Wood-derived cellulose aerogel decorated with high Zr-MOF loading for simple and efficient extraction of etomidate analogs from urine and e-cigarette samples.

Etomidate and its analogs can produce euphoria and addiction, and their recent abuse has led to an increasing number of poisoning and fatal cases. Thus, they are classified as controlled psychotropic drugs. This work proposed small-sized wood aerogel-supported zirconium metal-organic framework (UiO-66) particles for the extraction of trace etomidate and its analogs from urine and e-cigarette samples. Owing to the removal of lignin and hemicellulose, the delignified wood aerogel exhibited enhanced internal pore structures and exposed functional groups, which facilitated the immobilization of more UiO-66 crystals and achieved a high loading efficiency of 61.3 %. The lightweight UiO-66/wood aerogel composite enables facile separation, avoiding UiO-66 powder leakage while retaining its adsorption capacity. The composite was mechanically stable and kept commendable reusability over nine consecutive cycles. Benefiting from its high specific surface area and multiple chemical interactions with target drugs, the extraction method achieved enrichment factors of 22.9-30.0. Key factors influencing extraction-including solution pH, extraction time, the type and volume of desorption solvent, and desorption time-were investigated. Under the optimal conditions, the UiO-66/wood aerogel-based micro-solid phase extraction coupled with GC-MS method showed wide linear ranges and good precision (1.1%-3.2% for intra-day; 3.4%-5.1% for inter-day). The limits of detection and quantification were in the range of 0.02-0.04 μg/L and 0.05-0.1 μg/L, respectively. The recoveries for the urine and e-cigarette oil samples ranged from 86.2%-110.2% and 80.1%-107.9%, respectively. This method is eco-friendly, simple, and sensitive for the determination of new psychotropic drugs in clinical and forensic applications.