N-Doped Carbon Hollow Spheres for the Simultaneous Determination of Atorvastatin and Amlodipine by Synchronous Fluorescence Spectrofluorimetry

A green and sensitive analytical procedure by dispersive solid-phase nanoextraction (DSPNE) strategy based on mesoporous nitrogen-doped hollow carbon sphere as adsorbent is developed for the simultaneous determination of atorvastatin (AT) and amlodipine (AM) in spiked human plasma. The determination method was based on measuring the synchronous fluorescence intensity of the drugs at a constant wavelength difference (Δλ=40 nm). The different experimental parameters influencing the extraction efficiency of the two drugs were studied and optimized. The limits of detection were 3.24 and 0.406 ng. ml -1 and quantification limits were 10.8 and 1.36 ng. ml -1 for AT and AM, respectively. Validation assays indicated that the concentration ranges were linear in 11-120 for AT and 2-90 ng ml -1 for AM, with R 2 >0.993 for both drugs. Under optimum conditions, extraction recovery was 94% and 89% with RSD% 3.9 and 4.7 (n=4) for AT and AM, respectively. The developed method has been found to be simple, economical, and reproducible for the routine analysis of both drugs in biological fluids.