Quantitation of chromatographic peaks in the 0.1 to 1.0% range

Abstract

Quantitation by peak area or height has been investigated for small peaks which are accompanied by a large neighbour of 100 or 1000 times greater size. The peaks were generated by a computer and evaluated with an integrator. The parameters varied were peak order, relative peak width, tailing, and resolution. First eluted small peaks were evaluated by vertical drop; for last eluted small peaks vertical drop and tangent skimming methods were compared. It was found that the size of small peaks can be determined accurately if they precede the large one and if their height is used for quantitation. Under these conditions even poor resolution and tailing can be tolerated. However, if the peaks are truly Gaussian, the elution order is of minor importance. If the small peak is eluted after the large one the only recommendation is to achieve true baseline resolution if possible. The quantitation of narrow “rider” peaks is problematical. The results are not only presented in tabulated form but representative peak pairs are also shown as an aid for the analyst. A real liquid chromatographic separation confirms the results.