Reduced, chromatogram plate height

The basic parameters employed in the analysis of the CPC chromatograms are the retention volume V which is related to the stationary phase and mobile phase volumes V, and V , respectively, and the distribution ratio of the analyte D [Eq. (1)], the chromatographic efficiency, as measured by the number of theoretical plates N, which is calculated from the retention volume V, and the width of the chromatogram w, [Eq. (2)], the chromatographic inefficiency represented by the channel equivalent of a theoretical plate (CETP), which is analogous to reduced plate height and is the ratio of the number of channels (CH) (2400 in our experiments) to N [Eq. (3)], and the selectivity I achieved in the separation of two analytes (1 and 2), which is the ratio of their distribution ratios A and D2 [Eq. (4) [2] ... 

Comparison was made between the radial measurements and that made with a bulk detector, a commercial amperometrlc detector. When the Individual radial measurements were weighted and summed as described earlier, the reconstructed chromatogram superimposed on that measured with the bulk detector. Separation efficiencies measured in the center of the column were at least 20% higher than those measured with the bulk detector. Host notable was the very high efficiency obtained with uric acid (k - 0.33) where a reduced plate height of 1.5 was obtained at a flow rate of 0.56 mL mln. This represents a 90% Improvement over the separation efficiency obtained with the bulk detector. 

The emission of the indicator is reduced in places where there are substance zones that absorb at 2 = 254 nm present in the chromatogram. This produces dark zones (Fig 4A), whose intensity (or rather lack of it) is dependent on the amount of substance applied. If the plate background is set to 100% emission the phosphorescence is reduced appropriately in the region of the substance zones. When the chromatogram is scanned peaks are produced, whose position with respect to the start can be used to calculate Rf values and whose area or height can be used to construct cahbration curves as a function of the amount applied (Fig. 25). 

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