TY - JOUR T1 - Comparison of two sample preconcentration strategies for the sensitivity enhancement of flavonoids found in Chinese herbal medicine in micellar electrokinetic chromatography with UV detection. AU - Zhu,Jinhua, AU - Yu,Kai, AU - Chen,Xingguo, AU - Hu,Zhide, Y1 - 2007/08/12/ PY - 2007/04/19/received PY - 2007/08/02/revised PY - 2007/08/09/accepted PY - 2007/8/29/pubmed PY - 2007/11/1/medline PY - 2007/8/29/entrez SP - 191 EP - 200 JF - Journal of chromatography. A JO - J Chromatogr A VL - 1166 IS - 1-2 N2 - Two on-column preconcentration techniques named stacking with reverse migrating micelles (SRMM) and anion selective electrokinetic injection and a water plug-sweeping with reverse migrating micelles (ASIW-sweep-RMM) were used and compared for concentration and separation of flavonoids in Chinese herbs using reverse migration micellar electrokinetic chromatography (RM-MEKC). The optimal background electrolyte (BGE) used for separation and preconcentration was a solution composed of 20mM phosphoric acid (H(3)PO(4))-100mM sodium dodecyl sulfate (SDS)-20% (v/v) acetonitrile (ACN) buffer (pH 2.0), the applied voltage was -15kV. To achieve reasonable results of the two techniques, the conditions which affected preconcentration were examined. A comparison of used techniques with normal hydrodynamic injection (5s), concerning enhancement factors and limits of detection (LODs) was presented. Under the optimum stacking conditions, about 27-37- and 45-194-fold improvement in the detection sensitivity was obtained for SRMM and ASIW-sweep-RMM, respectively, compared to usual hydrodynamic sample injection (5s). The LODs (S/N=3) for SRMM and ASIW-sweep-RMM in terms of peak height, can reach down to 1.15 x 10(-2) microg/ml for hesperetin and 2.4 x 10(-3) microg/ml for nobiletin, respectively. Finally, the amounts of the six flavonoids in extract of Fructus aurantii Immaturus were successfully determined using ASIW-sweep-RMM. The six analytes were baseline separated with sample matrix under the optimum ASIW-sweep-RMM conditions and the experimental results showed that preconcentration was well achieved after the dilution of sample solutions. SN - 0021-9673 UR - https://www.unboundmedicine.com/medline/citation/17723234/Comparison_of_two_sample_preconcentration_strategies_for_the_sensitivity_enhancement_of_flavonoids_found_in_Chinese_herbal_medicine_in_micellar_electrokinetic_chromatography_with_UV_detection_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S0021-9673(07)01380-5 DB - PRIME DP - Unbound Medicine ER -