Field-amplified sample injection-capillary zone electrophoresis method for the analysis of 5-fluorouracil anticancer drug

Abstract

Field-amplified sample injection-capillary zone electrophoresis (FASI-CZE) method was developed to enhance the detection sensitivity of anticancer drug 5-fluorouracil (5-FU). The analyte was introduced electrokinetically for 5 s into a capillary loaded with highly conductive background electrolyte (BGE). The injected analyte migrated in negative polarity, reducing separation time to 5 minutes as compared to positive polarity in hydrodynamic injection-CZE (18 minutes). FASI-CZE was optimized based on three parameters: Sample injection time (5 s, 10 s, and 40 s), BGE concentration in sample (3 mM, 5 mM, and 10 mM) and BGE concentration (15 mM and 25 mM). Optimization of FASI-CZE was conducted to achieve optimal conditions as followed: 15 mM borate BGE containing 0.1% w/v hexadimethrine bromide (HDMB), 5-FU and 5-BrU (IS) prepared in 5 mM diluted BGE, 20% v/v organic modifier in mixture sample was injected at-5 kV for 5 s. The separation was conducted using-25 kV and detected at the wavelength of 234 nm in diode array detection (DAD). The precision was reasonable; %RSD 4.43% at low concentration levels (5 mg/L). The LOD value was 0.24 mg/L when applied with FASI as compared to 0.58 mg/L using HDI-CZE. The sensitivity enhancement factor (SEF) was almost 3 times higher than HDI-CZE at positive polarity, showing that the proposed of FASI-CZE approach is appropriate for the study of 5-FU at trace level.