Sample application open tubular column

Precolumn derivatization is often inadequate for dirty samples. In these cases, application of a postcolumn reaction detection system will often suffice. Deelder et al. (44) and van der Wal (45) have examined different configurations for postcolumn reactors and defined optimal selections on the basis of reaction time and type and effect on resolution and sensitivity. Both studies preferred the packed-bed reactor to the open tubular reactors when conventional column geometries were employed for separation, that is, 4.6 mm i.d. X 15 or 25 cm. 

Figure 3 Progress of frontal zone under application of pulsed electric field. A pulsed electric field was applied in 2-s cycles (electric field was applied for half of the period, and was stopped for the other half). Frontal zone positions were measured from the digital picture on a CRT. The perpendicular line shows the direction of movement of the frontal zone, and 1 mm in length is equal to 167 pixels. The horizontal line shows the time, and the minimum time scale observed is equal to one-fifteenth. A round open-tubular capillary column 75 pm in diameter and 28 mm in length was used. Applied voltage, 1 50 V. Colored sample methanol solution of 1 mM Rhodamine 6G.

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