Electrochemically preparation of Co-Al layered double hydroxide nanosheets on nanoporous anodic aluminum oxide /aluminum film as thin film microextraction film

Herein, a facile hydrothermal method was used to grow a very thin nanosheets of Co-Al layered double hydroxide (Co-Al-LDH) on an anodized aluminum foil for the first time. In this study, a hierarchical Co-Al-LDH has been fabricated via the in situ crystallization technique on nonporous anodic aluminum film. Before the hydrothermal process, the Al foil substrate was potentially anodized. The prepared film with high surface area and compact structure was used as a novel sorbent in thin film microextraction (TFME) method. After extraction, the extracting film was eluted using organic solvent to desorb the target analyte. In order to evaluate the extraction ability of the prepared film, quercetin was selected as target analyte. To investigate the capability of the prepared film in real sample analysis, different kinds of fruit juice was selected. Plackett–Burman design was used for screening the experimental factors of interest in TFME. Thereafter, the effective factors were optimized using Box-Behnken design (BBD). LDHs are an example of interesting emerging materials for extraction applications [1]. LDHs are 2D nanostructured materials consisting of positively charged, brucite-like octahedral layers of metal hydroxides and a negatively charged interlayer region containing anions and water molecules [2]. LDHs are represented by the general formula [M2+ 1–x M3+ x (OH)2]x+ (An–)x/n. mH2O, where M2+ is a divalent cation, M3+ is a trivalent cation and An– is the interlayer anion. LDHs have a high surface area, anion exchange properties, good thermal stability and tunable and flexible interlayer spaces.