Spatially offset Raman spectroscopy (SORS) is an important branch derived from conventional Raman spectroscopy. It has the characteristics to realize the concealed component identification covered by opaque and translucent media nondestructively and rapidly. This technology gradually plays an important role in basic and applied research of numerous areas. This paper focuses on the SORS potential application in food quality and safety inspection, and a SORS detection system has been setup. The ingredients of various concealed food additives have been identified by SORS and the optimum offset distance for detection has been obtained. Meanwhile, the identification effectiveness of the system for low-concentration additives in real foods has also been evaluated.
Carminic acid (CA) extracted from cochineal is widely used in food additives as a natural colorant, and its potential risk to human health makes its detection important. In this work, a layered doubled hydroxide (LDH)–luminol–H2O2 system-based chemiluminescence (CL) platform has been successfully applied for CA sensing. The principle detection consists of two steps: first, LDH adsorbs CA onto the surface via electrostatic attraction; second, CA quenches the CL of the LDH–luminol–H2O2 system via the synergistic effect of CL resonance energy transfer, reduction of reactive oxygen species, and occupation of positively charged centers of brucite-like layers. With this CL approach, 0.5 μM CA is detectable using a CL spectrometer, and the limit of detection is 0.03 μM. This CL system exhibited a linear response to CA in the concentration range from 0.5 to 10 μM. In addition, the practical application of the designed CL sensing system is evaluated with dried pork slice samples.
危险品化学品经营许可证（带存储）