A sensitive liquid chromatographic method for the analysis of isovaleric and valeric acids in urine as fluorescent derivatives.
A simple and sensitive isocratic liquid chromatographic method was developed for the analysis of isovaleric and valeric acids in human urine as biomarkers in metabolic acidosis. The method is based on the derivatization of isovaleric and valeric acids with a fluorescent reagent 2-(2-naphthoxy)ethyl-2-(piperidino)ethanesulfonate for labeling the analytes with the naphthoxy fluorophore. The resulting fluorescent derivatives of isovaleric and valeric acids were separated on a phenyl-hexyl column, using a mixed solvent of methanol-water-tetrahydrofuran (55:31:14, v/v) as the mobile phase. The separated derivatives were monitored with a fluorimetric detector (excitation at 225 nm and emission at 360 nm). The linear range of the method for the determination of isovaleric acid or valeric acid derivative was over 0.2 approximately 8.0 microM. The detection limit (signal to noise ratio=3 with 10 microl injected) of isovaleric acid or valeric acid was about 0.04 microM. Application of the method to the analysis of isovaleric acid in the urine of a patient with isovaleric acidemia proved feasible.
Chung
Tang-Chia
TC
Graduate Institute of Pharmaceutical Sciences, Kaohsiung Medical University, Kaohsiung 807, Taiwan.
Chao
Mei-Chyn
MC
Wu
Hsin-Lung
HL
D015415:Biomarkers / Q000652:urine*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004355:Drug Stability; D045782:Hemiterpenes; D006801:Humans; D010421:Pentanoic Acids / Q000652:urine*; D015203:Reproducibility of Results
D015415:Biomarkers; D045782:Hemiterpenes; D010421:Pentanoic Acids; C008216:isovaleric acid; C038780:n-pentanoic acid