“…In order to understand the distribution of etoposide into tumor it is necessary to develop a sensitive method for quantifying the drug in different biological matrices. Several methods have been used for the determination of etoposide in plasma using high‐performance liquid chromatography (HPLC) with UV detection (Holthius et al ., ; Shirazi et al ., ; Kato et al ., ; Dhanaraju et al ., ; Zhang et al ., ), fluorescence detection (Strife et al ., ; Werkhoven‐Goewie et al ., ; Manouilov et al ., ) and electrochemical detection (Duncan et al ., ; Cai et al ., ; Pérez‐Urizar et al , ). Modern chromatographic methods, such as high‐performance liquid chromatography tandem mass spectrometry (HPLC‐MS/MS) and ultra‐performance liquid chromatography quadrupole time of flight mass spectrometry (UPLC‐qTOF‐MS/MS) have also been published for etoposide quantification in biological matrices (Liu et al ., ; Sachin et al ., ).…”