Resolution of overlapping capillary electrophoresis peaks by using chemometric analysis: Improved quantification by using internal standard

Discussed in this paper is the application of internal standard for quantification of compounds in overlapping peaks from capillary electrophoresis diode array detection, which has not often been studied. A strategy is proposed to calculate the calibration coefficient in this case. The resolution of overlapping capillary electrophoresis peaks is achieved by using second order multivariate curve resolution method. Before resolution, the signals are baseline-corrected by automation baseline correction, in which a smoothed signal is used for both baseline recognition and modeling. An evolving routine is used to determine the peak shift and improve the repeatability of migration times. The quantification results are compared with those of generalized rank annihilation method. For multivariate curve resolution method, improved quantification precision results from using internal standard, but further research is expected in the case of generalized rank annihilation method.