1. Electrogenerated chemiluminescence derivatization reagents for carboxylic acids and amines in high-performance liquid chromatography using tris(2,2'-bipyridine)ruthenium(II)
Hirotoshi Morita, Masaharu Konishi Anal Chem. 2002 Apr 1;74(7):1584-9. doi: 10.1021/ac0109669.
2-(2-Aminoethyl)-1-methylpyrrolidine and N-(3-aminopropyl)pyrrolidine (NAPP) were found to be selective and sensitive derivatization reagents for carboxylic acid by high-performance liquid chromatography (HPLC) with electrogenerated chemiluminescence detection using tris(2,2'-bipyridine)ruthenium(II). Free fatty acids and ibuprofen were used as model compounds of carboxylic acids, and the derivatization conditions were optimized with myristic acid as a representative of free fatty acids. All the fatty acids tested were reacted with NAPP to produce highly sensitive derivatives under the mild reaction conditions of room temperature for 30 min in acetonitrile containing 2-bromo-1-ethylpyridinium tetrafluoroborate and 9-methyl-3,4-dihydro-2H-pyrido[1,2-a]pyrimidin-2-one. The chemiluminescence intensities were similar for all fatty acids. The derivatives obtained from 10 free fatty acids were completely separated by reversed-phase chromatography under isocratic elution conditions. The on-column detection limits (signal-to-noise ratio of 3) with proposed HPLC separation and chemiluminescence detection were 70 and 45 fmol for myristic acid and ibuprofen, respectively. The free fatty acids in human plasma were successfully determined using the present method. Histamine, a model compound of primary amines, was also determined after precolumn derivatization with 3-(diethylamino)propionic acid at room temperature for 60 min in acetonitrile containing N,N'-dicyclohexylcarbodiimide and 3,4-dihydro-3-hydroxy-4-oxo-1,2,3-benzotriazine with the detection limit of 70 fmol.
2. Electrogenerated chemiluminescence derivatization reagent, 3-isobutyl-9,10-dimethoxy-1,3,4,6,7,11b-hexahydro-2H-pyrido[2,1-a]isoquinolin-2-ylamine, for carboxylic acid in high-performance liquid chromatography using tris(2,2'-bipyridine)ruthenium(II)
Hirotoshi Morita, Masaharu Konishi Anal Chem. 2003 Feb 15;75(4):940-6. doi: 10.1021/ac020377i.
3-Isobutyl-9,10-dimethoxy-1,3,4,6,7,11b-hexahydro-2H-pyrido[2,1-a]isoquinolin-2-ylamine (IDHPIA) was found to be a selective and highly sensitive derivatization reagent for carboxylic acid by high-performance liquid chromatography (HPLC) with electrogenerated chemiluminescence detection using tris(2,2'-bipyridine)ruthenium(II). Free fatty acids and phenylbutylic acid were used as model compounds of carboxylic acids, and the derivatization conditions were optimized with myristic acid. Under the mild reaction conditions of room temperature for 45 min in acetonitrile containing 2-bromo-1-ethylpyridinium tetrafluoroborate and 9-methyl-3,4-dihydro-2H-pyridol1,2-a]pyrimidin-2-one, all the fatty acids tested were reacted with IDHPIA to produce highly sensitive derivatives. The chemiluminescence intensity was essentially the same for all fatty acids. The derivatives obtained from 10 free fatty acids were completely separated by reversed-phase chromatography under isocratic elution conditions. The on-column detection limit (signal-to-noise ratio of 3) with proposed HPLC separation and chemiluminescence detection was 0.5 and 0.6 fmol for myristic acid and phenylbutylic acid, respectively. IDHPIA was 100-fold more sensitive than previously developed reagents (Morita, H.; Konishi, M. AnaL Chem. 2002, 74, 1584-1589). The free fatty acids in human serum were successfully determined using the present method.
