Application of Desorption Electrospray Ionization Mass Spectrometry Imaging Technology in Physical Evidence Detection of Lipstick Cosmetics

There were few researches on cosmetics in forensic science physical evidence detection at present, and the detection methods were mostly chromatography. The sample pre-processing was complicated and it was difficult to accurately identify. This article intended to take lipstick cosmetics as an example to propose a method of desorption electrospray ionization mass spectrometry imaging (DESI-MSI) detection suitable for the analysis of lipstick components. The 30 lipstick samples of different brands were tested. According to the mass charge ratio of quasi-molecular ions and fragment ions obtained in positive and negative ion modes, by comparing the differences in the components and mass spectrum data of different grades of lipsticks, a preliminary database of lipstick mass spectrometry information suitable for criminal technology was established. This method had good repeatability and strong qualitative ability. It could quickly and qualitatively detect the main components in lipstick without complex sample pretreatment. On one hand, the detection method could be applied to the authenticity of lipstick products, and on the other hand, it could compare and identify the lipstick residue evidence in actual cases, so as to provide ideas for characterizing suspects and determining the direction of investigation.