A Microcrystalline Cellulose/Metal-Organic Framework Hybrid for Enhanced Ritonavir dispersive solid phase microextraction from Human Plasma

A hybrid of microcrystalline cellulose (MCC) with metal organic frame (MOF) was developed as an efficient adsorbent for dispersive solid phase microextraction (dSPME) of ritonavir from spiked human plasma. The developed sorbent was characterized by a high-resolution scanning electron microscope (HR-SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). The MCC was immersed in a solution of CaCl2, stirred with soda water and 1,3,5-benzenetricarboxylic acid, resulting in white MCC/MOF composites, which were separated, washed, and dried. The MCC/MOF hybrids were examined under the HR-SEM and showed morphological features different form the MCC and Ca-1,3,5-benzenetricarboxylic acid (Ca-BTC) MOF. The diffraction patterns of Ca-BTC/MCC composites clearly displayed the characteristic Ca-BTC MOF diffraction bands, indicating that MCC was successfully incorporated in the formation of crystalline MOF hybrids. The FTIR spectra exhibited the bands of MCC, as well as the bands of Ca-BTC MOFs. The prepared Ca-BTC/MCC MOF was applied for dSPME of ritonavir from human plasma, before the determination by high performance liquid chromatography with UV detection. After method optimization, the best extraction efficiency was achieved by using 12.50 mg of Ca-BTC/MCC MOF as a sorbent and 250 µL of acetonitrile as an eluent. This novel sorbent (Ca-BTC/MCC) merges the advantages of the high surface areas of MOFs 820 m2 g-1 with the biodegradability and sustainability of MCC. Besides, Ca-BTC/MCC exhibited higher extraction efficiency compared with unmodified Ca-BTC MOF. To the best of our knowledge, this work applies the Ca-BTC/MCC sorbents for dSPME of ritonavir in human plasma, for the first time. These results open the door to more applications of these composites in sample preparation for biomedical analysis.