarbons, or compounds having a boiling point around 250° C.), and can transfer the compounds from the focusing column to the first detector. A second trapping system can receive compounds that the first trapping system does not retain, and can include a packed trap and two columns. The second trapping system can remove water from the sample and can separate and detect compounds including C2 hydrocarbons and Formaldehyde.

A ratchet fitting includes a screw portion and an operating portion. One of the screw portion and the operating portion has an engaging member, and the other one of the screw portion and the operating portion has an elastic member and a holding member formed separately from the elastic member. The elastic member and the engaging member are fitted such that a rotational force is transmittable to each other due to engagement of the projection and the protrusion and engagement between the projection and the protrusion is releasable due to deformation of the elastic member. The elastic member has a first fitting portion, the holding member has a second fitting portion, and the holding member and the elastic member are fitted such that the first fitting portion and the second fitting portion are fitted to each other in a rotation direction.

A parallel assembly of chromatography column modules, the assembly having one common assembly inlet and one common assembly outlet, each column module comprising a bed space filled with chromatography medium and each column module comprises integrated fluid conduits which when the column module is connected with other column modules are adapted to connect the bed space of the column module with the assembly inlet and the assembly outlet, wherein the total length and/or volume of the fluid conduit from the assembly inlet to one bed space together with the length and/or volume of the fluid conduit from the same bed space to the assembly outlet is substantially the same for all bed spaces and modules installed in the parallel assembly.

A parallel assembly of chromatography column modules, the assembly having one common assembly inlet and one common assembly outlet, each column module comprising a bed space filled with chromatography medium and each column module comprises integrated fluid conduits which when the column module is connected with other column modules are adapted to connect the bed space of the column module with the assembly inlet and the assembly outlet, wherein the total length and/or volume of the fluid conduit from the assembly inlet to one bed space together with the length and/or volume of the fluid conduit from the same bed space to the assembly outlet is substantially the same for all bed spaces and modules installed in the parallel assembly.

A compression fitting includes a nut with a threaded end for receiving a threaded tube and a receiving end for holding a plunger head; and a plunger with an inner bore for receiving a capillary tube and the plunger head for engaging a ferrule positioned within the receiving end between the plunger head and the threaded tube, the plunger slidingly engaged with the nut to force the ferrule from the nut.

A method of making Lu-177 involving dissolving enriched Yb.sub.2O.sub.3, loading dissolved enriched Yb.sub.2O.sub.3 on a first guard column containing resin prepared from (2-ethyl-1-hexyl)phosphonic acid mono(2-ethyl-1-hexyl)ester (HEH[EHP]), passing a first separation of a stream exiting from first guard column through a first resin cartridge containing dipentyl pentylphosphonate, collecting Lu-177 onto a first collection column having resin containing tetraoctyl diglycolamide (DGA), loading an exiting stream from first collection column on a second guard column containing resin prepared from (2-ethyl-1-hexyl)phosphonic acid mono(2-ethyl-1-hexyl)ester (HEH[EHP]); passing a first separation of a stream exiting from second guard column through a second resin cartridge containing dipentyl pentylphosphonate; collecting Lu-177 onto a second collection column having resin containing DGA; passing a second separation of a stream exiting from second guard column through a third resin cartridge containing dipentyl pentylphosphonate; and collecting Lu-177 having passed through the third resin cartridge onto a third collection column having resin containing DGA.

A system for analyzing a gas mixture, including at least one chromatography column, a mechanism injecting the mixture into the column, and a mechanism detecting compound(s) forming the gas mixture, the detection mechanism including at least one detector of nanosensor type of an outlet of the column and a detector of nanosensor type in the column, capable of detecting passage of the compounds. It is then possible to determine the velocity of each of the compounds within the system.

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.