SPME fiber coated by arrayed ZNRs for sampling and concentration of polar residual solvents for further analysis using GC FID.

In this work, fused silica coated by arrayed ZNRs were successfully applied as a sorbent for analysis of polar residual solvents in pantoprazole feedstocks. ZnO nanoparticles were produced and deposited on a fused silica surface applying the dip coating technique and hydrothermal growth to synthesize the arrayed nanorods. The ZNRs array fiber coating was characterized by SEM, EDS, XRD, and TGA. The manufactured SPME fiber was coupled to a glass syringe of 10 µL and applied for the sampling of acetone, n-butanol, dichloromethane, ethyl acetate and methanol for further analysis using GC FID. Optimum operating conditions were determined for the incubation temperature (70 °C), incubation time (15 min), extraction time (120 s), and desorption time (0.6 min). Employing the optimum conditions, the proposed method resulted in a good linearity (> 0.997) and precision (< 7.1%) for the evaluated analytes. Recovery tests were also performed on three levels (below, equal to and above the ICH specification limit for residual solvents in pharmaceutical products). Recoveries ranging from 96% to 107% were obtained. Comparison between the reference method and developed method shows errors smaller than 4%.