#Usp resolution calculator how to#

How much larger depends on the disparity in the peak sizes and on the details of the tailing peak shape. If the first peak tails, then the overlap between the two peaks will be larger than it would be if both were Gaussian. Once you get away from Gaussian peaks, things become hazy. As the resolution decreases, of course, this approach becomes less accurate. If the two peaks are moderately well separated, you can characterize the first peak by the front half of it's width (i.e., the distance from the leading edge of the peak to it's 'centerline') and the second peak by the back half of its width. The simplest answer to your question is: if the peaks are reasonably Gaussian, then sigma can be obtained from a peak width measurement made at any fraction of the peak height all you need is a table of the normal distribution (or a copy of Excel). The traditional measure of Rs = 1.5 as '99% baseline resolution' comes from the the fact that it represents a 6-sigma separation between peak centers, and thus has just under 1% overlap between two equal-sized Gaussian peaks. Width at half-height is 2.35 * sigma, etc. Baseline width (where the tangents intersect the baseline) is 4 * sigma. The distribution of a Gaussian can be characterized by it's variance (sigma-squared) and thus by sigma. (kind of important) the peaks are comparable in size (at least within the same order of magnitude). (less important) the peaks are already reasonably well separated.ģ. (very important) the peaks are GaussianĢ. That is a large, economy-sized can of worms.įirst of all, the usual definition of resolution is built on three assumptions:ġ. Sorry for the lack of introduction and stuff in this my first post but i have to get revising!!! Would i have to do the same type of calculation for this or can i just plug the numbers in as they are.AND do i solve the brackets first then times by 5.54 then square it or square it first then times by 5.54 I THINK i have to convert everything to seconds by measuring the baseline and seeing what 1cm equates to in terms of time e.g 1cm = 60secs of chromatogram, and measuring the PW in cm and multiplying this by the value in time of one cm and then solving.am i right? Also the same question goes for calculating plates

#Usp resolution calculator how to#

I am revising basic hplc principles in readiness for a job interview tomorrow and for the life of me cannot remember how to manually calculate the resolution factor.I know the equation isīut i seem to remember from calculating these years ago that it is not just a case of putting in the RT in min and the PW in cm. I stumbled onto this site while trying to find the answer to my following question and hope somebody here could help me