Table 1. Analytical variability in urinary metabolites measured in 1H NMR spectra in 24 repeat urine samples (pooled representative QC sample) and in 50:50 pool samples.
| Metabolite | resonance signal (ppm) | integrated region | Signal/Noise ratio (log10) | CV (Quality control sample, N = 24) | %DiffPool (50:50 samples, N = 108) | ChEBI ID** | |
|---|---|---|---|---|---|---|---|
| lower bound (ppm) | upper bound (ppm) | ||||||
| 2-hydroxyisobutyrate | 1.36 (s) | 1.362 | 1.366 | 3.57 | 7.3% | 3.9% | 19641 |
| 3-aminoisobutyrate* | 2.63 (m) | 2.617 | 2.633 | 2.94 | 17.5% | 21.5% | 49096 |
| 3-hydroxybutyrate/3-aminoisobutyrate | 1.19 (d) | 1.187 | 1.194 | 3.45 | 7.1% | 4.9% | 37054/49096 |
| 3-hydroxyisobutyrate | 1.08 (d) | 1.078 | 1.084 | 3.35 | 5.6% | 4.8% | 11805 |
| 3-hydroxyisovalerate | 1.27 | 1.272 | 1.276 | 3.67 | 7.5% | 4.3% | 82957 |
| 3-indoxylsulfate | 7.52 | 7.514 | 7.52 | 2.95 | 7.3% | 8.5% | 43355 |
| 4-deoxyerythronic acid | 1.1 | 1.103 | 1.107 | 3.24 | 8.3% | 6.3% | 86347 |
| 4-deoxythreonic acid | 1.24 | 1.239 | 1.244 | 3.48 | 5.5% | 4.4% | 86391 |
| 5-oxoproline | 2.39 | 2.391 | 2.397 | 3.23 | 5.6% | 7.2% | 16010 |
| Acetate | 1.93 | 1.926 | 1.93 | 3.37 | 10.2% | 10.2% | 30089 |
| Acetone | 2.24 | 2.238 | 2.241 | 2.67 | 15.6% | 19.3% | 15347 |
| Alanine | 1.49 | 1.489 | 1.497 | 3.91 | 4.1% | 2.2% | 16977 |
| Carnitine | 3.23 | 3.227 | 3.235 | 4.13 | 12.1% | 18.7% | 17126 |
| Citrate | 2.54 | 2.514 | 2.575 | 4.91 | 6.6% | 5.5% | 30769 |
| Creatine | 3.94 | 3.934 | 3.94 | 5.05 | 4.5% | 2.7% | 16919 |
| Creatinine | 4.06 | 4.05 | 4.072 | 5.44 | 5.7% | 3.1% | 16737 |
| Dimethylamine | 2.73 | 2.72 | 2.736 | 4.51 | 4.2% | 2.8% | 17170 |
| Formate | 8.47 | 8.463 | 8.467 | 3.53 | 8.4% | 5.2% | 15740 |
| Glucose* | 5.25 | 5.24 | 5.261 | 3.72 | 2.8% | 2.7% | 17234 |
| Glutamine | 2.46 | 2.435 | 2.475 | 4.39 | 12.6% | 11.0% | 28300 |
| Glycine | 3.57 | 3.572 | 3.576 | 4.46 | 7.4% | 3.8% | 15428 |
| Hippurate | 7.56 | 7.538 | 7.574 | 4.47 | 2.4% | 3.3% | 132966 |
| Isoleucine | 1.02 | 1.018 | 1.023 | 2.42 | 9.4% | 10.9% | 24898 |
| Lactate | 1.33 | 1.329 | 1.336 | 3.75 | 5.9% | 3.8% | 24996 |
| Leucine | 0.97 | 0.963 | 0.969 | 2.96 | 6.4% | 4.6% | 25017 |
| Lysine | 1.74 | 1.715 | 1.756 | 3.80 | 2.3% | 4.5% | 25094 |
| N1-methylnicotinamide | 9.28 | 9.265 | 9.292 | 2.83 | 12.7% | 10.7% | 16797 |
| N-acetylneuraminic acid* | 2.06 | 2.054 | 2.071 | 4.01 | 4.4% | 3.9% | 45744 |
| N-methyl-2-pyridone-5-carboxamide | 6.67 | 6.66 | 6.681 | 3.13 | 9.2% | 15.4% | 27410 |
| N-methylnicotinic acid | 9.12 | 9.11 | 9.135 | 3.07 | 9.0% | 7.3% | 50521 |
| N-methylpicolinic acid | 8.71 | 8.698 | 8.725 | 1.70 | 22.0% | 60.3% | 69061 |
| Pantothenic acid | 0.94 | 0.933 | 0.938 | 3.07 | 6.0% | 3.7% | 7916 |
| p-cresol sulfate | 2.35 | 2.343 | 2.349 | 4.11 | 5.7% | 4.2% | 82914 |
| p-hydroxyphenylacetate | 6.87 | 6.871 | 6.878 | 3.23 | 7.8% | 5.7% | 18101 |
| Proline betaine | 3.3 | 3.301 | 3.308 | 3.83 | 11.0% | 20.3% | 35280 |
| Scyllo-inositol | 3.36 | 3.362 | 3.367 | 3.67 | 10.8% | 9.4% | 10642 |
| Succinate | 2.41 | 2.41 | 2.414 | 3.85 | 11.5% | 19.6% | 26806 |
| Sucrose | 5.42 | 5.41 | 5.425 | 3.18 | 3.7% | 8.5% | 17992 |
| Taurine | 3.43 | 3.419 | 3.45 | 4.67 | 3.2% | 5.9% | 15891 |
| Trimethylamine | 2.87 | 2.868 | 2.872 | 3.59 | 8.3% | 7.3% | 18139 |
| Trimethylamine-N-oxide | 3.28 | 3.265 | 3.285 | 5.00 | 2.5% | 7.9% | 15724 |
| Tyrosine | 6.91 | 6.905 | 6.912 | 3.20 | 8.2% | 5.3% | 18186 |
| Urea | 5.81 | 5.675 | 5.95 | 5.96 | 4.1% | 2.7% | 16199 |
| Valine | 1.04 | 1.039 | 1.044 | 2.93 | 6.7% | 4.5% | 27266 |
*Multiple overlapping resonances. Integral assigned to the most likely, abundant metabolite. **Chemical Entities of Biological Interest (ChEBI), dictionary of molecular entities available online at http://www.ebi.ac.uk/chebi/. For metabolites with chiral enantiomers, the ID without L or D specification was selected since both forms may be present in human urine.