Preparation of porous aromatic framework modified graphene oxide for pipette‐tip solid‐phase extraction of theophylline in tea

Abstract

A new material called as porous aromatic frameworks modified graphene oxide (PAFs‐GO) was synthesized, and it was used as an adsorbent in pipette‐tip SPE for the effective purification and enrichment of theophylline in tea sample by HPLC. The properties of PAFs‐GO were characterized by field emission SEM, FTIR, thermogravimetry analysis and Brunauer Emmett Teller N2 adsorption‐desorption analysis. The results of static adsorption and dynamic adsorption test showed PAFs‐GO had higher adsorption ability (93.25 mg/g) than graphene oxide. The LOD and LOQ of the method were 0.0141 and 0.0471 µg/mL, respectively. The acceptable method reproducibility was found as intra‐ and inter‐day precisions, yielding the RSDs <4.62%. By introducing PAFs as support skeleton, the specific surface area of GO was effectively increased, and the penetrability was improved. Studies showed that the proposed method had been successfully applied for purification and enrichment of theophylline in complex tea matrix.

Ultra-High Adsorption Capacity of Core–Shell-Derived Magnetic Zeolite Imidazolate Framework-67 as Adsorbent for Selective Extraction of Theophylline

“…Hence, the sample pretreatment procedure to separate and enrich TP from complex samples is indispensable before chromatographic analysis. In recent years, some methods, including liquid–liquid extraction (LLE) [ 9 ], electromembrane extraction (EME) [ 10 ], pipette-tip solid-phase extraction (PT-SPE) [ 11 ], ultrasound-assisted surfactant-enhanced emulsification microextraction (UA-SEME) [ 12 ], dispersive liquid–liquid microextraction (DLLME) [ 13 ], and solid-phase extraction (SPE) [ 14 ] have been reported. However, there are some disadvantages of these methods, derived from the low extraction capacity, complicated procedures, and consumption of toxic organic solvents.…”