A reflection type ion attachment mass spectrometry apparatus is provided with a metal ion generation region, an attachment region and a mass spectrometry region. A protective potential lower than any operating potential applied to the semiconductor device elements is applied to the conductive layer. These samples may be differentially amplified with weighted gains and then combined and compared to a threshold value to generate an LOS alarm signal. The method comprises: a) heating a composition, comprising diazepam to form a vapor; and, b) allowing the vapor to cool, thereby forming a condensation aerosol with less than 5% of the drug degradation products.