Stability study of morphine in dried post-mortem blood spots for forensic purposes

In forensic cases, dried blood spot (DBS) collection and analysis for the detection of substances of abuse can give important information about the psycho-physical condition of the victim or the aggressor at the time of the crime. Nevertheless, morphine determination and stability in DBSs realized with post-mortem blood has not yet been sufficiently investigated. Therefore, a sensitive and specific gas chromatography with mass spectrometry method for morphine identification and quantification in post- mortem DBSs was developed and validated. Different media (paper and fabric) for blood deposition were studied, as media commonly investigated for forensic purposes, and sample preparation was specifically optimized in terms of recovery and repeatability. In order to properly consider DBS composition during criminal investigations, the stability of morphine content in DBSs was investigated. A stability study carried out on post-mortem DBSs stored at ambient temperature, showed that morphine concentration resulted almost constant within 100 days; after one year, a moderate decrease that does not compromise morphine analytical determination (36% and 9% for DBSs on paper and fabric, respectively) was observed.