Complementary Separation of Novel Synthetic Opioids

The
escalating prevalence and diversity of fentanyl analogues
poses
an immediate concern for the global community. Fentanyl and its analogues
are the primary contributors to both fatal and nonfatal overdoses
in the United States. The most recent instances of fentanyl-related
overdoses have been attributed to the illicit production of fentanyl,
characterized by its exceptionally potent nature. In this study, we
present a high-throughput mass spectrometry based method for effective
screening of fentanyl analogues with focus on the isomeric separation
using commercially available platforms combining liquid chromatography,
trapped ion mobility spectrometry, and tandem mass spectrometry (LC-TIMS-q-TOF
MS/MS). The proposed analysis allows for effective separation and
identification of 250 synthetic opioids based on the isotopic pattern,
retention time, mobility profile, and MS/MS pattern. Our approach
capitalizes on the advancements incorporating parallel accumulation
in the mobility trap followed by sequential fragmentation (PASEF)
using collision-induced dissociation on the liquid chromatography
time scale. While a single chromatography band is commonly observed
for single isomeric analogues, a dual mobility band profile attributed
to two protonation sites is commonly observed for most fentanyl analogues.
Reference mobility values are reported from single standards with
0.2% RSD collected at high resolution (RIMS ≈ 80–120).
The added mobility separation resulted in the separation of isomeric
compounds without compromising the sensitivity of the LC-q-TOF MS/MS
analysis; that is, a good linear dynamic and (R2 > 0.98)
and low limits of detection (LOD) in the 0.08–4 ng/mL range
were observed for all synthetic analogues (∼100 analogues can
be observed with LOD < 1 ng/mL).