HETP

chemistry

Also known as: height equivalent to a theoretical plate, plate height(Show More)

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June 29, 2026

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In chemistry, the height equivalent to a theoretical plate (HETP) is a measure of column efficiency in chromatography. It is defined as the column length divided by the number of theoretical plates (N), or HETP = L/N. A smaller HETP value indicates a more efficient column.1

HETP is influenced by three main processes:
* Molecular diffusion: Solute molecules spreading out, inversely proportional to flow velocity.
* Eddy diffusion: Solute traveling at different rates through the packing material.
* Mass transfer: Slow diffusion between stationary and mobile phases causing peak broadening.2

Understanding these factors helps optimize chromatographic conditions for better separation.2

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chromatography
Column efficiency
…theoretical plate (or plate height), HETP (or h), which is L/N, L being the length of the column. Efficient columns have small h values (see below Plate height).
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…theoretical plate (or plate height), HETP (or h), which is L/N, L being the length of the column. Efficient columns have small h values (see below Plate height).
Read More