Multiparameter optimization of magnetite solid-phase microextraction for preconcentration of diclofenac and determination by UV–Vis Spectrophotometry

In this work, a clean and simple magnetic solid-phase microextraction based on L-arginine modified magnetic dialdehyde starch nanocomposite was developed for the preconcentration and determination of diclofenac in biological samples by UV–Vis Spectrophotometry. A Plackett–Burman experimental design was used to evaluate the influence of effective parameters. Significant parameters were further optimized by Central Composite Design. Sample volume, pH and salting effect had a main effect on extraction of diclofenac by the proposed method. Under the optimized conditions, the detection limit (3 S b , n = 7) was found to be 0.039 µg ml −1 . The calibration curve showed dynamic linear 0.05–10 µg ml −1 with correlation coefficients ( R 2 ) of 0.987. The enrichment factor was found to be 148. The proposed method showed good results for preconcentration and determination of diclofenac in serum and pharmaceutical samples.