There are many types of food, a long supply chain, and difficulty in safety supervision. Detection technology is an important means to ensure food safety. However, existing detection technologies face challenges in food safety detection, such as poor specificity of key materials, long sample pre-treatment time, low enrichment efficiency, and low selectivity of detection core components such as mass spectrometry ion sources, which result in real-time analysis of food samples. Faced with challenges, our chief expert team led by Zhang Feng has achieved a series of technological breakthroughs in the research direction of key materials, core components, and innovative methods for food safety testing.
In terms of key material research and development, the team has explored the specific adsorption mechanism of pre-treatment materials on harmful substances in food, and developed a series of highly specific adsorption micro nano structure pre-treatment materials. The detection of target substances at trace/ultra trace levels requires pre-treatment for enrichment and purification, but existing materials have limited enrichment capabilities and insufficient specificity, resulting in detection sensitivity not meeting the detection requirements. Starting from the molecular structure, the team analyzed the specific adsorption mechanism of pre-treatment materials on harmful substances in food, introduced functional groups such as urea, and prepared a series of covalent organic framework materials with chemical bond regulation（ Fe3O4@ETTA-PPDI Fe3O4@TAPB-BTT and Fe3O4@TAPM-PPDI And coated on the surface of magnetic nanoparticles. Used for the enrichment and purification of harmful substances such as aflatoxins, fluoroquinolone veterinary drugs, and phenylurea herbicides in food, the pre-treatment time is shortened from a few hours to a few minutes. Compared with national standard methods, the detection sensitivity is increased by more than a hundred times, breaking through the technical difficulties of poor material specificity leading to cumbersome pre-treatment processes and low detection sensitivity, which are difficult to meet the detection requirements.
In the research and development direction of core components, the team will separate new materials and integrate them with mass spectrometry ion sources to develop highly selective mass spectrometry ion source components and real-time mass spectrometry rapid detection methods. At present, the commonly used colloidal gold test strips for on-site rapid inspection are small and portable, but their qualitative and quantitative accuracy is relatively low. Mass spectrometry has the advantage of high accuracy, but the equipment is bulky and requires lengthy sample pretreatment and chromatographic separation processes, making it difficult to use for on-site rapid detection. The team has broken through the bottleneck of existing real-time mass spectrometry ion sources only having ionization function, and introduced a series of separation material modification technologies into mass spectrometry ion sources, enabling ion sources to have separation function. It can purify complex sample matrices such as food while ionizing target substances, eliminating the cumbersome chromatographic separation before food mass spectrometry analysis, and developing a series of separation ionization integrated real-time mass spectrometry ion sources. If the developed molecularly imprinted material is coupled with a conductive substrate to develop a new mass spectrometry ion source (as shown in Figure 2), a real-time mass spectrometry rapid detection method is established for the detection of carbamate esters in food, with a detection speed of ≤ 40 seconds and a quantitative limit of up to 0.5 μ Compared with the national standard method, the detection speed of g/kg has been reduced from tens of minutes to tens of seconds, and the sensitivity has been improved by nearly 20 times, solving the technical problem of insufficient accuracy in on-site food safety detection technology.
In 2023, the team achieved a series of breakthroughs in innovative food safety testing technology, developing 8 new purification and enrichment materials and 3 new mass spectrometry ion source elements; Apply for 15 invention patents; 14 authorized invention patents; Obtained 2 software copyrights; Developed 9 food safety standards and published 21 articles in domestic and foreign journals, including 8 SCI Zone 1 TOP articles.