Dispersive micro-solid phase extraction using alginate graphene oxide for the de-termination of selected non-steroidal anti-infl-ammatory drugs from water samples / Mohammad Salim Tabish Chaman Ali

The aim of this study was to synthesize alginate incorporated graphene oxide (Alg/GO) for the extraction of selected non-steroidal anti-inflammatory drugs (NSAIDs) using dispersive micro-solid phase extraction (D-u-SPE) technique. The effects of GO and Alg amounts on the performance of the composite beads were optimized. The sorbent Alg/GO (1.0:0.3 w/v %) was characterized using scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy and Brunauer- Emmett-Teller (BET). FTIR results of Alg/GO beads showed intermolecular hydrogen bonds, n-n stacking and electrostatic interactions within the Alg/GO matrix. BET linear plot of adsorption/desorption isotherms showed that Alg/GO relates to the type IV mesoporous materials with a hysteresis loop of type H3. SEM analysis of Alg/GO beads revealed homogenous pores on the relatively rough surface of the sorbent. The synthesized material was utilized as a sorbent in D-u-SPE for extraction of three targeted analytes (ibuprofen, naproxen, and diclofenac) from water samples prior to analysis by high performance liquid chromatography-ultraviolet detector (HPLC-UV). Furthermore, eight most effective parameters of D-u-SPE technique were optimized using the prepared sorbent beads. The obtained optimum parameters are 0.15 g of mass of sorbent, sample pH 3,1000 rpm stirring speed, 30 min extraction time, 0 % (w/v) salt addition, isopropyl alcohol (IP A) as desorption solvent, 300 uL IP A as desorption solvent volume and 10 min desorption time. Under the optimized conditions, good linearity (r2 > 0.9993) over a concentration range 10-1000 ug L"1 and detection limits between 3.5 - 4.8 ug L"1 with a relative standard deviation of < 6 % were obtained. The proposed method also provided acceptable relative recoveries in the range of 95.6 -102.2 %. Alg/GO is found to be a potentially good alternative sorbent for the monitoring of pharmaceuticals in water samples using D-u-SPE technique.