Related Experiment Videos
A simplified and rapid quantitative assay for propionic and methylmalonic acids in urine
The Journal of Laboratory and Clinical Medicine
|March 1, 1975
Summary
This study presents a rapid gas chromatography method for simultaneously measuring propionic and methylmalonic acids in urine. The technique accurately quantifies these organic acids, aiding in diagnosing metabolic disorders.
Area of Science:
- Clinical Chemistry
- Metabolic Disorders
- Analytical Chemistry
Background:
- Propionic aciduria and methylmalonic aciduria are metabolic disorders.
- These conditions can occur independently or together in vitamin B12 deficiency.
Purpose of the Study:
- To develop a rapid, simultaneous method for extracting and quantifying propionic and methylmalonic acids in urine.
- To establish a reliable diagnostic tool for specific inborn errors of metabolism and vitamin B12 deficiency.
Main Methods:
- Simultaneous extraction of propionic and methylmalonic acids from urine.
- Gas chromatography assay utilizing selective decarboxylation of methylmalonic acid at 225°C.
- Quantification via peak height ratio analysis with ethylmalonic acid as an internal standard.
Main Results:
- Methylmalonic acid quantitatively decarboxylates to propionic acid at 225°C.
- Endogenous propionic acid is measured at 130°C, where methylmalonic acid is stable.
- The assay achieves high resolution for propionic aciduria (≥0.5 mg/L) and methylmalonic aciduria (≥5 mg/L).
Conclusions:
- A rapid (approx. 2-hour total running time) and accurate gas chromatographic method for simultaneous analysis of propionic and methylmalonic acids has been developed.
- This method provides excellent resolution for diagnosing conditions characterized by elevated levels of these organic acids.
- The assay is suitable for clinical settings requiring timely diagnosis of metabolic disturbances.