FT-IR microscopy

Other recent applications of FT-IR in pharmaceutical analysis include reaction monitoring by fiberoptic FT-IR/ATR spectroscopy140 and stability studies of pharmaceutical emulsions using FT-IR microscopy.141 A novel equipment cleaning verification procedure using grazing angle fiberoptic FT-IR reflection-absorption spectroscopy was described by Perston et al.142... 

IR spectroscopy is a fast, simple, and cheap method for the qualitative detection of certain functional groups on insoluble supports [77-79]. Dried supports can be used directly to prepare KBr pellets for standard recording of IR spectra [54,80-82], Newer IR-based techniques, which require much less support material than required for a KBr pellet, include single-bead FT-IR spectroscopy [16,77,83-86], single-bead Raman spectroscopy [87], near-IR multispectral imaging [88], and the simultaneous analysis of several different beads by FT-IR microscopy for analysis of combinatorial libraries [89,90],... 

Chiriboga, L., Yee, H. and Diem, M. (2000) Infrared spectroscopy of human cells and tissue. Part VII FT-IR microscopy of DNAase- and RNAase-treated normal, cirrhotic, and neoplastic liver tissue. Appl. Spectrosc. 54, 480-5. 

Bruker has introduced an FT-Raman microscope which is an accessory to an FT-IR spectrometer (42). The coupling between the microscope and the Raman module is made by NIR-fiber optics. In the wavelength range of the Raman experiment excited by a Nd YAG laser, the fiber optics transmission is at a maximum, thus allowing the experiment to be successful (43). Spatial resolution down to 5//m can be achieved. The technique appears to be a capable adjunct to FT-IR microscopy. 

Because of the simple sample preparation, FT-IR spectroscopy [12,13] has become an increasingly popular method in SPOS for reaction monitoring. For IR spectra in the transmission mode [14,15] or with ATR-[16],FT-Raman-[17,18] and DRIFTS-[19] methods, only 1-2 mg of resin beads are required for routine measurements. With FT-IR microscopy [20-24], it is even possible to obtain spectra from single resin beads or spatially resolved spectra [25]. 

Figure 16.7. Monitoring of the formation of N,N-dipropargyle amide via FT-IR-microscopy. (A) Polystyrene hydroxy methyl resin (v(0—H) = 3450 cm 1) (B) resin-bound moiety 2 (v(C(0)—Cl = 1800, v(COOR) = 1740 cm 1) (C) resin-bound moiety 3 (v(alkine C-H) = 3288,v(C=C) = 2120, v(COOR) = 1740 and v(CONR2) = 1670 cm-1. (Reproduced from (20].)...

Figure 16.8. Time-resolved FT-IR-microscopy. The relative intensities of the carbonyl vibration (1722/1943 cm1) and the N—O vibration (1540/1943 cm - ) of compound 5 arc applied versus time. (Reproduced from [20].)...

Ghetti, P., A. Ghedini, and R. Stradi. 1994. Analytical potential of FT-IR microscopy. I. Applications to the drug polymorphism study. Boll. Chim. Farm. 133 689-697. 

Figure 7 Extreme examples of presses for preparing from solids films suifable for mid-infrared examinafion (A) hand-operafed, hydraulic, heafed, molding press for preparing fhin films from polymer samples for macro mid-infrared examinafions (B) diamond anvil minicell for solid sample compression and confainmenf, particularly for FT-IR microscopy sfudies and (C) schemafic of diamond anvil minicell. (A) Reproduced by kind permission of George E. Moore Son Lfd., Birmingham, Wesf Midlands, UK. (B and C) Reproduced by kind permission of High Pressure Diamond Optics, Inc., Tucson, AZ, USA.)...

Microtomed sections Sections of appropriate thickness for transmission infrared measurements may be microtomed from continuous solid samples. This presentation method is particularly useful for FT-IR microscopy. 

FT-IR spectroscopy is becoming a techniqne of choice for the analysis and characterisation of materials. It provides a unique fingerprint of the sample, which can lead to a positive identification within minutes. In the past, the problem was how to handle the sample and whether there was sufficient sample to obtain an adequate spectrum. As early as 1949 it was appreciated that one solntion was to ntilise the handling and viewing capabilities of a microscope, i.e., FT-IR microscopy. 

When studying samples by FT-IR microscopy, there are two major optical factors to be considered if the best results are to be obtained. The two primary sources of error are ... 

FT-IR microscopy has been applied to the examination of polymer films, polymer laminates, and polymeric printing inks or coatings on metal cans. It has been used to identify defects, imperfections, and inclusions in films and laminates. Inclusions not on the surface can be revealed for analysis by cutting across sections with a microtome. Polarised FT-IR microscopy studies have been performed, using a grid wire polariser, on... 

FT-IR microscopy has been applied to a study of the effect of weathering on the degradation of PP sheet after two years of outdoor exposure. Plots of 1712 cm Vll63 cm" absorption ratio (1712 cm" carbonyl absorption) versus depth from the exposed polymer surfaces showed that degradation extended deep within the polymer sheet showing an exponential decrease from the outer surface typical of a diffusion-controlled process. 

Applications of FT-IR Microscopy to Polymer Analysis, Spectratech Application Note Volume No.lO, Spectratech Lord, 1988. 

By combining Raman imaging with photoacoustic FT-IR and FT-IR microscopy three-dimensional maps of the heterogeneous degradation of epoxy and polyurethane films exposed to UV and water vapor were obtained [241]. Similarly, the phase separation in styrene/butylacrylate copolymers and latex films were analyzed [242]. Blakey and George used point illumination Raman mapping to investigate the surface of photooxidized PP with a lateral resolution of 1 im and successfully mapped the distribution of both oxidation products (Q ,/3-unsaturated ketones) and catalyst residues [239]. The distri-... 

Cellulose Poly(carboxybetaine acrylamide) Streptavidin Xmax = 320 nm 2 h, RT, DCM yes (PCBAAm) no (Streptavidin) For PCBAAm XPS, ToF-SIMS, FT-IR microscopy imaging For Streptavidin XPS, UV/VIS, fouling studies [TIS 14b]... 

HAN 12a] Hansson S., Tischer T., Goldmann A.S. et al, Visualization of poly(methyl methacrylate) (PMMA) grafts on cellulose via high-resolution FT-IR microscopy imaging , Polymer Chemistry, vol. 3, pp. 307-309, 2012. 

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