강민재 (동국대학교)

차상원 (동국대학교)

강민재 (동국대학교)

차상원 (동국대학교)

Ambient desorption ionization (ADI) enables the direct mass spectrometric (MS) analysis of raw sample materials without extensive preparation. Owing to this advantage, ADI-MS has been widely applied in chemical fingerprinting across diverse fields, including food analysis, environmental monitoring, and clinical research. In this study, we evaluated various ADI strategies for the direct analysis of fruiting vegetables, using paprika (Capsicum annuum L.) as a representative model due to its protective waxy cuticle and metabolite-rich flesh. Paprika contains a broad spectrum of compounds, including sugars, lipids, carotenoids, and flavonoids, making it a suitable matrix for assessing ADI performance. We comparatively examined three ADI techniques: paper spray ionization (PSI), imprinted paper spray ionization (iPSI), and leaf spray (LS). In the PSI method, water extracts of homogenized paprika flesh were applied to a triangular paper tip. In iPSI, a slice of paprika was pressed directly onto the paper tip using a hand press to transfer analytes. For LS, a triangular slice of raw paprika flesh served directly as the ionization substrate. The techniques were assessed based on signal intensity, repeatability, spectral fingerprinting, and spray stability.​