Fabrication of a cellulose paper based rotating paper disc as sustainable extraction device for anesthetic drug analysis in postmortem blood

In the present work, a rotating paper disc (RPD) device is fabricated and applied for effective, facile, and high-throughput extraction of four anesthetic drugs (prilocaine, lidocaine, bupivacaine, and ropivacaine) from forensic postmortem blood. The RPD utilizes a low-cost, natural, and biodegradable cellulose-based sorbent that is impregnated with octanol to enhance amphiphilic interactions for effective drug extraction. Device fabrication involves placing a magnetic bar between the layers of octanol-supported cellulose, which allows direct immersion in diluted blood samples and its rotation in the magnetic field. The important parameters, such as pH, ionic strength, extraction/desorption rate, and time, were optimized systematically. Adsorption was optimized at 400 rpm for 30 min and then rapid back-extraction into 2 mL of ethyl acetate. The approach showed good linearity (0.1–5 μg mL⁻¹), good extraction efficiency (92–112 % recovery), low LOQs (0.05–0.09 μg mL⁻¹), and excellent intra-day/inter-day precision (3.5–13.4 %). The disposable RPD device eliminates carry-over between samples and supports high sample throughput (15 samples/h) at a low cost (∼$0.3/unit). The BAGI practicality score (75) and ComplexMoGAPI greenness score (80) validate the method's compliance with green and white analytical chemistry. Applied to forensic toxicology casework, the procedure successfully determined an anesthetic drug in actual postmortem blood samples, illustrating its potential for regular forensic and clinical toxicology uses. Considering its sustainability, low cost, and excellent sensitivity, the RPD-GC-MS strategy is an innovative approach in sample preparation.