| R-(-)-Bicalutamide and S-(+)-Bicalutamide | Oncology | LC/MS/MS | 1 - 2000 ng/mL-0.5-2000 ng/mL | Human EDTA K3 Plasma |
| R-(-)-Bicalutamide; S-(+)-Bicalutamide | Oncology | LC/MS/MS | 5-1000 ng/ml; 5-200 ng/ml | Human EDTA Plasma |
| R-(+)-Sibutramine; S-(-)-Sibutramine | Central Nervous System Agents | LC/MS/MS | 50-2000 pg/ml | Human EDTA plasma |
| R-(+)-Sibutramine; S-(-)-Sibutramine | Nervous sistem agent | LC/MS/MS | R-Sibutramine 15-7500 pg/mL; S-(-)-Sibutramine 15-3000pg/mL | HUMAN SODIUM HEPARINIZED PLASMA |
| R/S-Zopiclone (chiral method) | Central Nervous System Agents | LC/MS/MS | 1-100 ng/mL | Human EDTA Plasma |
| Rabeprazole | Gastrointestinal | LC/MS/MS | 2-1000 ng/mL | Human EDTA Plasma |
| Racecadotril | Gastrointestinal | LC/MS/MS | 10-5000 pg/mL | Human Plasma |
| Raloxifene | Rheumatology | LC/MS/MS | 10-500 pg/mL | Human EDTA Plasma |
| Raloxifene-4'-glucuronide; Raloxifene-6-glucuronide | Rheumatology | LC/MS/MS | 2 - 200 ng/mL; 0.4 - 40 ng/mL | Human EDTA Plasma |
| Raloxifene-6-glucuronide | Rheumatology | LC/MS/MS | 0.6-150 ng/ml; 0.3-75 ng/ml | Human EDTA Plasma |
| Ramipril; Ramiprilat | Cardiovascular | LC/MS/MS | 200-80000 pg/mL; 200-80000 pg/mL | Human EDTA Plasma |
| Ramipril; Ramiprilat | Cardiovascular | LC/MS/MS | 100-40000 pg/mL | Human EDTA Plasma |
| Ranitidine | Gastrointestinal | LC/MS/MS | 4-1600 ng/mL | Human EDTA Plasma |
| Rasagiline | TBD | LC/MS/MS | 50-10000 pg/mL | Human EDTA Plasma |
| Repaglinide | Endocrinology | LC/MS/MS | 0.1-50 ng/mL | Human EDTA Plasma |
| Repaglinide | Endocrinology | LC/MS/MS | 100-25000 pg/mL | Human EDTA Plasma |
| Rhein | Miscellaneous | LC/MS/MS | 50-5000 ng/mL | Human EDTA Plasma |
| Ribavirin | Infectious Disease | LC/MS/MS | 10-5000 ng/mL | Human EDTA Plasma |
| Rifampin | TBD | LC/MS/MS | 50-12500 ng/mL | Human Whole Blood |
| Rifaximin | Infectious Disease | LC/MS/MS | 50-5000 pg/mL | Human Plasma |
| Riluzole | Central Nervous System Agents | LC/MS/MS | 0.5-500 ng/mL | Human EDTA Plasma |
| Risedronic Acid | Endocrinology, Rheumatology | LC/MS/MS | 200-50000 pg/mL | Human EDTA Plasma |
| Risperidone; 9-hydroxyrisperidone | Central Nervous System Agents | LC/MS/MS | 100-30000 pg/mL ; 100-15000 pg/mL | Human EDTA Plasma |
| Risperidone; 9-hydroxyrisperidone | Central Nervous System Agents | LC/MS/MS | 100-50000 pg/mL ; 100-25000 pg/mL | Human EDTA Plasma |
| Ritalinic acid | Central Nervous System Agents | LC/MS/MS | 1-250 ng/mL | Human EDTA Plasma |
| Ritonavir | Infectious Disease | LC/MS/MS | 5-1000 ng/mL | Human EDTA Plasma |
| Rivastigmine | Central Nervous System Agents | LC/MS/MS | 100-10000 pg/mL | Human EDTA Plasma |
| Rivastigmine and metabolite | Central Nervous System Agents | LC/MS/MS | 0.2-30 ng/mL | Human EDTA K3 Plasma |
| Rizatriptan | Pain | LC/MS/MS | 100-40000 pg/mL | Human EDTA Plasma |
| Rizatriptan; N-Desmethyl Rizatrptan | Pain | LC/MS/MS | 100-40000 pg/mL;10-4000 pg/mL | Human EDTA Plasma |
| Ropinirole | Central Nervous System Agents | LC/MS/MS | 5-1000 pg/mL | Human EDTA Plasma |
| Rosiglitazone | Endocrinology | LC/MS/MS | 2-900 ng/mL | Human EDTA Plasma |
| Rosuvastatin | Cardiovascular | LC/MS/MS | 80-40000 pg/mL | Human EDTA Plasma |
| R-Selegiline | Central Nervous Agents | LC/MS/MS | 50-5000 ng/mL | Human EDTA Plasma |
| R-Selegiline, N-Desmethyl Selegiline, L-Amphetamine and L-Methamphetamine | Central Nervous System Agents | LC/MS/MS | 10-10000 pg/mL, 50-5000 pg/mL, 20-8000 pg/mL and 20-8000 pg/mL | Rat Plasma |
| R-Selegiline, N-Desmethyl Selegiline, L-Amphetamine and L-Methamphetamine | Central Nervous System Agents | LC/MS/MS | 40-8000 pg/mL, 100-20000 pg/mL, 50-20000 pg/mL and 50-20000 pg/mL | Human Urine |
| R-Selegiline, N-Desmethyl Selegiline, L-Amphetamine and L-Methamphetamine | Central Nervous System Agents | LC/MS/MS | 50-5000 pg/mL, 25-2500 pg/mL, 20-2500pg/mL and 15-6000 pg/mL | Human EDTA Plasma |
| R-Selegiline, N-Desmethyl Selegiline, L-Amphetamine and L-Methamphetamine | Central Nervous System Agents | LC/MS/MS | 10-10000 pg/mL, 50-5000 pg/mL, 20-8000 pg/mL and 20-8000 pg/mL | Rabbit EDTA Plasma |