Thermal-fluid coupling green capture device coupling with Surface-Enhanced Raman Scattering for integrated scheme with rapid separation, enrichment and detection of multi-source formaldehyde in milk

Abstract

In milk and milk products, the matrix is complex and the interfering components are large, so it is difficult to separate and enrich formaldehyde. In this study, combined with Surface-Enhanced Raman Scattering (SERS) technology, the self-developed green capture device was used to realize the integration of separation, enrichment and detection of formaldehyde. Firstly, we use fluid dynamics to simulate the heat-fluid coupling working mechanism of the enrichment chemical mechanical device. By exploring the steady-state and transient changes of separation and enrichment gas flow under different working conditions, we designed a purge and separation device with small dead volume and high separation efficiency. We further optimized the purge air velocity and heating voltage to increase sample recovery and shorten the separation and enrichment time of the target. As a result, we have realized the application of green and efficient pre-treatment, which is rapid and green. Finally, we used derivatization strategy to enhance the Raman scattering and combined with colloidal gold nanoparticles (AuNPs) to realize SERS analysis. According to this method, we detected formaldehyde in boxed milk, milk powder and raw milk. Thus, we realized a rapid detection method of formaldehyde in milk from various sources, including exogenous and endogenous formaldehyde.