ZIF-8 modified Citrus reticulata peel carbon aerogel as solid-phase microextraction coating for the determination of organochlorine pesticides.

A novel CRPCA@ZIF-8 biomass composite was synthesized by in situ growth of zeolite imidazoline frameworks on the Citrus reticulata peel carbon aerogel (CRPCA) surface to enhance the adsorption capacity. CRPCA@ZIF-8 was employed as a headspace solid-phase microextraction (HS-SPME) coating in conjunction with gas chromatography (GC) for detecting 12 organochlorine pesticides (OCPs). The effects of different adsorption and desorption conditions on the extraction efficiency were investigated. Under optimum conditions, the method demonstrated excellent linearity of 0.02 to 5 ng g^-1 (r² ≥ 0.996), low detection limits (0.002-0.043 ng g^-1), good repeatability (one fiber, 3.6-8.7%; fiber to fiber, 4.6-9.6%), and outstanding fiber durability over 100 cycles. The reliability of the method was validated by evaluating the recovery of spiked onion, cucumber, and pear samples, which ranged from 85.1% to 114.5%. This work provides a new idea for the treatment of agricultural wastes while developing a sensitive, accurate, and environmentally friendly detection method for trace OCPs. In addition, this novel SPME coating has potential for pre-treatment processes and pollutant adsorption.