Hydroxyapatite surface-functionalized monolithic column for selective in-tube solid phase microextraction of zoleronic acid and risedronic acid

To date, hydroxyapatite (HAP) based monoliths were mainly fabricated by directly doping of HAP, which suffered from less effective coverage of HAP. Herein, a HAP surface-functionalized monolithic column (HAP@PDA@UF) has been prepared by in-situ biomineralization and applied as sorbent for selective in -tube solid phase microextraction of zoleronic acid and risedronic acid. A polydopamine coating was first generated on the surface of the parent urea-formaldehyde resin monolith; and then HAP microcrystals were further grew on the polydopamine coating to achieve this preparation. SEM, EDAX, FTIR, XPS and mercury intrusion method were utilized for the characterization of the HAP@PDA@UF monolith, and pro-vided evidences of this successful preparation. The selective extraction mechanism of the HAP@PDA@UF monolith was investigated by the optimization of methanol percentage in the sampling solution, phos-phate concentration in the eluent. Other crucial factors, including sampling and elution flow rate, and collection time span, were also optimized for the desired SPME performance. Under the optimal condi-tions, the proposed method showed low LODs of 0.1 mu g/mL, satisfactory recoveries of 79.6%-92.5% with RSDs less than 2.7%, and good reproducibility with RSD less than 6.9%, which demonstrated the excellent application of the HAP@PDA@UF monolith, and its potential as a promising selective sorbent for bispho-sphonates. (c) 2021 Elsevier B.V. All rights reserved.

Automated summary

In this study, a HAP surface-functionalized monolithic column was prepared and applied for the selective in-tube solid phase microextraction of zoleronic acid and risedronic acid. Through characterization of the monolith and investigation of the selective extraction mechanism, optimal conditions were identified for the desired analytical performance.