| 1Normorphine |
|---|
| 2Morphine |
| 3Morphine-d3 |
| 4Oxymorphone |
| 5Hydromorphone |
| 6Hydromorphone-d6 |
| 7Codeine-d6 |
| 8Codeine |
| 9O-Desmethyltramadol |
| 10Oxycodone-d6 |
| 11Oxycodone |
| 12Hydrocodone |
| 13N-Desmethyltramadol |
| 14Tramadol |
| 15Normeperidine |
| 16Normeperidine-d4 |
| 17Meperidine-d4 |
| 18Meperidine |















