Number of theoretical plates per column (USP)

Tangent method (USP, ASTM):

where
t_R	Retention time
W_t	Tangent width [min]

Half-width method (ASTM, EP, JP; USP 2022):

where
t_R	Retention time
W_50	Peak width at half-height [min]

See Also

• Pharmacopeia values in OpenLab CDS
• NOTE: Retention time used for performance tests