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Updated: Aug 11, 2026

One-step Metabolomics: Carbohydrates, Organic and Amino Acids Quantified in a Single Procedure
Published on: June 25, 2010
Early identification of isovaleric aciduria using photodiode array detection for liquid chromatographic profiling of
1Dept. Pediatrics, University of Michigan, Ann Arbor 48109.
Abstract:
The 190 nm high performance liquid chromatographic photodiode array profiling of the urinary carboxylic acids of the first urine of a newborn affected with isovaleric aciduria afforded an abnormal peak at 27.8 min. This peak was greatly increased in the carboxylic acid profiling of the 14 h urine sample from the same infant. Isolation of this peak by fraction collecting; solvent extraction of the eluent; trimethylsilyl derivatization of the residue and gas chromatographic/mass spectrometric analysis identified the compound as isovalerylglycine. Correlation of the 190 nm absorbance of isovalerylglycine (y) with concentration (x) afforded a least squares curve: y = 476.4x-13.72 (r = 0.99); run-to-run variation 6.92%; day-to-day variation 8.88% with a minimum detectable concentration of 25 micrograms/ml.
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