Abstract
The pervasive application of organophosphorus pesticides (OPPs) in agriculture underscores the critical need for sensitive and reliable analytical techniques to safeguard food safety. Addressing this challenge, this work presents a rigorous comparative evaluation of two engineered sorbents for dispersive micro-solid phase extraction (D-μ-SPE) prior to gas chromatography-mass spectrometry (GC-MS): Bimetallic Fe/Co-MIL-88A and a novel Bimetallic Fe/Co-MIL-88A-on-MIL-88B composite. While both sorbents demonstrated high and statistically comparable extraction efficiencies, the composite was selected for its exceptional reusability and sustained performance over five consecutive cycles. Leveraging a design of experiments (DoE) approach, key extraction parameters were optimized for both sorbents, achieving remarkable sensitivity and precision. The method demonstrates an impressive linear dynamic range (LDR) of 0.07-900 ng mL-1, with detection limits as low as 0.02-0.09 ng mL-1, alongside high enrichment factors (up to 67) and excellent reproducibility (RSDs 3.16-4.35 %). Analysis of vegetable and fruit juice samples yielded robust recoveries (93.5-103.6 %) with precision (RSDs 4.37-6.33 %), affirming the method's reliability for routine monitoring. This work not only advances analytical capabilities for OPP detection but also contributes significantly to food safety surveillance, ensuring enhanced consumer protection.
Keywords:
Commerial fruit juice samples; Comparative study; Dispersive micro-solid phase extraction; MOF on MOF composite; Organophosphorus pesticides; Vegetable samples.