Compilation of gas chromatographic retention indices of 163 metabolically important organic acids, and their use in detection of patients with organic acidurias

Gas chromatographic retention indices have been compiled for 163 metabolically important compounds (mostly organic acids) in the form of methylene units, as trimethylsilyl derivatives, on 10% OV-1 and 10% OV-17 columns. Comprehensive references on metabolic diseases that can be diagnosed by detection of these metabolites are cross-indexed to facilitate the use of the methylene-unit list. The gas chromatographic method, which utilizes extraction of urine with ethyl acetate and trimethylsilylations, is described. Modified methods, one for neutral compounds and one for highly polar organic acids, both of which utilize appropriate ion exchange and lyophilization, are also described. Practical applications of these methods and the use of the methylene-unit in the diagnosis of eleven patients with various metabolic disorders are also shown.