Determination of lipoic acid and dihydrolipoic acid in human plasma and urine by high-performance liquid chromatography with fluorimetric detection.
J Chromatogr A
; 870(1-2): 381-8, 2000 Feb 18.
Article
in En
| MEDLINE
| ID: mdl-10722093
ABSTRACT
A highly sensitive method for the determination of alpha-lipoic acid (LA) and dihydrolipoic acid (DHLA) in human plasma and urine has been developed. Samples were acidified and extracted with organic solvent, and the free sulfhydryls of DHLA protected as the dicarboxyethylate by treatment with ethylchloroformate. The free carboxylic function of LA and the SH-protected DHLA were converted into their amide derivatives with the strong fluorophore 2-(4-aminophenyl)-6-methylbenzothiazole in the presence of a coupling agent and a base catalyst. The resulting fluorescent amides of both LA and DHLA were separated on a reversed-phase column (Ultrasphere C8) using simple isocratic elution with acetonitrile-water (8020) and detected fluorimetrically (excitation 343, emission 423 nm). The method is highly sensitive, reproducible, and is easily applied for the simultaneous determination of LA and DHLA in biological samples.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Chromatography, High Pressure Liquid
/
Thioctic Acid
Type of study:
Diagnostic_studies
Limits:
Humans
Language:
En
Journal:
J Chromatogr A
Year:
2000
Document type:
Article