Analysis of synthetic opioids in postmortem blood, vitreous humor, and brain tissue

In the United States, the use of new synthetic opioids (e.g. fentanyl and derivatives) has become an increasing health issue with thousands of overdose deaths being observed since 2013. With the high mortality rate associated with these substances, postmortem analyses and interpretation of synthetic opioids has become extremely important. However, due to the novelty of these compounds, the available data is limited and provides challenges to toxicologists. The focus of this project was to examine the postmortem distribution of new synthetic opioids in blood, vitreous humor, and brain tissue. New methods were developed and validated to quantify 13 synthetic opioids in vitreous humor and 12 synthetic opioids in brain by liquid chromatography-mass spectrometry (LC-MSMS), achieving a limit of quantification of 0.1 ng/mL or ng/g. Fifty-eight authentic case samples obtained from the New York City Office of the Chief Medical Examiner (NYC-OCME) were analyzed to assess the distribution and detectability of synthetic opioids in these postmortem samples. Of the synthetic opioids included in the method, six synthetic opioids (4-ANPP, acetylfentanyl, fentanyl, furanylfentanyl, norfentanyl, U-47700) were detected in the authentic cases. Concentrations for most analytes were within the 0.1 to 100 ng/mL or ng/g calibration range across all three matrices, with only concentrations from acetylfentanyl and U-47700 exceeding 100 ng/mL or ng/g. Through the case analyses, vitreous humor and brain demonstrated to be viable alternatives to blood when performing postmortem analyses of synthetic opioids. Brain exhibited a higher detectability for most analytes when compared to blood and vitreous humor