Determination of erythromycin A in rat plasma and urine by high-performance liquid chromatography with chemiluminescence detection using Tris(2,2'-bipyridine)ruthenium(II).

A simple and sensitive method was developed for the determination of erythromycin A (EA), decladinosyl erythromycin A (dClEA) and erythromycin B (EB) in rat plasma and urine by high-performance liquid chromatography with electrogenerated chemiluminescence detection using Tris(2,2'-bipyridine)ruthenium(II). The recovery rates of EA, dClEA and EB were 97, 94 and 85% from rat plasma and 89, 83 and 93% from rat urine, respectively. The calibration curves were linear over the concentration ranges 0.

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).

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.

Electrogenerated chemiluminescence derivatization reagents for carboxylic acids and amines in high-performance liquid chromatography using tris(2,2'-bipyridine)ruthenium(II).

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.

Evaluation and application of liquid chromatographic columns coated with 'intelligent' ligands. II. Phospholipid column.

The stationary phases of octadecylsilica (ODS) coated with phospholipid have been developed as a model of artificial lipid membranes for liquid chromatographic columns. An ODS column coated with phospholipid can be readily prepared by recycling a solution containing L-alpha-dipalmitoyl-phosphatidylcholine (DPPC) through an ODS column in a closed loop. DPPC becomes absorbed on the ODS surfaces by hydrophobic interaction between the acyl group of DPPC and the octadecyl group of the ODS surfaces.