Development and validation of a LC–MS/MS method for the quantification of tenofovir and emtricitabine in seminal plasma

Accurate and sensitive liquid-chromatography tandem mass spectrometry method for the quantification of tenofovir and emtricitabine in seminal plasma has been developed and full validated. Molecules were separated by high-performance liquid chromatography on an Atlantis T3 C₁₈ column using a gradient of deionized water and methanol, including 0.05% formic acid (250 μl/min) and detected by electrospray ionisation/tandem mass spectrometry in positive ion mode. The method was validated over a clinical range of 3.13–1000 ng/mL for tenofovir and 6.25–2000 ng/mL for emtricitabine. Inter and intra-assay precisions were <9.37% for tenofovir and<10.88% for emtricitabine, and accuracies were between 0.48% and 8.43% for tenofovir, and between 0.64% and 13.87% for emtricitabine. The developed method was successfully applied for analysing tenofovir and emtricitabine concentrations in seminal plasma samples from a clinical study. The use of tandem mass spectrometry can be a suitable method for the analysis of this kind of matrices, providing high sensitivity and specificity to the analysis.