Discovering an unexpected compound and measuring it routinely are separate laboratory tasks. In a fish-tissue study, investigators used different mass spectrometry workflows for the two jobs.
High-resolution screening found a peak that shared nordiazepam’s precursor mass but eluted later and fragmented differently. Comparison with a reference standard supported its identification as BP-271. The researchers also identified BP-246 and added both compounds to a targeted method alongside diazepam and three established metabolites.
The team calibrated the method in a fish-tissue matrix and reported linearity from 0.2 to 10 micrograms per kilogram. It then applied the panel to ten market fish samples already selected as diazepam-positive. That application demonstrated what the expanded panel could measure in those specimens. It does not estimate prevalence in the market or validate the method for human specimens.
Study of diazepam transformation products in freshwater fish (full text) · DOI