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«“√ “√ √“™∫— ≥±‘ µ¬ ∂“π ªï ∑’Ë Û ©∫— ∫∑’Ë Ù µ.§.-∏.§. ÚıÙ¯ 1129 Scientific Instrumentation in Research Scientific Instrumentation in Research ∑»æ√ «ß»å √— µπå * √“™∫— ≥±‘ µ¬ ”π— °«‘ ∑¬“»“ µ√å √“™∫— ≥±‘ µ¬ ∂“π The introduction of modern scientific instrumentation has had a dramatic effect on research and development in all scientific disciplines in academic as well as in industrial establishments. The Beckman Model G pH meter was the first instrument to use electronics as a primary tool for chemical investigation, a harbinger of the revolution in instrumentation that was to follow. The Beckman DU UV-vis spectrometer followed the Beckman Model G, introducing the vast potential spectrophotometric techniques to routine chemistry. Before the introduction of the Beckman DU, chemical instrumentation was specialized equipment in the hands of a few labs that were either exceptionally skilled in optics and engineering or unusually well-funded. The DU made analytical instrumental analysis available to scientists not interested in or capable of making their own instruments at an affordable price. The result was a standardization of techniques and measurement that can be extrapolated across all disciplines of chemistry. For the first time, any lab could directly compare results with literature or other labs without having to replicate whatever homemade instrument was used originally. The introduction of almost every modern spectrometers can be traced back to the introduction of the DU, which in turn can be traced to the Model G pH meter. The introduction of modern chemical instrumentation made the stunningly powerful tools of electronic and electro-optics analyses available to almost every chemist, dramatically increasing the pace, breadth, and ease of chemical investigation. As an organic chemist, today I shall focus my lecture on the application of instrumentation on chemical research. To appreciate the role of scientific instrumentation in scientific research, I shall briefly touch on spectroscopy. Spectroscopy is a type of chemical analysis done by shining light on a sample to determine what is inside. Chemists commonly measure the absorbance, how much light is absorbed by the sample, or the transmittance, how much light passes through the sample. In a chemical analysis, many different kinds (wavelengths or energies) of light (a spectrum) are shone through a sample. Some of the light is absorbed. By knowing what wavelengths of light are absorbed by the sample, we know what is inside. But, if we are looking for a specific molecule or characteristic and shine the wrong wavelengths of light through a sample, no matter how much light we put through, we will never learn anything about the sample. Because different molecules and characteristics of molecules absorb at different energies of light, there is a need for different forms of spectroscopy. Each different form of spectroscopy uses a different part of the electromagnetic spectrum, shown below, to investigate specific characteristics of a sample. For example, infrared spectroscopy (IR) is used to investigate how the molecules in a sample vibrate, while ultraviolet spectroscopy (UV) is used to investigate how certain chemical bonds in a molecule are arranged. Remember, IR spectroscopy can not be used to investigate the information that UV provides and vice-versa. * ∫∑∫√√¬“¬æ‘ ‡»…‡√◊Ë Õß Scientific Instrumentation in Research (‡§√◊Ë Õß¡◊ Õ«‘ ∑¬“»“ µ√å °— ∫ß“π«‘ ®— ¬) ¡‡¥Á ®æ√–‡®â “≈Ÿ °‡∏Õ ‡®â “øÑ “®ÿ Ó¿√≥«≈— ¬≈— °…≥å Õ— §√√“™°ÿ ¡“√’ ∑√ß∫√√¬“¬„π°“√‡ªî ¥ — ¡¡π“∑“ß«‘ ™“°“√ ‡√◊Ë Õß °“√„™â ·≈–¥Ÿ ·≈‡§√◊Ë Õß¡◊ Õ«‘ ∑¬“»“ µ√å ∑’Ë ´— ∫´â Õπ√“§“·æß ´÷Ë ß ”π— °«‘ ∑¬“»“ µ√å ·Àà ß√“™∫— ≥±‘ µ¬ ∂“π ”π— °ß“π§≥–°√√¡°“√«‘ ®— ¬·Àà ß™“µ‘ ·≈– ¡“§¡∏𓧓√°√–¥Ÿ °·≈–‡π◊È Õ‡¬◊Ë Õª√–‡∑»‰∑¬ „πæ√–Õÿ ª∂— ¡¿å ¡‡¥Á ®æ√–‡®â “æ’Ë π“߇∏Õ ‡®â “øÑ “°— ≈¬“≥‘ «— ≤π“ °√¡À≈«ß π√“∏‘ «“ √“™π§√‘ π∑√å √à «¡°— π®— ¥¢÷È π ≥ ‚√ß·√¡¡‘ √“‡§‘ ≈ ·°√π¥å §Õπ‡«π™—Ë π °√ÿ ߇∑æœ ‡¡◊Ë Õ«— π∑’Ë Ò˜-Ò¯ ‘ ßÀ“§¡ æ.». ÚıÙ¯

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