Reduced Graphene Oxide-Cadmium Sulfiide Quantum Dots Nanocomposite Based Dispersive Solid Phase Microextraction for Ultra-Trace Determination of Carbamazepine and Phenobarbital

This research presents a fast, sensitive, and selective ultrasound-assisted dispersive solid phase microextraction technique for simultaneous preconcentration and determination of ultra-trace amount of carbamazepine and phenobarbital. Reduced graphene oxide sheets decorated with cadmium sulfide quantum dots was synthesized, characterized, and used as a high capacity adsorbent. A high performance liquid chromatography with UV detector (HPLC-UV) instrument with 58:42 composition of methanol:acetic acid/acetate buffer (pH = 5; 0.05 mol L-1) as the mobile phase and set on the wavelength of 230 nm was used to separate and quantify the analytes. In this regard, different parameters affecting adsorption and desorption of the analytes on the surface of the nanocomposite were studied and optimized to maximize the efficiency of the method. The method was linear in the ranges of 0.5-180 and 0.5-140 ng mL(-1) (correlation coefficient (r) > 0.999) with limits of detection of 0.19 and 0.24 ng mL(-1) for carbamazepine and phenobarbital, respectively. Eventually, to evaluate the efficiency of the proposed method for the determination of pharmaceuticals in biological samples, different real samples including breast milk, urine and human plasma were tested. Obtained recoveries values were within the range of 96.3 +/- 2 to 103.7 +/- 3.3% which showed satisfactory efficiency.

Automated summary

This study introduced a fast, sensitive, and selective ultrasound-assisted dispersive solid phase microextraction technique for the simultaneous preconcentration and determination of ultra-trace amounts of carbamazepine and phenobarbital. The method utilized reduced graphene oxide sheets decorated with cadmium sulfide quantum dots as a high capacity adsorbent, and high performance liquid chromatography with UV detector for analysis. The efficiency of the method was evaluated through testing on various real samples, showing satisfactory recoveries.