A hand-powered whirligig-like centrifuge with hydrophobic monolithic spin column for on-site extraction and screening of benzodiazepines

In recent years, benzodiazepines (BZDs), which are central nervous system depressants, have been abused and used illegally in crimes. Monitoring BZDs is imperative, and rapid on-site screening plays a key role in this monitoring due to the drugs' rapid metabolism. The matrix complexity of the real samples and the low concentration of BZDs pose significant challenges to on-site screening for BZDs using the existing lateral flow rapid screening card. Achieving rapid and accurate on-site screening necessitates the development of an efficient on-site sample preparation method. To this end, a novel hand-powered whirligig-like centrifuge was designed and manufactured through 3D printing. This centrifuge operates at a maximum speed of 5500 rpm (1400 g) and an average speed of 4500 rpm (1000 g). Furthermore, according to the properties of BZDs and the performance of the hand-powered whirligig-like centrifuge, the hydrophobic poly(BMA-co-EDMA) monolithic spin column was specially prepared for the extraction of trace BZDs. Thus, a spin column solid-phase extraction (SC-SPE) method based on the hand-powered whirligig-like centrifuge with the hydrophobic monolithic spin column was proposed for on-site extraction of BZDs. Under the conditions optimized with the assistance of HPLC, the on-site extraction and screening of trace BZDs in diverse samples was achieved. This work provides a feasible tool to realize the on-site sample preparation with a power-free hand-powered centrifuge, and facilitates the attainment of rapid and accurate on-site screening results, which are instrumental for specialized applications in on-site settings, remote regions, or underdeveloped areas.