title: Studies on the effects of imidazole on the peroxyoxalate chemiluminescence detection system for high performance liquid chromatography.
abstract: The catalytic effect of bases (imidazole, pyridine, Tris and triethylamine) on the peroxyoxalate chemiluminescence (PO-CL) reaction for high performance liquid chromatography (HPLC) was investigated. Imidazole increased PO-CL intensity extraordinarily, whereas the other bases (pyridine, Tris and triethylamine) did not. The peak heights of dipyridamole (coronary vasodilator) obtained using the eluents containing buffers were largest at pH 7.0, a few times less at pH 6.0 and pH 5.0, 100 times less at pH 4.0 and a few hundred times less at pH 3.0. The eluents containing buffers at pH 3, 4, 5, 6 or 7 each with imidazole increased the peak heights by a few to ten times as compared with those without imidazole, and those peak heights were within one order of magnitude. On the other hand, the eluent containing buffer at pH 2 did not affect the peak heights with or without imidazole. Bis(4-nitro-2-(3,6,9-trioxadecyloxycarbonyl)phenyl) oxalate (TDPO) alone and bis(2,4-dinitrophenyl)oxalate (DNPO) plus TDPO were recommended to be used against eluents containing buffers of pH 5-7 and pH 3-4, respectively. Dipyridamole and benzydamine hydrochloride (anti-inflammatory drug) were separated on the ODS column and detected by the present system. The detection limits of dipyridamole and benzydamine hydrochloride were 40 amol and 270 fmol, respectively.
authors.affiliation: Branch Hospital Pharmacy, University of Tokyo, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Imai
authors.forename: A
authors.initials: A
authors.lastname: Nishitani
authors.forename: Y
authors.initials: Y
authors.lastname: Tsukamoto
authors.forename: W H
authors.initials: WH
authors.lastname: Wang
authors.forename: S
authors.initials: S
authors.lastname: Kanda
authors.forename: K
authors.initials: K
authors.lastname: Hayakawa
authors.forename: M
authors.initials: M
authors.lastname: Miyazaki
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D007093:Imidazoles / Q000494:pharmacology*; D008163:Luminescent Measurements; D010070:Oxalates / Q000032:analysis / Q000378:metabolism*
chemical_list: D007093:Imidazoles; D010070:Oxalates; C044622:peroxyoxalate