A simplified dispersive solid-phase extraction using a shaped zirconium-based metal-organic framework: Constructing a novel, facile and efficient method for detecting plant growth regulators in citrus fruits.

A facile, efficient and reliable method was designed and established to analyze the plant growth regulators (PGRs) in citrus fruit, based on a simplified dispersive solid-phase extraction (d-SPE) using a shaped zirconium-based metal-organic framework (UiO-66-PDMS bead) as the sorbent. In this method, UiO-66-PDMS beads directly extracted the targets from the homogenized and could be easily separated with a tweezer. It avoided the centrifugation or filtration operation required in normal d-SPE, greatly simplifying the d-SPE process. Moreover, the matrix substances were efficiently removed by this d-SPE process. The method showed good linearities (R2 ≥ 0.9995) and limits of detection (0.09-0.17 ng/g). The recoveries were in the range of 80.7-97.5 %. The intra-day and inter-day precisions were 1.5-6.3 % and 4.6-11.7 %, respectively. Additionally, the adsorption interactions between UiO-66-PDMS bead and PGRs were studied by ATR-FTIR and UV-vis DRS. Furthermore, the method was employed to screen the PGRs in ten different citrus fruits.