Table 3. Isotopic Enrichment of Salicylic Acid (SA) and Salicyluric Acid (SU) in Individual Urinesa.
| sample | SA % 13C6m/z 273/267 | SU % 13C6m/z 330/324 |
|---|---|---|
| urine 1 | 0.06 | 31.29 |
| urine 2 | 3.31 | 43.07 |
| urine 3 | 0.41 | 6.82 |
| urine 4 | 10.91 | 36.53 |
| urine 5 | 3.50 | 23.96 |
| urine 6 | 5.45 | 36.98 |
| pooled urine (no 13C6) | 0.00 | 0.00 |
| standard soln SA | 0.00 | 0.00 |
| standard soln SU | 0.00 | 0.00 |
a
Urines 1−6 show the relevant m/z ratio values, for each individual, of 13C6-labeled urinary salicylic acid (SA) and salicyluric acid (SU) SA, unlabeled 267, labeled 273 SU, unlabeled 324, labeled 330. Also shown are results for pooled, unlabeled (day 1) urine and for standard solutions of SA and SU.