Gas chromatography—mass spectrometry studies of hipuric acid derivatives : I. Evaluation of methods for quantiative determination of hippuric acid. A search for benzoylsarcosine excretion in normal urine
✍ Scribed by U. Langenbeck; J.E. Seegmiller
- Publisher
- Elsevier Science
- Year
- 1973
- Tongue
- English
- Weight
- 652 KB
- Volume
- 80
- Category
- Article
- ISSN
- 1873-3778
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✦ Synopsis
Hippuric acid can be determined, after conversion to its methyl ester with diazomethane, by gas chromatography on cyclohexane dimethanol succinate. Constant response factors are obtained with the methyl esters of either stearic or palmitic acid as internal standards. Benzoic acid can also be determined as its methyl ester in this system.
By on-column methylation with trimethylpl~enylammonium hydroxide, hippuric acid yields hippuric acid methyl ester and benzoylsarcosine methyl ester. Benzoylsarcosine was not detected in normal urine after ingestion of benzoic acid. With trimethylsilyl as well as with the methyl derivatives of hippuric acid, the rule is confirmed that a higher methyl content leads to decreased elution times on silicon phases.