infrared spectroscopy

infrared spectroscopy
NASA · Public domain · source
Name	Infrared spectroscopy
Field	Analytical chemistry
Invented	19th century
Inventors	William Herschel; Samuel Pierpont Langley

Contents

infrared spectroscopy

Infrared spectroscopy is an analytical technique that probes molecular vibrations by measuring absorption or emission of infrared radiation. It is widely used in laboratories and industry for qualitative identification and quantitative analysis, complementing techniques in Royal Institution, Imperial College London, Massachusetts Institute of Technology, California Institute of Technology. Pioneering work by figures associated with Royal Society and observatories such as Kew Observatory influenced development alongside instrumentation from firms like PerkinElmer and Bruker.

Overview

Infrared spectroscopy examines interactions between matter and electromagnetic radiation in the infrared region, linking instrumentation developed at institutions such as Harvard University, University of Cambridge, Max Planck Society to applications in settings including Siemens, General Electric, Shell plc. Historical milestones involved researchers connected to Royal Observatory, Greenwich, Smithsonian Institution, and patents filed through offices like the United States Patent and Trademark Office. The technique underpins applied work at Dow Chemical Company, DuPont, BASF, and in projects at NASA and European Space Agency.

Fundamental theory draws on quantum mechanics advanced at Princeton University, ETH Zurich, and Cavendish Laboratory. Vibrational transitions follow selection rules derived from models taught at University of Oxford, Columbia University, and developed by scientists affiliated with Institut Pasteur. Spectral positions reflect molecular force constants and reduced masses; theoretical interpretation has been refined using computational methods from groups at Sandia National Laboratories, Lawrence Berkeley National Laboratory, and software originating from collaborations with IBM and Microsoft Research.

Common instruments include dispersive spectrometers and Fourier-transform infrared spectrometers (FTIR) produced by companies such as Agilent Technologies, Thermo Fisher Scientific, and Shimadzu Corporation. Key components—sources, beamsplitters, detectors—were improved in labs like Bell Labs, Lawrence Livermore National Laboratory, and Rutherford Appleton Laboratory. Sampling accessories (attenuated total reflectance, diffuse reflectance) stem from innovations tested at National Institute of Standards and Technology, Brookhaven National Laboratory, and commercialized by firms including PerkinElmer. Techniques integrate with hyphenated systems developed in collaboration with researchers at Scripps Research, Johns Hopkins University, and University of California, Berkeley.

Measurement modes include transmission, reflection, attenuated total reflectance (ATR), and diffuse reflectance, with protocols established in standardization bodies like International Organization for Standardization, National Institute for Occupational Safety and Health, and American Society for Testing and Materials. Sample handling for solids, liquids, gases is practiced in laboratories at Yale University, University of Michigan, and University of Tokyo, and in industrial QA/QC at Procter & Gamble and Unilever. Cryogenic and high-temperature cells were developed with input from Argonne National Laboratory and Oak Ridge National Laboratory for specialized studies supported by grants from agencies such as National Institutes of Health and European Research Council.

Interpretation of spectra leverages reference libraries maintained by institutions like National Institute of Standards and Technology, American Chemical Society, and databases curated at Cambridge Crystallographic Data Centre. Applications span organic synthesis authentication in laboratories at Merck Group, Pfizer, and GlaxoSmithKline; environmental monitoring in programs by United Nations Environment Programme and Environmental Protection Agency; remote sensing missions by European Space Agency and NASA; forensic analyses at FBI laboratories and medical diagnostics in collaborations with Mayo Clinic and Cleveland Clinic. Multivariate analysis and chemometrics are applied using methods developed at Stanford University, Imperial College London, and University of Edinburgh.

Limitations include spectral congestion and overlapping bands, instrumental baseline drift, and sample matrix effects documented in standards from International Electrotechnical Commission and case studies from Food and Drug Administration. Common error sources—water vapor and CO2 interference, detector noise, and improper sampling—are mitigated following protocols from World Health Organization and training programs at American Chemical Society. Calibration and validation practices are informed by round-robin studies coordinated by National Physical Laboratory and proficiency testing in networks such as Society of Chemical Industry.