This publication is a technical note to the white paper “Evolving Approaches and Technologies for Seized Drug Analysis” describing direct analysis in real time mass spectrometry (DART-MS).
This technical note to the white paper “Evolving Approaches and Technologies for Seized Drug Analysis” provides an in-depth description of direct analysis in real time (DART), a rapid noncontact ambient ionization source that was first described in 2005 and allows for the direct analysis of solid, liquid, or gas samples without extensive sample preparation. DART itself is only an ionization source and must be coupled with a mass spectrometer to detect the ionized species generated in the open-air gap between the DART source and the mass spectrometer inlet. DART ionization occurs based on gas phase reactions of electronic or vibronic excited-state species, typically helium or nitrogen, with atmospheric reagent molecules (such as water or solvent, and target analytes) through a process that is closely related to atmospheric pressure chemical ionization. DART is a soft ionization technique that provides easily interpreted mass spectra that are dominated by the formation of molecular ions or protonated/deprotonated molecules depending on the nature of the source gas, analyte, concentration, and ion source polarity. The ability to gather real-time results with little to no sample preparation makes ambient ionization mass spectrometry (MS) techniques such as DART-MS an attractive option for rapid screening of seized drug evidence.