Herschel region

The NIR region of the electromagnetic spectrum is from 800 to 2500 nm. The segment from 1100 to 2500, known as the Herschel region, is the range most often used in the analysis of pharmaceutical products. In the NIR region, the radiation can penetrate compacted materials such as tablets, providing a vast amount of spectral information about the sample. 

The Herschel region of the NIR spectrum has been defined as 700-1000 nm, the region covered by sihcon-based detectors. 

NIR Technology Austraha 34 Clements Avenue Bankstown NSW 2200 Australia TEL 4-61 (0) 2 9790 6450 FAX 4-61 (0)2 9790 1552 EmaU nirtech zipworld.com.au URL http //www.lineart.zip. com.au/homepage.htm Near-infrared analyzers (Herschel region)... 

In 1800 Sir William Herschel found that a thermometer placed in the region beyond the red end of the solar spectrum (obtained by dispersing solar radiation with a prism) was heated even more than when placed in the visible portion Herschel had discovered infrared radiation. Around 1900 infrared (IR) absorption investigations of molecules began. 

Herschel Open Time Key Program Gas in Protoplanetary Systems 1 will obtain spectra of far-infrared atomic and molecular lines from over 240 disks in nearby star-forming regions with ages in the critical 1-30 Myr range over which gas clears out and planets form. 

In addition, spectral light was used to study gases and flames colored by the addition of various metal salts and transparent liquids, as well as to monitor the effects of photochemical changes. Based on his work on spectral analysis, Scheele established that there is a difference between actions of light and heat. This line of research was subsequently to lead to the discovery of the infrared region of the spectrum in 1800 by Friedrich Wilhelm Herschel (discussed above), and the ultraviolet region in 1801 by J.W. Ritter (discussed above). It also led William Hyde Wollaston to discover the ultraviolet region of the spectrum in 1802 he referred to this discovery as chemical rays. ... 

Fig. 1.3 (Left) Artist s impression of the disc and gas streams around HD 142527 [Credit ALMA (ESO/NAOJ/NRAO)/M. Kommesser (ESO)]. (Right) A Herschel PACS and SPIRE false colour map of Vela C (red = 250 tim, green = 160 p.m, blue = 70 p.m), highlighting regions of intense feedback (e.g. butterfly shaped RCW 36 in blue), the filamentary network, with the massive Vela ridge in the RCW 36 region, and cores forming stars [Credit ESA/PACS and SPIRE Consortia, T. HiU, F. Motte, Laboratoire AIM Paris-Saclay, CEA/IRFU CNRS/INSU Uni. Paris Diderot, HOBYS Key Programme Consortium]...

Although first reported by Herschel in 1800, the near-infrared (NIR) region was ignored until the late 1950s. Publications describing pharmaceutical applications appeared approximately 10 years later, with the majority appearing since 1986. Reviews of NIR spectroscopy were published in the early 1990s [1, 2] and contain references to earlier reviews. Ciurczak published a comprehensive review of pharmaceutical applications [3]. More recent reviews cover the various topics that are now studied by NIR [4-10]. Several texts on NIR are also available [11-16], several of which contain chapters on pharmaceutical applications. 

The famous astronomer WiUiam Herschel discovered infrared light, the invisible heat radiation, in 1800. His method was simple. A blackened thermometer bulb was heated in different regions of light that had been split into colors by a prism. When the bulb was placed in the dark region outside the red radiation it was heated up more than it had been in the red. 

The shortwave near-infrared spectral region was specifically discussed by Schrieve et al. They referred to synonyms such as the far-visible, the near, near-infrared, or the Herschel infrared to describe the range of approximately 700 to 1100 nm of the EMS (electromagnetic spectrum). The authors cite the increased interest of this spectral region to spectroscopists, particularly those involved with implementing process near-infrared measurements. More details regarding this spectral region are also described in a comprehensive handbook by Workman. ... 

---