In-situ synthesis of flower like CoO nanorod arrays on anodized aluminum substrate templated from layered double hydroxide as a nanosorbent for thin film microextraction of acidic drugs followed by HPLC-UV quantitation.

The present study is the first report of in-situ growth and application of nanorods-flower like CoO nanosorbent coated on the anodized aluminum substrate for thin film microextraction (TFME) approach. The flower like CoO was successfully fabricated by conversion of Co-Al layered double hydroxide (LDH) precursor to CoO using the simple calcinations process. The cheap and available aluminum foil was electrochemically anodized and used as a porous substrate. Response surface methodology (RSM) was explored for optimization step. Different acidic drugs, including: paracetamol, ibuprofen, aspirin and diclofenac were extracted from biological fluids in order to investigate the capability of the prepared sorbent. The extracted analytes were then analyzed using high performance liquid chromatography-ultraviolet detection (HPLC-UV). Under the optimized conditions, the limits of detection were between 0.2 and 1.7 µg L in different selected matrices. The obtained limits of quantification were also calculated to be between 0.8 and 5.1 µg L in the selected matrices. In addition the enrichment factors were also in the range of 105-169. Batch-to-batch reproducibility at 100 µg L concentration level was also evaluated to be lower than 5.2% (n = 3). Finally, the method was successfully used for analysis of these compounds in the biological fluids.