Disclosed are methods and devices for analyzing non-volatile organics in exhaled breath and other aerosols using various diagnostic tools that enable rapid, low cost point of care assays for several diseases including respiratory tract diseases such as COVID-19. The disclosed methods and systems selectively capture non-volatile organics in exhaled breath and other aerosols in a packed bed column. The non-volatile organics are eluted and samples are analysis using diagnostic devices including MALDI-TOFMS. The disclosed systems and methods provide for a diagnostic test result in less than about 20 minutes and provides for autonomous operation with minimal human intervention.