title: Determination of berberine by measuring the enhanced total internal reflected fluorescence at water/tetrachloromethane interface in the presence of sodium dodecyl benzene sulfonate.
abstract: A highly sensitive method for determination of berberine is proposed based on the measurements of total internal reflected fluorescence (TIRF) at water/ tetrachloromethane (H(2)O/CCl(4)) interface. In the pH range of 2.6-5.7, the co-adsorption of the berberine with the anionic surfactants such as sodium dodecyl benzene sulfonate (SDBS), sodium dodecylsulfonate (SDS), and sodium lauryl sulfate (SLS) occurs at the H(2)O/CCl(4 )interface, resulting in greatly enhanced TIRF signal characterized by the emission at 526 nm when excited with a 351 nm light beam. The enhanced TIRF intensity is in proportion to the berberine concentration in the range 0.2-10.0x10(-7) mol L(-1). The limit of detection is 1.7x10(-9) mol L(-1) (3sigma). It was found that ions such as Ca(II), Cu(II), Fe(III), Cd(II), Mg(II), Zn(II), Pb(II), and Al(III) can be allowed larger than 1.0x10(-4) mol L(-1). Meanwhile, the organic compounds such as vitamin B, saccharine, and amino acid do not display any effect for the present TIRF method even if they are larger than 1.0x10(-2) mol L(-1)in high concentration levels (larger than 1.0x10(-5) mol L(-1)). The results of determination for synthetic samples were agreement with the desired values, and the ones for tablets were identical with those obtained according to the method of Chinese Pharmacopoeia.
authors.affiliation: Institute of Environmental Chemistry, College of Chemistry and Chemical Engineering, Southwest Normal University, 400715, Chongqing, P. R. China.
authors.forename: Ping
authors.initials: P
authors.lastname: Feng
authors.forename: Cheng Zhi
authors.initials: CZ
authors.lastname: Huang
authors.forename: Yuan Fang
authors.initials: YF
authors.lastname: Li
mesh_terms: D000596:Amino Acids / Q000737:chemistry; D001557:Benzenesulfonates / Q000737:chemistry*; D001599:Berberine / Q000032:analysis* / Q000737:chemistry*; D002138:Calibration; D002251:Carbon Tetrachloride / Q000737:chemistry*; D005453:Fluorescence; D012015:Reference Standards; D012680:Sensitivity and Specificity; D014867:Water / Q000737:chemistry*
chemical_list: D000596:Amino Acids; D001557:Benzenesulfonates; D014867:Water; D001599:Berberine; C001114:dodecylbenzenesulfonic acid; D002251:Carbon Tetrachloride