E-cigarette sample preparation. In experiments involving artificial actuation of e-cigarettes, ELF BAR devices were filled with a diverse range of commercially available e-liquids. ELF BARs were disassembled to expose adsorbent sponge and wicking material components. These were cleaned with methanol and dried before adding fresh e-liquid, 2 mL for all experiments/e-liquid flavors. For SCcontaining e-cigarettes, e-liquid was prepared at 1.5 mg/mL with either MDBM-4en-PINACA or MDMB-BINACA, where 300 μL 10 mg/mL SC in ethanol was mixed with 1700 μL eliquid. In addition to experiments performed using modified elf bars, a rage of commercially available sealed vapes were used to construct our predicative model for SC-detection in deposited e-liquid.