Rapid screening of illegal additives in functional food using desorption electrospray ionization mass spectrometry imaging.

Compounds such as Sildenafil, which bring potential health risks to consumers, have been illegally added to functional food. The public security department hopes to quickly screen for illegal additives. The quantity of seized samples is often large and their compositions are unknown; it is necessary to screen the unknown samples qualitatively and sometimes quantitatively. In this paper, a new method for rapid screening of 39 common illegal additives in six categories of functional food based on DESI-MSI technology is proposed, and the DESI-MSI library is established, which can be used for exclusive and sensitive qualitative confirmation of suspicious samples. A new carrier material that can be used for rapid qualitative detection of solid sample is discovered. The samples require simple or even no pretreatment to carry out high-resolution imaging through the imaging function of DESI-MSI. The imaging results are clear and intuitive, and can achieve fast and high-throughput qualitative identification of illegally added compounds. This method has good linearity, accuracy, precision, and little effect of matrix, so it can roughly quantify the illegal additives in functional products. Twenty-one batches of unknown samples were detected by DESI-MSI, and the positive results were confirmed by LC-MS/MS (QQQ). The results showed that the DESI-MSI method was effective and reliable. DESI-MSI with self-made database is a promising method for rapid screening of illegal additives in functional food, which can be widely used in grass-roots police stations.