Direct analysis in real time mass spectrometry: Observations of helium, nitrogen and argon as ionisation gas for the detection of small molecules using a single quadrupole instrument.

All the target analytes were detected using DART-MS with helium, nitrogen or argon as the ionisation gas. Whilst helium provides the highest sensitivity, nitrogen produced reasonable limits of detection and had good linearity across the concentration range explored, suggesting it provides a greener and cheaper alternative to helium.