HPLC separation of heterocyclic β-diketonates of actinide, lanthanide and transition metals

Detection of metal ions by liquid chromatographic separation of their 1,3-dimethyl-4-acetyl-2-pyrazolin-5-one chelates

“…The early elution of the broad thorium peak is probably due to the hydrolysis of thorium. Morales and Bartholdi also reported hydrolysis of thorium PMBP complexes (16). Several other metal-DMAP peaks were also observed in other chromatograms.…”

“…Upon addition of DMAP to the eluent, metal-complex peaks were seen. Other groups have reported that the addition of complexing agent to the eluent improved peak shape (7,8,16). Varying the concentration of DMAP in the eluent did not affect the peak retention times, but the peaks were broader at lower DMAP concentrations.…”

“…Morales and Bartholdi separated 1 Present address: National Bureau of Standards, Gaithersburg, MD 20899. 0003-2700/88/0360-2244$01.50/0 uranium(VI), iron(III), thorium(IV), copper(II), zirconium(IV), and neptunium(IV) complexes of I-phenyl-3-methyl-4benzoyl-2-pyrazolin-5-one (PMBP) by using a C-18 column and an acetonitrile-water eluent (16). A high percentage of organic modifier was required (>90%) because the complexes are very hydrophobic and are insoluble in water.…”

Determination of Uranium by Packed-Column Supercritical Fluid Chromatography with 1-Phenyl-3-methyl-4-benzoylpyrazolin-5-one

“…In papers dealing with the separation by HPLC of metal chelates in the presence of HPMBP, acetonitrile was employed as mobile phase. − This solvent was therefore tested here as a polar modifier instead of methanol. Compared with methanol, a degradation of the HPMBP elution peak was observed.…”