By Anonymous on Wednesday, July 3, 2002 - 06:12 am:
Dear chromatographers, please suggest me simple and good method to calculate the peak to valley ratio.
By tom jupille on Wednesday, July 3, 2002 - 11:45 am:
The ratio itself is simple:
hv = perpendicular distance from baseline to valley between two peaks
h2 = perpendicular distance from baseline to the top of the *smaller* of the two peaks
Result is usually expressed as a %:
100 x hv / h2
The question is, what do you want to *do* with the ratio? It can be used to estimate resolution, but the estimates are only approximate because they do not take tailing factors into account.
There is a table relating resolution and valley ratio in the Snyder, Glajch, and Kirkland book "Practical HPLC Method Development, 2nd ed, page 720"
-- Tom Jupille / LC Resources Inc.