Column tube configuration

Extra-column volumes for typical HPLC and UHPLC systems are listed in Table 3.1, with the extra-column volume for a UHPLC being about 4.5 times lower than that for an HPLC. It should be pointed out that experimentally determined extra-column volumes are typically somewhat higher than those calculated in Table 3.1 due to the parabolic flow profile of the mobile phase in the connection tubing. The experimental value of extra-column volume is dependent on mobile phase viscosity, flow rate, mobile phase composition, tubing configuration, etc. (32,33). 

HdC separation also occurs in the interstices of a packed column, although the configuration of channels is not as simple as a microcapillary tube. The... 

Ensure that the actual instrument configuration conforms to what is written under Experimental supplier, models, modifications, consumables (HPLC or GC columns, gaskets, etc.), and software for the main instrument, peripherals (injectors, integrators, computers, printers, plotters, etc.), and ancillary equipment (vortexer, dispensers, balances, centrifuges, filters, tubing, etc.). 

Porous alumina tube externally coated with a MgO/PbO dense film (in double pipe configuration), tube thickness 2.5 mm, outer diameter 4 mm, mean pore diameter 50 nm, active film-coated length 30 mm. Feed enters the reactor at shell side, oxygen at tube side. Oxidative methane coupling, PbO/MgO catalyst in thin film form (see previous column). r-750X,Pr ed 1 bar. Conversion of methane <2%. Selectivity to Cj products > 97%. Omata et al. (1989). The methane conversion is not given. Reported results are calculated from permeability data. 

If these are packed in a square configuration with a negligible tube wall thickness, each tube occupies an area 1 cm in the tube bundle. The cross-sectional area of the tube bundle is 590 cm so the diameter of the column is... 

A replaceable C disk electrode (two-electrode system) was used for end-column amperometric detection of biogenic amines. The electrode was inserted through a guide tube and was 30 5 [tm away from the capillary exit. This configuration allowed easy replacement of the electrode, especially after biofouling. The electrode was situated at a central position to maximize coulombic... 

In an article on drift tubes of comparatively large size and a cylindrical geometry [54], Buryakov and Kolomiets combined a multi-capillary column [55,56] with the analyzer to obtain measurements and quantitative response curves with a GC-DMS configuration. 

The stationary phase can be a liquid or a solid. If it is a liquid, it can be coated directly on the inside walls of a capillary tube (column), or it can be coated on an inert solid support and be handled like a solid. In effect, then, there are three stationary phase configurations in the first type, a solid (with or without stationary liquid) is packed into a column in the second type, a solid is coated on the surface of a flat, plane material like glass (TLC), and in the third type, a liquid is coated on the inside wall of an open tube (OT). 

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