Source: SDBSWeb : http://riodb01.ibase.aist.go.jp/sdbs/ (National Institute of Advanced Industrial Science and Technology of Japan, 22 August 2008) Chlorinated compounds show an M+2 peak that is 1/3 as large as the M+ peak. Note also that halogens are easily lost during mass spectrometry. If you subtract the mass of the halogen from the molecular ion mass, you will often find a peak that corresponds to the remainder of the structure. Problem MS4. Draw one possible structure for the compound in each of the following mass spectra. Source: SDBSWeb : http://riodb01.ibase.aist.go.jp/sdbs/ (National Institute of Advanced Industrial Science and Technology of Japan, 25 August 2008) Problem MS5. In the following mass spectrum, more than one halogen atom is present. What is a possible structure of the compound? Show why this pattern of molecular ions is observed. Source: SDBSWeb : http://riodb01.ibase.aist.go.jp/sdbs/ (National Institute of Advanced Industrial Science and Technology of Japan, 25 August 2008) Contributor Chris P Schaller, Ph.D. , (College of Saint Benedict / Saint John's University)