Forensic Analysis of Stains on Fabric Using Direct Analysis in Real‐time Ionization with High‐Resolution Accurate Mass‐Mass Spectrometry

A rapid technique using direct analysis in real ‐ time ( DART ) ambient ionization coupled to a high ‐ resolution accurate mass‐mass spectrometer ( HRAM ‐ MS ) was employed to analyze stains on an individual's pants suspected to have been involved in a violent crime. The victim was consuming chocolate ice cream at the time of the attack, and investigators recovered the suspect's pants exhibiting splatter stains. Liquid chromatography with mass spectral detection ( LC ‐ MS ) and stereoscopic light microscopy ( SLM ) were also utilized in this analysis. It was determined that the stains on the pants contained theobromine and caffeine, known components of chocolate. A shard from the ceramic bowl that contained the victim's ice cream and a control chocolate ice cream sample were also found to contain caffeine and theobromine. The use of DART ‐ HRAM ‐ MS was useful in this case due to its rapid analysis capability and because of the limited amount of sample present as a stain.