Modified dispersive solid-phase extraction of benzophenones and parabens from water samples using nutshell-derived biochars: development, validation and greenness assessment.

A simple, fast, and eco-friendly modified dispersive solid-phase extraction (dSPE) method was proposed for the determination of benzophenones and parabens in water samples using biochars derived from nutshells (walnut, hazelnut, peanut, and pistachio shells). Biosorbents were characterized by FTIR, SEM, and BET analyses. The extraction conditions, including sample pH, sorbent mass, extraction time, desorption solvent, volume of desorption solvent, and number of elution cycles, were optimized to achieve maximum efficiency. The optimized dSPE method showed satisfactory performance with recoveries, carried out by analyzing spiked water samples, ranging from 60 to 103% for benzophenones, and from 48 to 97% for parabens. Furthermore, the enrichment factors were achieved in the range of 120 - 258. The results of this study suggest that nutshell-derived biochars have significant potential in the dSPE method for determining target emerging contaminants in water samples. Additionally, the developed methodology was evaluated in terms of applicability and sustainability using the Blue Applicability Grade Index (BAGI), Analytical Greenness Metric for Samples Preparation (AGREEprep), and Sample Preparation Metric of Sustainability (SPMS), exhibiting excellent results confirmed the practicality and greenness of the proposed method.