Quantitation of tenofovir and emtricitabine in dried blood spots (DBS) with LC-MS/MS

- Measurement of TFV and FTC in dried blood spot to 2.5 ng/mL.
- DBS storage requires −20 °C or below because phosphate anabolites degrade to TFV.
- Measurement was accurate and precise for hematocrit spanning the normal range.
- Measurement was not impacted by punch location and spot volumes (10-50 μL).
- DBS can be used as a plasma alternative for pharmacokinetic analyses in vivo.