Peak Purity and Identification Variable:
Relative Standard Deviation of the Peak Ratio Value (RSD Peak Ratio)

The RSD Peak Ratio column indicates the relative standard deviation of the peak ratio mean value. (Also, see Integration  Peak Ratio.)

To determine the relative standard deviation, the mean value is formed for all ratio values (PPI avg) of a peak. Then the (Q-sum) square sum is calculated.

The standard deviation (SD) is defined as the root of the square sum (Q-Sum) divided by (n-1), where n is the number of data points.

The relative standard deviation of the ratio value (RSD (RATIO)) in percent results when the standard deviation is divided by the peak ratio mean value (PPI avg) and is then multiplied by 100%.