Technical data

Understanding Your Agilent ChemStation 249
Evaluating System Suitability
11
Performance Test Definitions
Resolution (USP, ASTM) R
(Pertaining to peaks a and b, T
R
of peak a < T
R
of peak b; T
R
in min)
Tangent method (USP, ASTM):
5 Sigma method:
Half-width method (Resolution used in Performance Report):
Statistical method:
where:
M1
(x)
= mean retention time for peak x (1st Statistical Moment) [min]
W
B(x)
= base width for peak x [min]
W
4.4(x)
= width at 4.4% height for peak x [min]
W
50(x)
= width at 50% height for peak x [min]
W
S
(x) = width derived from statistical moments = for peak x [min] (see
also “Statistical Moments” on page 244)