Comparative study of field desorption and secondary ion mass spectra for antibiotics

Nonvolatile and thermolabile antibiotics are investigated both by field desorption and by secondary ion mass spectrometry (SIMS). It has been successfully demonstrated that these two methods are complementary in obtaining informations about molecular weight and structure. Although FD is most widely used for the investigation of nonvolatile biologically active compounds, there are some compounds of which FD can not provide reliable information. SIMS is successfully applied to obtain structural information of these compounds. SIMS spectra frequently depend on the surface conditions of sample holder materials.