On2line Enrichment of Neutral Solute in Capillary

    Electrochromatography

    Zhang Weibing , Zhu Jun , You Jinmao , Zhang Bo , Ping Guichen , Zhang Yukui

    3

    ( National Chromatographic Research Analysis Center , Dalian Institute of

    Chemical Physics , Chinese Academy of Sciences , Dalin 116011)

    Abstract On2line enrichment of neutral solute in capillary electrochromatography (CEC) can be achieved by

    varying the concentration of organic modifier in sample solution and running buffer , together with extending the

    injection time. On2line enrichment is mainly controlled by two processes : self2enrichment and transfer enrichment .

    Based on the method of relaxation theory , an expression , which described the relationship between enrichment factor

    and running condition , was theoretically derived. Due to this expression , higher enrichment factor can be obtained ......