HETP vs sample size

At present, gas chromatographic analysis of impurities is an important area of gas chromatography because great importance attaches to trace analysis in many practical activities [17, 43-45]. 

A quantitative study was performed on the relationship between the height equivalent to a theoretical plate (HETP or H) values and the sample size (W). Such a general equation has been proposed elsewhere [67]. Earlier it appeared to be in good agreement with the experimental data for open capillary columns with a stationary liquid phase layer (absorbent) and for packed capillary columns [69]. 

The dependence of column efficiency on sample size for capillary column with aluminum oxide layer on its inner walls has been studied by Berezkin and Volkov [26]. The initial experimental data were processed by the following equation  

Fused-silica column (Chrompack, the Netherlands), 50 m x 0.32 mm with aluminum oxide, column temperature 100 °C, flame ionization detector, analyte n-butane. 

Interestingly, the Hq value is virtually the same irrespective of sample injection technique (split or splitless). This characteristic is an additional test of equation (3-21). 

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