Height equivalent to a theoretical plate HEPT

Van Deemter equation An equation relating efficiency (HEPT in mm) to linear flow velocity in a chromatographic column. The efficiency is expressed as the height equivalent to a theoretical plate HEPT = A + BIV + Cv), where A, B, and Cv are constants and V is the linear velocity of the carrier gas. This equation tells us that to obtain maximum efficiency, the carrier gas flow must be optimized. 

Efficiency Degree of band broadening for a given retention time. It is expressed as the number of theoretical plates, N, or as the height equivalent to a theoretical plate, HEPT. 

The flow of gas through the column and the diffusion of the solute in both gas and liquid all influence the solute band-width and, hence, efficiency and resolution. Early in the history of GC it was shown (by van Deemter and coworkers for packed columns, and by Golay for capillary columns) that H, height equivalent to a theoretical plate (HEPT) depends on the average linear gas velocity (u) through the column according to Equation 13.1 ... 

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See also in sourсe #XX -- [ , , ]

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