Abstract: Lycium barbarum L., a kind of traditional Chinese herb, is found to have bioactivities such as anticancer, antioxidant, hypoglycemic and immunological activities. In both in vitro and in vivo studies, the carotenoids were found to be a class of the effective compounds. The carotenoids in Lycium barbarum L. were separated by high performance liquid chromatography with diode array detection (HPLC-DAD). Seven peaks were obtained by HPLC on a C18 column with acetonitrile-methylene chloride (60∶40, v/v) as mobile phase at a flow-rate of 1.0 mL/min. Most of the peaks that had been validated as single peaks in the 2-dimensional chromatography were found to be overlapping peaks. The overlapping chromatographic peaks were resolved by chemometric methodHeuristic Evolving Latent Projection (HELP) based on 3-dimensional data. As an example, the chromatogram and UV spectra of 4 isomers were obtained by resolving an overlapping peak. These results showed that the combination of chemometric methods and modern analytical instruments provides an effective method for the analysis of complex systems such as isomers.

Key words: isomer, Heuristic Evolving Latent Projection, Lycium barbarum L. , carotenoids, high performance liquid chromatography-diode array detection