Rotary Microdevice for Aldehyde Detection via Centrifugal Separation

The patent employs disposable DNPH-coated silica gel cartridges instead of expensive commercial DNPH cartridges. The microdevice uses inexpensive, single-use cartridges that can be discarded after one analysis, eliminating the need for costly reusable cartridges while maintaining derivatization effectiveness. This resolves the contradiction by providing HPLC-level detection capability through a simplified, disposable system.

The patent extracts and integrates only the essential functions needed for carbonyl detection into a compact microdevice: sample injection, DNPH derivatization, and TLC separation. By removing unnecessary components of conventional HPLC systems and focusing on the core detection mechanism, the device achieves high sensitivity without the complexity of full HPLC instrumentation.

The patent introduces an absorption pad as an intermediary component between the eluent reservoir and the TLC plate. This absorption pad uniformly distributes the eluent across the TLC plate surface through capillary action, ensuring even deployment without requiring complex mechanical systems. The intermediary absorbs and redistributes the eluent, solving the uniformity problem while keeping the device simple.

The patent utilizes capillary hydraulic action through the absorption pad to achieve uniform eluent deployment. By leveraging the natural capillary forces in the porous absorption pad material, the system distributes eluent evenly across the TLC plate without requiring pumps, pressure systems, or complex mechanical deployment mechanisms, thus maintaining low device complexity while improving deployment uniformity.

The patent merges the derivatization function and separation function into a single integrated microdevice. The DNPH-coated silica gel cartridge performs both sample derivatization and serves as the stationary phase for TLC separation. By combining what would traditionally require separate pre-processing and analysis devices into one unit, the system maintains detection accuracy while eliminating the need for separate pre-processing equipment and reducing operational steps.

The DNPH-coated silica gel cartridge serves multiple functions simultaneously: it acts as the derivatization reagent source, the reaction chamber, and the TLC stationary phase. This multi-functional design eliminates the need for separate pre-processing devices and reduces the number of operational steps while maintaining the accuracy required for carbonyl compound detection.