(21)
If peak heights are employed instead of peak areas,
(22)
where (Hp) is the peak height of component (p) in the sample,
and (Hst) is the peak height of the standard in the sample.
If the response index (r) is not close to unity, the value of (r) should be taken into account in the expressions used to obtain quantitative results. Consider the computer integration of the area. The area is calculated by summing all the signals from the detector over the period of the peak. Now, if (r ?1) then the area that will incorporate the non-linearity will be
where (a(r)) is the corrected area of the peak for a non-linear detector
with a response index of (r),
and (V) is the detector output
The areas, provided by normal data acquisition and processing software, will not give this corrected area without program modification.
Thus, equation (17) must be modified to
(23)
equation (18) must be modified to
(24)
Equation (19) employs peak heights and thus peak height values taken as those provided by the computer but must be raised to the (r) th root; thus,
(25)
and equation (20) becomes
(26)
A weighed amount of standard is added to the sample and the sample is chromatographed. Let the concentration of the standard be (Cst), the concentration of any component (p) be (Cp) and the peak areas corrected for the response index (r) of the component (p) and that of the standard (Ap(r)), (Ast(r)) respectively; then
(27)
If peak heights are employed instead of peak areas,
(28)
Thus, the concentration of any (or all) of the components present in the mixture can be determined, assuming they are all adequately separated from one another. If the computer program has not been written to accommodate detector response factors, either peak heights must be used or the chromatogram must be processed manually.
