Development, Optimization, and Application of Molecularly Imprinted Polymers-Solid Phase Extraction Procedure for the Analysis of Selected Pharmaceuticals in Vegetable Samples

Abstract

The growing presence of pharmaceutical residues in the environment has aroused worries about their possible buildup and accumulation in the food chain, particularly in edible plants. Conventional analytical methods frequently fail to selectively isolate and quantify trace amounts of these chemicals in complex plant matrices. This study introduces an optimized methodology for the analysis of pharmaceuticals in vegetables. The enhanced molecularly imprinted solid phase extraction (MISPE) approach investigates the extraction of selected pharmaceuticals, fenoprofen, naproxen, diclofenac, ibuprofen, and gemfibrozil in vegetables. The extracted compounds were identified both qualitatively and quantitatively using a high-performance liquid phase chromatographic (HPLC) system coupled with a photodiode array detector. This method was effectively implemented on vegetable samples collected from Durban, South Africa (SA), including lettuce, carrot, cucumber, and green pepper. The recovery rates varied from 45% to 103%, with relative standard deviation (%RSD) ranging from 0.9% to 13%. Fenoprofen was the most prevalent compound, exhibiting high concentrations in pepper and cucumber, with maximum concentrations of 6.44 and 4.99 mg kg⁻¹, respectively. The health index (HI) values for the vegetables ranged from 0.27 to 1.25. The pepper sample (1.25) surpassed the HI threshold value of 1, reflecting the health indicator risk associated with the consumption of peppers available within the area. The health risk assessment (HRI) values spanned from 0.00012 to 0.83 for both adults and children, suggesting no health risk associated with the consumption of these vegetables.