Normalized interpolated peak height

Fig. 26. Normalized interpolated peak height of 731 cm 1 absorption vs. temperature. Maximum error of measurement is 3 % (within data marker)...

In order to minimize the possibility of errors as a result of variable injection volumes, the internal standard (IS) method should be used. It involves the addition of a compound, the IS, which is not already present in the sample. This is normally a substance that elutes at a position near the sample component of interest and should be well resolved and readily detected under the given chromatographic conditions. The IS is added in constant amount to solutions that contain varying amounts of the analytical standard. Calibration curves are then constructed by plotting the ratio of either the areas or peak heights of the two peaks (analyte/IS) versus amount or concentration of analyte. The amount or concentration of each chromatographed sample can then be obtained by interpolation of the calibration curve. The calibration plot should be a straight line with an intercept of zero. However, non-linear standard curves may result when... 

Figure 6. Normalized peak heights of 731 cm absorption vs. temperature for raw data and interpolated data of slow-crystallized sample. Maximum error of...

Good results can be obtained by using a more direct iterative method which can be briefly presented n equidistant values are chosen on the elution volume scale let us note these values as V, (typically, n can be 200). Any sample is arbitrarily defined as the sum of n isomolecular species, whose positions at the peak apex are Vj. For each peak /, n values of heights for each Vi value are computed, normalizing the surface (the peak shape is defined by interpolation from experimental BB data). 

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