Embodiments of the present invention relate to detector structures for use in a micro gas analyzer, preferably in a differential setup. The detector structures may comprise one or more detector types, such as photo-ionization (PID), electron capture (ECD), ion mobility (IMS), differential mobility (DMS), ion-trap mass spectrometer (ITMS), in which all are provided with ions and electrons from one vacuum ultra violet (VUV) source. This source may also provide ions for ion-based gas pumps.