Determination of celecoxib with a dispersive micro solid-phase extraction coupled with UV-Vis spectrophotometric method in milk, urine and water samples

A sensitive, straightforward, and inexpensive dispersive micro solid-phase extraction (DµSPE) coupled with the spectrophotometric method was developed for measuring celecoxib in biological and water samples. For this purpose, a new sorbent (Nickel nanoparticles doped carboxyl graphene oxide) was synthesized using a simple chemical procedure and was utilized to extract celecoxib. The effective factors in the DµSPE procedure were evaluated and optimized by the design of experiment method. Two designs, including the Plackett-Burman design and Box-Behnken design, were applied to screening significant factors and to optimize the significant factors, respectively. The DµSPE- spectrophotometric method was linear in the concentration range of 0.004-3.5 µg mL-1 with an R-squared of 0.9951 for the celecoxib measurement under the optimum conditions. The method showed a low limit of detection of 0.004 µg mL-1 and a suitable enrichment factor of 21.7 for the analyte determination. The relative standard deviation was calculated for five measurements of the standard solution of celecoxib with a concentration of 0.3 µg mL-1 and was 3.2%. Finally, the proposed method was used to analyze real samples such as milk, urine, and tap water samples, indicating that the method is very suitable for measuring celecoxib in real samples with a recovery in the range of 90.3-96.8% with a relative standard deviation lower than 5.1 %. The important advantages of the method are simple and inexpensive procedure, low desorption solvent and sorbent consumption, and without the need for sophisticated and expensive instruments.