Characterization of fentanyl HCl powder prior to and after systematic degradation

Abstract

Fentanyl HCl is of particular interest in forensic cases but there is a notable gap in literature regarding its analysis. This study utilized a multi-method approach to characterize fentanyl HCl powder, both fresh and following a forced degradation process. Using sensitive liquid chromatography-tandem mass spectrometry (LC-MS/ MS) and direct injection gas chromatography-mass spectrometry (GC-MS), five

Vapor detection and vapor pressure measurements of fentanyl and fentanyl hydrochloride salt at ambient temperatures

“…The predominant form of fentanyl identified in seized drugs is fentanyl hydrochloride salt, which makes detection of vapor more challenging. Although fentanyl hydrochloride salt has a lower vapor pressure (0.018 ppq v at 25 °C) than fentanyl free base (90 ppq v at 25 °C), trace amounts of free base are likely present with the salt due to impurities from synthesis or from degradation, 11 which would enhance the ability to detect fentanyl vapor. Detection of such low-volatile species can be facilitated by pre-concentrating the vapor on a filter on the order of seconds to minutes, which could also enable standoff detection.…”

“…In addition, degradation of fentanyl hydrochloride powder, such as by heat, has been shown to increase the quantity of fentanyl vapor in headspace samples. 11 Despite the low vapor pressure, when vapor was collected for 5 minutes, fentanyl hydrochloride salt was detected at 40 °C (104 °F, equivalent to ambient temperatures on a hot day or temperatures within a cargo container in the summer). Longer collection times could enable detection by AFT-MS at lower temperatures.…”

“…Thermal degradation of fentanyl hydrochloride (HCl) has been shown to increase the fentanyl vapor concentration in the headspace above the salt. 11 Ciesielski et al 11 observed minimal changes in the percent fentanyl composition in the degraded powder, yet they observed a significant increase in the headspace fentanyl vapor concentration above the degraded powder compared with the fresh powder. A possible explanation for this is that the some of the fentanyl hydrochloride was converted to the free base, which is anticipated to have a higher vapor pressure.…”