LAUSR

The opioid crisis has led many providers to inquire about the capabilities of urine drug testing to detect contemporary compounds such as fentanyl and fentanyl analogs. However, current methods for clinical urine drug testing, including immunoassays and targeted liquid chromatography tandem mass spectrometry, are not designed to broadly screen for the variety of fentanyl analogs that may be encountered. In this proof-of-principle study we developed a precursor ion scan method to enable semi-targeted data acquisition for structurally related fentanyl analogs. Based on the knowledge that many analogs fragment to m/z=188 and m/z=105, data was acquired on all precursor ions 250-400 Da that fragmented to these product ions. Using a tandem mass spectrometer we analyzed 102 residual urine specimens, in which we identified fentanyl, acetylfentanyl and acrylfentanyl. In 30 contrived urine samples, the precursor ion scan was also able to identify furanylfentanyl, butryrlfentanyl, 4-fluroisobutrylfentanyl, and despropionylfentanyl with accuracy ranging from 83-100%.