There were performed subsequent measurements of NMR
spectra on the samples of unprocessed urine of 6 patients
[10,11] suffering from propionic acidaemia and methylmalonic
aciduria and identified the protons of MCA diastereoisomers 3-
hydroxypropionic acid and methylmalonic acid. Moreover, three
samples of references of urine were measured. The proton shifts of
mostmetabolites arepH-dependent. Therefore,for accurate assignment
of resonance and to avoid mistakes (due to the presence of
different metabolites), the spectra were measured at pH 2.5 and
12.5. On the basis of the experiments [10] there was confirmed a
presence in the test samples of the two diastereoisomers of MCA
(2S, 3S) and 45–53% (2R, 3S) 47–55%, depending on the disease. The
results obtained were used in determining the amount and ratio
of the diastereoisomers MCA analysis of urine samples of patients
with above-mentioned metabolic disease