# What is RRF

I would like to know what is RRF. What are methods to determine it? where can i get literature on it?

Dear Skumar,
RRF-Relative response factor, -a numerical value , which will derive the value of your impurity, when calculated against your main component.
RRF can be derived from slope of linearity curves, obtained for both Impurity and main component.

If the impurity standards are available then make linearity solutions of impurity and the prepare also same concentration solution of active analyte. Then draw straight line and find out linear correlation coefficient, slope, Y-intercept and residual sum of square. Then slop of substance divided by the slope of the impurity and multiply these value by impurity %standard , you will be find RRF value. Those impurities in which no authentic reference material is available and for unknown peaks, the RRF is assumed to be 1.00.

any idea what concentration linearity range to prepare up till?
eg. if my main component has established a linear range of 0.1 - 40ppm, can I just use a range of 1 -5ppm to prepare the impurity concentration range and compare it with the 1 - 5ppm of main component?
how it sounds not confusing.
Thanks
Mike

Can you please explain it by examples it helps a lot. How we can plot the linearity graph.

yep .give example:)