| Analytes | No H3PO4 | 75 uL H3PO4 | 150 uL H3PO4 | 225 uL H3PO4 |
| Diclofenac | 290.0 | 100.0 | 79.1 | 82.4 |
| Fenoprofen | 50.0 | 100.0 | 85.1 | 85.8 |
| Flufenamic acid | 1007.2 | 100.0 | 80.2 | 70.3 |
| Flunixin | 37.8 | 100.0 | 87.5 | 90.2 |
| Indomethacin | 185.3 | 100.0 | 84.0 | 82.3 |
| Indoprofen | ND | 100.0 | 88.4 | 84.4 |
| Ketoprofen | 20.2 | 100.0 | 81.1 | 75.0 |
| Ketorolac | 3.3 | 100.0 | 84.4 | 77.5 |
| Meclofenamic acid | 591.9 | 100.0 | 96.4 | 101.3 |
| Mefenamic acid | 539.7 | 100.0 | 86.4 | 81.3 |
| 6-MNA | 3.5 | 100.0 | 98.1 | 98.3 |
| Naproxen | 5.3 | 100.0 | 87.1 | 85.6 |
| Oxyphenbutazone | 40.4 | 100.0 | 95.1 | 93.5 |
| Phenylbutazone | 90.9 | 100.0 | 102.7 | 98.2 |
| Tolmetin | 5.2 | 100.0 | 77.3 | 64.3 |
| Zomepirac | 9.7 | 100.0 | 73.5 | 54.5 |