Selective Gas Chromatography Analysis of 5-Fluorouracil from Serum of Cancer Patients after Chemotherapy by Derivatization

Background: 5-Fluorouracil (5-FU) is correlated as a structural derivative of the nucleobase uracil; it is widely used as an anti-cancer drug in chemotherapy treatments.The reliability and accuracy of the quantification of 5-FU in biological fluids is essential for therapeutic monitoring.Objective: This study focuses on the development of a simple and selective analytical method for determining drug content in the serum of patients.Method: A procedure based on gas chromatography (GC) has been developed for the analysis of 5-FU from deproteinised serum of cancer patients using isobutyl chloroformate (IBCF) as a reagent.GC was performed using a DB-5 column (30 m x 0.32 mm id) connected to flame ionisation detector (FID).GC elution was carried out at a column oven temperature of 130°C for 2 min, followed by a heating rate of 15 °C/min up to 220 0 C, with a flow rate of nitrogen at 2 mL/min., with a 10:1 split ratio.Results: At the optimised conditions of derivatization and elution, the nucleobases (uracil, adenine, cytosine, thymine and guanine) were completely separated from 5-FU.The calibration curve for 5-FU was obtained with concentrations ranging from 2-50 μg/mL, with 0.06 μg/mL as the limit of detection (LOD).Conclusion: The method was repeatable with a relative standard deviation (RSD) of 2.7% (n=4).The method was used for the estimation of 5-FU from cancer patients' serum after infusion of 250 mg of 5-FU, and the amounts found were 4.6-21.2μg/mL with an RSD 2.5%.