Fabrication of metal-organic frameworks and graphite oxide hybrid composites for solid-phase extraction and preconcentration of luteolin

A novel solid-phase extraction sorbent , metal-organic frameworks and graphite oxide hybrid composite, was prepared by a solvothermal technique. The morphology and properties of the resultant material were examined by Fourier transform infrared spectroscopy, X-ray diffraction and field emission scanning electron microscopy . To evaluate the extraction performance of the resultant sorbent, luteolin was chosen as a model analyte. The extraction conditions were optimized. Based on these, a convenient and efficient solid-phase extraction procedure for the determination of luteolin was established and the subsequent quantification step was performed by square wave anodic stripping voltammetry . Under the optimal conditions, the oxidation current increased linearly with increasing the concentration of luteolin in the range of 5.0×10 −9 –5.0×10 −7   mol   L −1 with a correlation coefficient of 0.9983 and a detection limit of 7.9×10 −10   mol   L −1 . The relative standard deviation of seven successive scans was 4.20% for 5.0×10 −8   mol   L −1 luteolin. This work not only proposes a useful method for sample pretreatment, but also reveals the great potential of metal-organic frameworks based hybrid materials as an excellent sorbent in solid-phase extraction.