Determination and quantification of intracellular fludarabine triphosphate, cladribine triphosphate and clofarabine triphosphate by LC-MS/MS in human cancer cells.Purine nucleoside analogues are widely used in the treatment of haematological malignancies, and their biological activity is dependent on the intracellular accumulation of their triphosphorylated metabolites.  In this context, we developed and validated a liquid chromatography tandem mass spectrometry (LC-MS/MS) method to study the formation of 5'-triphosphorylated derivatives of cladribine, fludarabine, clofarabine and 2'-deoxyadenosine in human cancer cells. 
LC-MS/MS
In this context, we developed and validated a liquid chromatography tandem mass spectrometry (LC-MS/MS) method to study the formation of 5'-triphosphorylated derivatives of cladribine, fludarabine, clofarabine and 2'-deoxyadenosine in human cancer cells. 
liquid chromatography tandem mass spectrometry
Separation was achieved on a hypercarb column. 
hypercarb column
Analytes were eluted with a mixture of hexylamine (5 mM), DEA (0.4%, v/v, pH 10.5) and acetonitrile, in a gradient mode at a flow rate of 0.3mLmin-1. 
hexylamine
Determination and quantification of intracellular fludarabine triphosphate, cladribine triphosphate and clofarabine triphosphate by LC-MS/MS in human cancer cells.Purine nucleoside analogues are widely used in the treatment of haematological malignancies, and their biological activity is dependent on the intracellular accumulation of their triphosphorylated metabolites.  Analytes were eluted with a mixture of hexylamine (5 mM), DEA (0.4%, v/v, pH 10.5) and acetonitrile, in a gradient mode at a flow rate of 0.3mLmin-1. 
DEA
Analytes were eluted with a mixture of hexylamine (5 mM), DEA (0.4%, v/v, pH 10.5) and acetonitrile, in a gradient mode at a flow rate of 0.3mLmin-1. 
acetonitrile
Multiple reactions monitoring (MRM) and electrospray ionization in negative mode (ESI-) were used for detection. 
multiple reactions monitoring
Multiple reactions monitoring (MRM) and electrospray ionization in negative mode (ESI-) were used for detection. 
electrospray ionization in negative mode