Among the metal oxide available as the sorbent for microextraction purposes, cobalt oxide/hydroxide are desirable candidates due to their natural abundance, low cost, large surface-to-volume ratio, good adsorption ability, high stability and environmental compatibility [1]. These unique features of Co3O4 make it suitable for the extraction or removal of organic compounds. In this study, hierarchical flowerlike cobalt oxide coated anodized aluminium foil was prepared by in-situ conversion of fabricated Co-Al layered double hydroxide as template. the, Co-Al-LDH precursor has been fabricated on nonporous anodic aluminum film via the in-situ crystallization technique. The Al foil substrate was anodized using fast electrochemical technique. The prepared flowerlike cobalt oxide was used as a novel sorbent in thin film microextraction (TFME) method followed by high performance liquid chromatography-ultraviolet detection (HPLC-UV). 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, diclofenac was selected as model analyte. Diclofenac was determined by high performance liquid chromatography-ultraviolet detection (HPLC-UV). Plackett–Burman design was used for screening the experimental factors of interest. The screened factors were then optimized using Box-Behnken design (BBD). To investigate the capability of the prepared film in real sample analysis, urine and plasma samples were selected as real samples.
