Atmospheric pressure field desorption (APFD) mass spectrometry (MS) has recently been introduced as a new variant of field desorption (FD) mass spectrometry. The development aimed at providing the basic characteristics of FD-MS in combination with instruments equipped with an atmospheric pressure (AP) interface. Hitherto, APFD has been demonstrated to yield both positive and negative even electron ions of highly polar or ionic compounds as well as to enable the generation of positive …