Liquid chromatographic method for the determination of sirolimus in blood using electrochemical detection

Wide electrochemical window of screen-printed electrode for determination of rapamycin using ionic liquid/graphene composites

A disposable screen-printed carbon electrode (SPCE) modified with an ionic liquid/graphene composite (IL/G) exhibits a wider potential window, excellent conductivity, and specific surface area for the improvement in the voltammetric signal of rapamycin detection. The modified composite was characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), and electrochemical impedance spectroscopy (EIS). The electrochemical behavior of rapamycin at the modified SPCE was investigated by cyclic and square wave voltammetry in 60:40 EtOH: 0.1 M LiClO₄ at pH 5.0. A high reproducible and well-defined peak with a high peak current were obtained for rapamycin detection at a position potential of + 0.98 V versus Ag/AgCl. Under the optimized conditions, the rapamycin concentration in the range 0.1 to 100 μM (R² = 0.9986) had a good linear relation with the peak current. The detection limit of this method was 0.03 μM (3SD/slope). The proposed device can selectively detect rapamycin in the presence of commonly interfering compounds. Finally, the proposed method was successfully applied to determine rapamycin in urine and blood samples with excellent recoveries. These devices are disposable and cost-effective and might be used as an alternative tool for detecting rapamycin in biological samples and other biological compounds. Graphical abstract Schematic presentation of wide electrochemical window and disposable screen-printed sensor using ionic liquid/graphene composite for the determination of rapamycin. This composite can enhance the oxidation current and expand the potential for rapamycin detection.

Antineoplastic drugs and their analysis: a state of the art review

We provide an overview of the analytical methods available for the quantification of antineoplastic drugs in pharmaceutical formulations, biological and environmental samples.

Development of a validated high-throughput LC-ESI-MS method for determination of sirolimus on dried blood spots

A high-throughput liquid chromatography-electrospray ionization mass spectrometric (LC-ESI-MS) method for screening of sirolimus on dried blood spots (DBS) was developed and validated. It involves solvent extraction of a punch of DBS followed by reversed-phase LC on a relatively new monolithic column consisting of a silica rod with bimodal pore structure and detection by ESI-MS. The run time was less than 3 min with a very low backpressure at a flow rate of 0.5 mL/min. The method can analyze more than 100 samples in an 8 h working day, including sample preparation. The assay was linear from 1 to 100 ng/mL. The mean recovery was 92.42%. The mean inter-day and intra-day precisions were 1.23 and 1.41%, respectively. The developed method is simple, rapid and useful for clinical applications.