A method for determining moment values of elution peaks measured by means of high-performance liquid chromatography or capillary electrophoresis.

Abstract

Moment analysis of first absolute (µ_1A) and second central (µ_2C) moments of elution peaks measured by using high-performance liquid chromatography or capillary electrophoresis is effective for extracting the information about chemical phenomena relating to their separation behavior from equilibrium and kinetic points of view. It is known that elution peak profiles should be integrated to obtain more accurate values of µ_1A and µ_2C. This means that it is required to appropriately determine the range for integrating the elution peak profiles. Our research group has used a method for determining the start and end points of the integration range. However, it seems that signal noise, baseline drift, and peak asymmetry affects the selection of the integration range and the accuracy in the determination of µ_1A and µ_2C values of elution peaks. Simulated elution peaks were prepared by adding signal noise of different intensities to a base Gaussian peak and by changing the slope of baseline. Asymmetrical peaks, i.e., tailing and leading, were also prepared by using the Exponentially Modified Gaussian function while changing the degree of asymmetry. The method was applied to choose the start and end points for integrating the simulated elution peaks. Then, the values of µ_1A and µ_2C were calculated by integrating the simulated elution peak profiles in the integration range. It was tried to clarify how the magnitude of signal noise, baseline drift, and peak asymmetry affect the selection of the integration range of elution peaks and the determination of their µ_1A and µ_2C values.