HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY OF METAL-COMPLEXES OF PHEOPHYTIN-A AND PHEOPHYTIN-B

Cu(II), Zn(II), Pb(II), Hg(II), and Ce(IV) complexes of pheophytins a and b were synthesized. The chromatographic retention parameters of ph eophytins a and b, chlorophylls a and b, and the above complexes were determined under conditions of normal-phase and reversed-phase high-pe rformance liquid chromatography (HPLC). The adsorption of metal pheoph ytinates in the hexane-n-butanol (96 : 4)-Silasorb 600 and acetonitril e-ethanol-acetic acid (40 : 40 : 16)-Nucleosil C-18 systems was studie d by HPLC. An interpretation of the arrangement and shape of adsorptio n isotherms is proposed. Factors that affect the chromatographic and a dsorption characteristics of compounds (structural differences between pheophytinates of the a and b series, the nature of the central metal atom, and the nature of the mobile and stationary phases) are discuss ed. It is demonstrated that pheophytins a and b and their metal comple xes can be identified and quantitatively determined by HPLC in the con centration range (0.6-44.0) x 10(-6) M.