•Identification of a nonoxynol mixture in vaginal fluid and condoms’ residues.•Detection of a nonoxynol mixture in vaginal samples collected 8 h after intercourse was achieved.•Different sample preparation and instrument setting methods were explored.In this study we demonstrate the use of Direct Analysis in Real Time Mass Spectrometry (DART) as a powerful tool for detection of nonoxynol in vaginal fluid post contact with a condom, enabling rapid tracing and added evidences in sexual assault crimes. Vaginal fluid was sampled using cotton swabs and glass rods and measured directly with DART. Sample preparation using water, hexane, methanol, and dichloromethane extraction, was explored for comparison and optimization of signals. Nonoxynol was detected up to eight hours after sampling. Optimal sampling conditions and mass spectrometry parameters are reported and discussed.Download high-res image (135KB)Download full-size image

The root bark of Cassia sieberiana was analyzed using direct analysis in real time mass spectrometry, and a main flavonoid component with an [M + H]+ mass of 275 was identified. The flavonoid, epiafzelechin, was isolated and fully characterized with the concerted use of NMR spectroscopy, circular dichroism, and optical rotation. Electronic circular dichroism and optical rotation TDDFT calculations were also performed, and their agreement with the experimental results confirmed the enantiomeric identity of the isolated natural product. The antioxidant activity of the compound was also investigated.