Development of an LC-MS/MS assay for the quantitative determination of the intracellular 5-fluorouracil nucleotides responsible for the anticancer effect of 5-fluorouracil

- We developed an LC-MS/MS assay to quantify the active 5-FU nucleotides in PBMCs.
- Release from the cell matrix and endogenous interference were carefully optimized.
- First time 5-FU nucleotides were quantified in patient cells without radiolabel.