Adsorptive stripping voltammetric determination of anticancer drug lomustine in biological fluids using in situ mercury film coated graphite pencil electrode

•In situ mercury film coated graphite pencil electrode (MF/GPE) was applied for determination of lomustine (LMT).•Parameters optimization for preparation of MF/GPE was examined.•The modified electrode showed high sensitivity in wide linear range and low detection limit.•The electrochemical parameters for the reduction of LMT at the MF/GPE were calculated.•The modified electrode was successfully applied for determination of LMT in human fluids.

In situ mercury film coated graphite pencil electrode (MF/GPE) was prepared and applied for selective and sensitive electrochemical determination of anticancer drug lomustine (LMT). Parameter optimization for the preparation of MF/GPE was examined. The bare and modified GPEs were characterized by scanning electron microscopy (SEM), cyclic voltammetry and square wave voltammetry. With pH 5.0, Britton–Robinson (BR) buffer and in the presence of 0.5 M sulfate ions as indifferent supporting electrolyte, LMT yields a well defined and sensitive reduction peak at the MF/GPE. The electrochemical parameters such as the charge value (Q), surface concentration (Γ), electron transfer coefficient (α) and the standard rate constant (ks) for the reduction of LMT at the MF/GPE were calculated. The achieved limits of detection and quantification were 8.13 × 10− 8 M and 2.71 × 10− 7 M by square wave cathodic adsorptive stripping voltammetry (SWCASV), respectively. The modified MF/GPE was used as a sensor for the detection of LMT in human blood and urine samples with good accuracy and precision.

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