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The Journal of the Royal Institute of Thailand Vol. 30 No. 4 Oct.-Dec. 2005 1130 Scientific Instrumentation in Research H 2 N O OH OH OH O HO OH OH OH HO OH OH OH OH OH O OH OH OH OH HO O OH OH H HO OH OH OH O OH OH OH HO HO O O O O OH OH OH HO OH O H OH OH HO HO OH OH OH N H O N H O HOH 2 C(CH 2 ) n n = 2 73 Four primary spectroscopic techniques have been in use since the early 1960s. They are nuclear magnetic resonance (NMR), infrared (IR), ultraviolet-visible (UV-VIS), and mass spectroscopy (MS) . All of these methods are used daily by most organic chemists. They require a minuscule amount of material and for the most part are nondestructive. The use of NMR, IR, UV-VIS, and MS can be replaced by another well-known tool, X-ray crystallography, but only for the analysis of well-formed crystals. Compounds with molecular weights of under 1,000 amu are excellent candidates for study by the methods of organic spectroscopy. In recent years, advances in NMR and MS instrumentation along with experimental strategies have even made it possible to tackle structural elucidation of very complex compounds. For example, the intricate structure of the natural product palytoxin structure as shown of molecular weight 2677 amu and molecular formula C 129 H 223 N 3 O 54 was proposed based on spectroscopic data. But the process of collecting the appropriate data, making unambiguous interpretations, and reweighing the data took some twenty years! To be successful in the task of organic structure analysis, especially when an exotic compound is in hand, requires several attributes. In addition to chemical common senses it is helpful to have experience Microwaves Radio Waves Infrared Visible Ultraviolet X-rays Gamma rays Energy