Cellulose, near infrared

The acetyl content of cellulose acetate may be calculated by difference from the hydroxyl content, which is usually determined by carbanilation of the ester hydroxy groups in pyridine solvent with phenyl isocyanate [103-71-9J, followed by measurement of uv absorption of the combined carbanilate. Methods for determining cellulose ester hydroxyl content by near-infrared spectroscopy (111) and acid content by nmr spectroscopy (112) and pyrolysis gas chromatography (113) have been reported. 

The phase composition of glycine crystal forms during the drying step of a wet granulation process has been studied, and a model developed for the phase conversion reactions [88], X-ray powder diffraction was used for qualitative analysis, and near-infrared spectroscopy for quantitative analysis. It was shown that when glycine was wet granulated with microcrystalline cellulose, the more rapidly the granulation... 

A. Gupta, G.E. Peck, R.W. Miller and K.R. Morris, Influence of ambient moisture on the compaction behavior of microcrystalline cellulose powder undergoing uni-axial compression and roller compaction a comparative study using near-infrared spectroscopy, J. Pharm. Sci., 94(10), 2301-2313 (2005). 

S.R. Delwiche, K.H. Norris and R.E. Pitt, Temperature sensitivity of near-infrared scattering transmittance spectra of water-adsorbed starch and cellulose, App/. Spectrosc., 46, 782-789 (1992). 

A.J. O Neil, R.D. Jee and A.C. Moffat, Measurement of the cumulative particle size distribution of microcrystalline cellulose using near infrared reflectance spectroscopy. Analyst, 124, 33-36 (1999). 

Figure 6 Near-infrared spectra of wheat fractions (Wetzel, D. L. Mark, H. "Spectroscopic Determination of Cellulose as Criterion of Flour Purity with Respect to Bran", American Association of Cereal Chemists 62nd Annual Meeting, San Francisco, CA 1977).

A fiber optic probe was used by Blanco et al. for analysis of spasmoctyl samples with the active compound otilonium bromide and cellulose, maize starch, sodium starch glycolate, and glyceryl palmitostearate as excipients. Another study from this group covered the identification, qualification of the substance, and the quantification of the active component. A library search with a comparison to the near-infrared spectra of 163 pharmaceuticals was involved. An on-line monitoring for the determination of the endpoint of polymorph conversions in pharmaceutical processes was recently described further investigations into this field were published and are noted previously. ... 

UP Agarwal and N Kawai. Self-Absorption Phenomenon in Near-Infrared Fourier Transform Raman Spectroscopy of Cellulosic and LignoceUnlosic Materials. Appl. 

JA Wright, MD Birkett, and MIT Gambino. Prediction of Pulp Yield and Cellulose Content from Wood Samples Using Near-Infrared Reflectance Spectroscopy. Tappi J. 73 164-166, 1990. 

ME Martin and ID Aber. Analyses of Forest Foliage III Determining Nitrogen, Lignin and Cellulose in Fresh Leaves Using Near Infrared Reflectance Data. Near Infrared Spectrosc. 2 25-32, 1994. 

McLellan, T. M., J. D. Aber, M. E. Martin, J. M. Melillo K. J. Nadelhoffer, 1991a Determination of nitrogen, lignin and cellulose content of decomposing leaf material by near infrared reflectance... 

Ground-state absorption spectrum for powdered microcrystalline cellulose is also shown in Figure 1. It exhibits R values quite close to unity for visible (Vis) and near infrared (NIR) spectral regions and shows a significative absorption in the ultraviolet (UV). Silica and silicalite also have a reflectance close to unity in the Vis and NIR regions and differ from cellulose by the fact that UV absorption is smaller. In the case of silicas with different porosity, but with the same particle size, significant variations of the reflectance were detected [7]. 

Another important characteristic of bacterial cellulose is its capacity to block most of the ultraviolet radiation from sunlight. The UV spectral region is subdivided into UV-A (320-400 nm), UV-B (280-320 nm) and UV-C (below 280nm). UV-C is not considered here, since it is absorbed by the atmosphere. Figure 17.10 shows the transmittance spectrum of a bacterial cellulose membrane from the UV (250-400 nm) to the near-infrared... 

Figure 17.10 UV-Visible and near-infrared transmittance spectmm of a 200-fji,m thick bacterial cellulose membrane. The insert shows the magnification of the 250 00 nm range.

Baley C, Busnel F, Grohens Y, Sire O (2006) Influence of chemical treatments rai surface properties and adhesion of flax fiber-polyester resin. Compos A 37(10) 1626-1637 Barton F, Akin D, Morrison W, Ulrich A, Archibald D (2002) Analysis of fiber content in flax stems by near-infrared spectroscopy. J Agric Food Chem 50(26) 7576-7580 Basu S, Bhattacharyya J (1951) Mildew of complex vegetable fibers. J Sci Ind Res 10B(4) 91-93 Berkley E (1949) Certain variations in the structure and properties of natural cellulose fibers. Text Res J 19(60) 91-93... 

Delwiche, S.R., Pitt, R.E., and Norris, K.H., Sensitivity of near-infrared absorption to moisture content versus water activity in starch and cellulose. Cereal Chem., 69(1), 107-109, 1992. 

Carbohydrates include saccharides and polysaccharides, or sugars and starches, and cellulosic or lignin type biotnolecules. They consist mostly of aliphatic cyclic groups with attached OH groups and ether linkages. Lignin is representative of aromatic natural product compounds. Thus, the bands normally associated with these functional groups may be observed in the near-infrared (NIR) spectra of carbohydrate molecules. 

Mitchell, J.A., C.D. Bockman, and A.V. Lee, Determination of Acetyl Content of Cellulose Acetate by Near-Infrared Spectroscopy. Anal. Chem., 1957. 29 499-502. 

De Wit, J.S. and D. Dugger, Routine Testing of Cellulose Esters by Near Infrared Spectroscopy, in Pmcess Contml and Quality, 1992. 2 123. 

Useful reviews of the application of near infrared -to the study of various classes of compound are as follows organic compounds, polymers, silicon compounds, pharmaceuticals," food, - petrochemicals, - agricultural products, -" surface hydrolysis of cellulose, biological and medical. ... 

Langkilde, F. W. Svantesson, A. J. (1995). Indentification of celluloses with Fourier-Transform (FT) mid-infrared, FT-Raman and near-infrared spectrometry. Journal of Pharmaceutical Biomedical Analysis, 13, 409-414. 

Seip 36 is a charred material with a red cast (9) it also has a high iron content. The infrared spectrum of the particulate recovered from Seip 36 (Figure 12) looks like charred cellulose and shows no charred protein. The spectrum is not the same as charred milkweed but it appears more similar to charred Indian hemp (Figure 13), with bands near 1582 cm-1 and 1400 cm 1. 

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