Raman on-line

J. J. Freeman, D.O. Fisher and G.J. Gervasio, FT-Raman on-line analysis of PCI3 reactor material, Appl. Spectrosc., 47, 1115-1122 (1993). 

Freeman, J.J. Fisher, D.O. Gervasio, G.J. FT-Raman On-Line Analysis of PC13 Reactor Material Appl. Spectrosc. 1993, 47, 1115-1122. 

Nijhuis TA, Tinnemans SJ, Visser T, Weckhuysen BM. Operando spectroscopic investigation of supported metal oxide catalysts by combined time-resolved UV-VIS/ Raman/on-line mass spectrometry. Physical Chemistry Chemical Physics 2003, 5, 4361 1365. 

Shen X M, FT-IR andNIR FT-Raman On-line Measurement of the Synthesis of Reactive Dyes, PhD Thesis, University of Leeds, 1998. 

In addition, new technology developments, such as on-line Raman spectroscopy, x-ray diffraction and gc/lc are under commercialization for the 1990s. 

The on-line principle has also been extended into the field of detection (Fig. 8). Thus, it is now possible to record FTIR [27-31] and Raman spectra in situ [32, 33], and there have been considerable advances in the on-line coupling of thin-layer chromatography with mass spectrometry. Here it has been, above all, the research groups of Wilson [34-36] and Busch [37-40] that have made the necessary instrumental and methodological advances, so that TLC must no longer be viewed as merely a clean-up method. Rather it forms the essential central point for all these on-line coupling techniques. 

Various techniques have been introduced which still lack specific applications in polymer/additive analysis, but which may reasonably be expected to lead to significant contributions in the future. Examples are LC-QToFMS, LC-multi-API-MS, GC-ToFMS, Raman spectroscopy (to a minor extent), etc. Expectations for DIP-ToFMS [132], PTV-GC-ToFMS [133] and ASE are high. The advantages of SFC [134,135], on-line multidimensional chromatographic techniques [136,137] and laser-based methods for polymer/additive analysis appear to be more distant. Table 10.33 lists some innovative polymer/additive analysis protocols. As in all endeavours, the introduction of new technology needs a champion. 

Raman spectral database available on-line at address http //www.chem.ucl.ac.uk/ resources/raman/speclib.html. 

Clearly, the potential applications for vibrational spectroscopy techniques in the pharmaceutical sciences are broad, particularly with the advent of Fourier transform instrumentation at competitive prices. Numerous sampling accessories are currently available for IR and Raman analysis of virtually any type of sample. In addition, new sampling devices are rapidly being developed for at-line and on-line applications. In conjunction with the numerous other physical analytical techniques presented within this volume, the physical characterization of a pharmaceutical solid is not complete without vibrational analysis. 

Lipp, E. D. Grosse, R. L., On line monitoring of chlorosilane streams by Raman spectroscopy, Appl. Spectrosc. 1998, 52, 42 46... 

Sivakesava et al. also used Raman (as well as FT-IR and NIR) to perform a simultaneous on-line determination of biomass, glucose, and lactic acid in lactic acid fermentation by Lactobacillus casei.2 Partial least squares (PLS) and principal components regression (PCR) equations were generated after suitable wavelength regions were determined. The best standard errors were found to be glucose, 2.5 g/1 lactic acid, 0.7 g/1 and optical cell density, 0.23. Best numbers were found for FT-IR with NIR and Raman being somewhat less accurate (in this experiment). 

Similar work was performed by Shaw et al.3 in 1999 when they used FT-Raman, equipped with a charge coupled device (CCD) detector (for rapid measurements) as an on-line monitor for the yeast biotransformation of glucose to ethanol. An ATR (attenuated total reflectance) cell was used to interface the instrument to the fermentation tank. An Nd YAG laser (1064 nm) was used to lower fluorescence interference and a holographic notch filter was employed to reduce Rayleigh scatter interference. Various chemometric approaches were explored and are explained in detail in their paper. The solution was pumped continuously through a bypass, used as a window in which measurements were taken. 

P. Niemela, J. Sumen and J. Suhonen, Dual-laser CCD-Raman spechometer applied to on-line measurement of... 

C. Cannizzaro, M. Rhiel, 1. Marison and U. von Stockar, On-line monitoring of Phaffia rhodozyma fed-batch process with in situ dispersive Raman spectroscopy, Biotechnol. Bioeng., 83, 668-680 (2003). 

D.S. Hausman, R.T. Cambron and A. Sakr, Application of Raman spectroscopy for on-line monitoring of low dose blend nniformity, Int. J. Pharm., 298, 80-90 (2005). 

G.J. Gervasio and M.J. Pelletier, On-line Raman analysis of PCI3 reactor material. Journal of Process Analytical Chemistry, III, 7-11 (1997). 

ExxonMobil Chemical Company, On-line properties analysis of a molten polymer by Raman spectroscopy for control of a mixing device. Inventors D.G. Marrow, D.A. Yahn, and T.R. Veariel. 20 pp. (inch 10 fig.). Appl. 22 Jul 2005. Int. Cl. GOIJ 3/44 GOIN 21/65. US Patent Application Publication 2007/0019190 Al 105. V.S. Tumuluri, M.S. Kemper, I.R. Lewis, S. Prodduturi, S. Majumdar, B.A. Avery and M.A. Repka, Off-line and on-line measurements of drug-loaded hot-melt extruded films using Raman spectroscopy, Int. J. Pharm., 357, 77-84 (2008). 

G.M. Hamminga, G. Mul and J.A. Moulijn, Applicability of fiber-optic-based Raman probes for on-line reaction monitoring of high-pressure catalytic hydrogenation reactions, Appl. Spectrosc., 61, 470 78 (2007). 

E. Venardou, E. Garcia-Verdugo, S.J. Barlow, Y.E. Gorbaty and M. Poliakoff, On-line monitoring of the hydrolysis of acetonitrile in near-critical water using Raman spectroscopy, Vib. Spectrosc., 35, 103-109 (2004). 

E. Widjaja, Y.Y. Tan and M. Garland, Application of band-target entropy minimization to on-line Raman monitoring of an organic synthesis. An example of new technology for process analytical technology, Org. Process Res. Dev., 11, 98-103 (2007). 

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