Novel psychoactive substances (NPS) have created a challenge for toxicology laboratories. New NPS are constantly disappearing as fast as they emerge, making it difficult to stay on top of which compounds are necessary to add to laboratory testing scopes.
The development and optimization of liquid chromatography (LC) separations is time-consuming and costly, often requiring several steps, including literature research, column selection, method scouting, method development, and method optimization. To alleviate the burden of sacrificing instrument-uptime, labor, and materials, an instrument-free software modeling tool was developed to include a comprehensive drugs of abuse (DoA) library.
Methods for NPS compounds were successfully developed in under ten minutes per method using this online chromatogram modeling tool. To verify the ability of the modeler to develop methods for NPS, three methods were developed and optimized using the chromatogram modeler for the following NPS subclasses: 1) synthetic opioids and toxic adulterants, 2) designer benzodiazepines, and 3) stimulants and synthetic cannabinoids. All methods utilized a Raptor Biphenyl 100 x 2.1, 2.7 μm column with a MPA of water and MPB of methanol, both acidified with 0.1% formic acid. The flow rate was 0.6 mL/min, and the column temperature was 40°C. The developed methods were transferred to an LC-MS/MS system and the experimental results were compared with the modeler.
The acceptance criteria for retention time agreement between experimental and modeled values was set at +/-15 seconds, chosen to represent a typical MRM window. All analytes in all three methods fell within this window, as well as maintaining elution order and resolution.
This online chromatogram modeling tool helps users obtain optimized separations while maintaining critical pair resolution by adjusting parameters, such as column dimension, mobile phase, gradient programs, and more, for almost 300 compounds, including the 38 newly added NPS drugs.
