scholarly journals Subcellular Biochemical Investigation of Purkinje Neurons Using Synchrotron Radiation Fourier Transform Infrared Spectroscopic Imaging with a Focal Plane Array Detector

2013 ◽  
Vol 4 (7) ◽  
pp. 1071-1080 ◽  
Author(s):  
Mark J. Hackett ◽  
Ferenc Borondics ◽  
Devin Brown ◽  
Carol Hirschmugl ◽  
Shari E. Smith ◽  
...  
1997 ◽  
Vol 51 (4) ◽  
pp. 563-567 ◽  
Author(s):  
E. Neil Lewis ◽  
Linda H. Kidder ◽  
John F. Arens ◽  
Michael C. Peck ◽  
Ira W. Levin

An instrument is described that simultaneously records images and spectra of materials in the infrared fingerprint region using a long-wavelength infrared focal-plane array detector, a step-scan Michelson interferometer, and an infrared microscope. With the combination of step-scan Fourier transform (FT) Michelson interferometry and arsenic-doped silicon (Si: As) focal-plane array image detection, an infrared spectroscopic imaging system has been constructed that maintains both an instrumental multiplex and multichannel advantage and operates from approximately 4000 to 400 cm−1. With this method of mid-infrared spectroscopic imaging, the fidelity of the generated spectral images recorded through the microscope is solely determined by the number of pixels on the focal-plane array detector, and only a few seconds of data acquisition time are required for spectral image acquisition. This seamless combination of spectroscopy for molecular analysis and the power of visualization represents the future of infrared microscopy. Step-scan imaging principles, the operation and characteristics of long-wavelength array detectors, and instrument design details are outlined, and infrared chemical imaging results are presented. The results are discussed with respect to their implications for the chemical analysis of a variety of solid-state materials.


2015 ◽  
Vol 12 (5) ◽  
pp. 563 ◽  
Author(s):  
Martin Günter Joachim Löder ◽  
Mirco Kuczera ◽  
Svenja Mintenig ◽  
Claudia Lorenz ◽  
Gunnar Gerdts

Environmental context Microplastics are of increasing environmental concern following reports that they occur worldwide from the arctic to the deep sea. However, a reliable methodology that facilitates an automated measurement of abundance and identity of microplastics is still lacking. We present an analytical protocol that applies focal plane array detector-based infrared imaging of microplastics enriched on membrane filters applicable to investigations of microplastic pollution of the environment. Abstract The pollution of the environment with microplastics (plastic pieces <5 mm) is a problem of increasing concern. However, although this has been generally recognised by scientists and authorities, the analysis of microplastics is often done by visual inspection alone with potentially high error rates, especially for smaller particles. Methods that allow for a fast and reliable analysis of microplastics enriched on filters are lacking. Our study is the first to fill this gap by using focal plane array detector-based micro-Fourier-transform infrared imaging for analysis of microplastics from environmental samples. As a result of our iteratively optimised analytical approach (concerning filter material, measuring mode, measurement parameters and identification protocol), we were able to successfully measure the whole surface (>10-mm diameter) of filters with microplastics from marine plankton and sediment samples. The measurement with a high lateral resolution allowed for the detection of particles down to a size of 20 μm in only a fractional part of time needed for chemical mapping. The integration of three band regions facilitated the pre-selection of potential microplastics of the ten most important polymers. Subsequent to the imaging the review of the infrared spectra of the pre-selected potential microplastics was necessary for a verification of plastic polymer origin. The approach we present here is highly suitable to be implemented as a standard procedure for the analysis of small microplastics from environmental samples. However, a further automatisation with respect to measurement and subsequent particle identification would facilitate the even faster and fully automated analysis of microplastic samples.


2004 ◽  
Vol 58 (11) ◽  
pp. 1364-1368 ◽  
Author(s):  
Jonah Kirkwood ◽  
Sufian F. Al-Khaldi ◽  
Magdi M. Mossoba ◽  
Jacqueline Sedman ◽  
Ashraf A. Ismail

1995 ◽  
Vol 49 (5) ◽  
pp. 672-678 ◽  
Author(s):  
E. Neil Lewis ◽  
Ira W. Levin

A different approach toward mid-infrared spectroscopic imaging microscopy is introduced in which instrumentation is designed about an InSb multichannel, focal-plane array detector and a variable-bandpass dielectric filter. The system may be configured for either macroscopic or microscopic applications, and high-fidelity, chemically specific images may be acquired in real time. With the dielectric filter used in this assembly, continuous tuning is provided for the infrared 4000–2320 cm−1 spectral region with spectral resolutions of approximately 35–18 cm−1 at the extremes of this wavelength interval. The functioning of the imaging microscope is demonstrated with samples including polystyrene microspheres, preparations of lipids and an amino acid embedded in KBr disks, and a tissue sample derived from a coronal slice of a monkey cerebellum.


1995 ◽  
Vol 67 (19) ◽  
pp. 3377-3381 ◽  
Author(s):  
E. Neil. Lewis ◽  
Patrick J. Treado ◽  
Robert C. Reeder ◽  
Gloria M. Story ◽  
Anthony E. Dowrey ◽  
...  

2003 ◽  
Vol 57 (4) ◽  
pp. 357-366 ◽  
Author(s):  
Rohit Bhargava ◽  
Ira W. Levin

Fourier transform infrared (FT-IR) imaging allows simultaneous spectral characterization of large spatial areas due to its multichannel detection advantage. The acquisition of large amounts of data in the multichannel configuration results, however, in a poor temporal resolution of sequentially acquired data sets, which limits the examination of dynamic processes to processes that have characteristic time scales of the order of minutes. Here, we introduce the concept and instrumental details of a time-resolved infrared spectroscopic imaging modality that permits the examination of repetitive dynamic processes whose half-lives are of the order of milliseconds. As an illustration of this implementation of step-scan FT-IR imaging, we examine the molecular responses to external electric-field perturbations of a microscopically heterogeneous polymer–liquid crystal composite. Analysis of the spectroscopic data using conventional univariate and generalized two-dimensional (2D) correlation methods emphasizes an additional capability for accessing of simultaneous spatial and temporal chemical measurements of molecular dynamic processes.


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