What is FTIR Spectroscopy? – Technology Introduction – METTLER TOLEDO - EN — Transcript

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1. 0:03[music]
2. 0:05>> Fourier transform infrared spectroscopy,
3. 0:08or FTIR, is an analytical technology
4. 0:11used in industry and academic
5. 0:13laboratories to understand the structure
6. 0:15of molecules and the composition of
7. 0:17molecular mixtures.
8. 0:19FTIR spectroscopy uses modulated
9. 0:22mid-infrared energy to interrogate a
10. 0:24sample.
11. 0:26The infrared light is absorbed at
12. 0:28specific frequencies directly related to
13. 0:30the atom-to-atom vibrational bond
14. 0:32energies in the molecule.
15. 0:34When the bond energy of the vibration
16. 0:36and the energy of the mid-infrared light
17. 0:38are equivalent, the bond can absorb that
18. 0:41energy.
19. 0:42Different bonds in a molecule vibrate at
20. 0:45different energies, and therefore absorb
21. 0:47different wavelengths of the IR
22. 0:49radiation.
23. 0:50The position or frequency and intensity
24. 0:53of these individual absorption bands
25. 0:55contribute to the overall spectrum,
26. 0:57creating a characteristic fingerprint of
27. 0:59the molecule.
28. 1:00Since FTIR spectroscopy produces signals
29. 1:03that are specific to the type of
30. 1:04molecular bonds or functional groups, it
31. 1:07is the ideal tool to measure the making
32. 1:09and breaking of chemical bonds during
33. 1:11reaction.
34. 1:13Coupling FTIR spectroscopy with
35. 1:15attenuated total reflectance, or ATR,
36. 1:18increases the utility of this technology
37. 1:20by providing a means to monitor
38. 1:22reactions in situ and in real time.
39. 1:26Measurements via ATR-FTIR
40. 1:28eliminate the need to manually sample
41. 1:30the reaction for offline analysis,
42. 1:33making it possible to determine, in real
43. 1:35time, key reaction characteristics, such
44. 1:38as initiation,
45. 1:40endpoint, reactive intermediates,
46. 1:43kinetics, and mechanistic information.
47. 1:46FTIR spectroscopy is fundamentally a
48. 1:48qualitative or relative measurement
49. 1:50technology,
50. 1:52but can also produce quantitative
51. 1:53measurements of important reaction
52. 1:55components. FTIR follows the
53. 1:57Beer-Lambert law, A = ABC.
54. 2:01Where the molar absorptivity, A, and the
55. 2:04path [music] length, B, are essentially
56. 2:06fixed and therefore constant.
57. 2:09So, the absorbance that a vibrational
58. 2:11frequency for a specific bond is
59. 2:13directly proportional to the number of
60. 2:15this specific bond or concentration.
61. 2:18Once calibrated, much like that for
62. 2:20HPLC, each measurement by the FTIR
63. 2:23instrument will be quantitative for the
64. 2:25reaction components it was calibrated to
65. 2:27measure.
66. 2:28Now, real-time quantitative information
67. 2:31can be obtained throughout the duration
68. 2:32of the reaction,
69. 2:34which can be used as control variables
70. 2:36for conditions such as add the next
71. 2:39reagent, cool, or heat, and even end the
72. 2:42reaction.
73. 2:46For more information, go to mt.com/ftir.