Editing Infrared spectroscopy (section)

==Uses and applications==
[[File:Mary Moffit using Infrared spectrophotometer 2012 017 b1f6 79407z11s.tiff|thumb|Infrared spectrophotometer used to analyze the [[DEET|diethyltoluamide]] insect repellent, 1960]]
[[File:Portable Screening Devices (1435) (8225044148).jpg|thumb|upright|US [[Food and Drug Administration]] scientist uses portable near infrared spectroscopy device to detect potentially illegal substances]]
Infrared spectroscopy is a simple and reliable technique widely used in both organic and inorganic chemistry, in research and industry. It is used in quality control, dynamic measurement, and monitoring applications such as the long-term unattended measurement of [[Carbon dioxide|CO<sub>2</sub>]] concentrations in greenhouses and growth chambers by infrared gas analyzers.{{citation needed|date=February 2024}}

It is also used in [[forensic analysis]] in both criminal and civil cases, for example in identifying [[polymer degradation]]. It can be used in determining the [[blood alcohol content]] of a suspected drunk driver.

IR spectroscopy has been used in identification of [[pigments]] in [[paintings]]<ref name="ColourLex">{{cite web | title=Infrared Spectroscopy | website=ColourLex | date=12 March 2021 | url=https://colourlex.com/project/infrared-spectroscopy/ | access-date=19 January 2022}}</ref> and other art objects<ref>{{cite book| vauthors = Derrick MR, Stulik D, Landry JM | url = http://www.getty.edu/conservation/publications_resources/pdf_publications/pdf/infrared_spectroscopy.pdf | title = Infrared Spectroscopy in Conservation Science|series= Scientific Tools for Conservation | publisher = Getty Publications | date = 1999| access-date = |isbn = 0-89236-469-6 }}</ref> such as [[illuminated manuscripts]].<ref>{{cite web | first = Paola | last = Ricciardi | name-list-style = vanc | url = http://www.labnews.co.uk/features/unlocking-the-secrets-of-illuminated-manuscripts-08-11-2012/ | title = Unlocking the secrets of illuminated manuscripts | access-date = 11 December 2015 }}</ref>

Infrared spectroscopy is also useful in measuring the degree of polymerization in [[polymer]] manufacture. Changes in the character or quantity of a particular bond are assessed by measuring at a specific frequency over time. Instruments can routinely record many spectra per second in situ, providing insights into reaction mechanism (e.g., detection of intermediates) and reaction progress.{{citation needed|date=February 2024}}

Infrared spectroscopy is utilized in the field of semiconductor microelectronics:<ref>{{cite book | vauthors = Lau WS |title= Infrared characterization for microelectronics|url=https://books.google.com/books?id=rotNlJDFJWsC |publisher= World Scientific |date= 1999 |isbn=978-981-02-2352-6}}</ref> for example, infrared spectroscopy can be applied to semiconductors like [[silicon]], [[gallium arsenide]], [[gallium nitride]], [[zinc selenide]], amorphous silicon, [[silicon nitride]], etc.

Another important application of infrared spectroscopy is in the [[food industry]] to measure the [[concentration]] of various compounds in different food products.<ref>{{cite encyclopedia | last1=Osborne|first1=Brian G. |title=Near-Infrared Spectroscopy in Food Analysis | name-list-style = vanc |encyclopedia= Encyclopedia of Analytical Chemistry |date=2006|publisher=John Wiley & Sons |doi=10.1002/9780470027318.a1018 |isbn=9780470027318}}</ref><ref>{{cite journal | vauthors = Villar A, Gorritxategi E, Aranzabe E, Fernández S, Otaduy D, Fernández LA | title = Low-cost visible-near infrared sensor for on-line monitoring of fat and fatty acids content during the manufacturing process of the milk | journal = Food Chemistry | volume = 135 | issue = 4 | pages = 2756–60 | date = December 2012 | pmid = 22980869 | doi = 10.1016/j.foodchem.2012.07.074 }}</ref>

Infrared spectroscopy is also used in gas leak detection devices such as the DP-IR and EyeCGAs.<ref>{{Cite web|url=http://heathus.com/product_category/gas/infrared-ir-optical-based/|title=Infrared (IR) / Optical Based Archives - Heath Consultants|last=www.TRMThemes.com|first=TRM Theme by|website=Heath Consultants|access-date=2016-04-12|archive-date=2022-01-20|archive-url=https://web.archive.org/web/20220120030138/https://heathus.com/product_category/gas/infrared-ir-optical-based/|url-status=dead}}</ref> These devices detect hydrocarbon gas leaks in the transportation of natural gas and crude oil.

Infrared spectroscopy is an important analysis method in the recycling process of household [[waste plastics]], and a convenient stand-off method to sort plastic of different polymers ([[Polyethylene terephthalate|PET]], [[HDPE]], ...).<ref>{{cite journal |title=Detection of Black Plastics in the Middle Infrared Spectrum (MIR) Using Photon Up-Conversion Technique for Polymer Recycling Process |last1=Becker |first1=Wolfgang |last2=Sachsenheimer |first2=Kerstin |last3=Klemenz |first3=Melanie |journal=Polymers |volume=9 |number=9 |doi=10.3390/polym9090435 |doi-access=free |year=2017 |publisher=MDPI |pmid=30965736 |pmc=6418689 |url=https://www.mdpi.com/2073-4360/9/9/435/pdf}}</ref>

Other developments include a miniature IR-spectrometer that's linked to a cloud based database and suitable for personal everyday use,<ref>{{Cite web|url=https://spectrum.ieee.org/israeli-startup-consumer-physics-says-its-scio-food-analyzer-is-finally-ready-for-prime-timeso-we-took-it-grocery-shopping|title=What Happened When We Took the SCiO Food Analyzer Grocery Shopping|website=IEEE Spectrum: Technology, Engineering, and Science News|access-date=2017-03-23|date=2017-03-14 |last=Perry |first=Tekla S.}}</ref> and NIR-spectroscopic chips<ref>{{Cite web|url=http://www.americanpharmaceuticalreview.com/Featured-Articles/163573-A-Review-of-New-Small-Scale-Technologies-for-Near-Infrared-Measurements/|title=A Review of New Small-Scale Technologies for Near Infrared Measurements|website=American Pharmaceutical Review|access-date=2017-03-23|date=18 June 2014|last=Coates |first=John |publisher=Coates Consulting LLC}}</ref> that can be embedded in smartphones and various gadgets.

In catalysis research it is a very useful tool to characterize the catalyst,<ref>{{Cite journal|last1=Boosa|first1=Venu|last2=Varimalla|first2=Shirisha|last3=Dumpalapally|first3=Mahesh|last4=Gutta|first4=Naresh|last5=Velisoju|first5=Vijay Kumar|last6=Nama|first6=Narender|last7=Akula|first7=Venugopal|date=2021-09-05|title=Influence of Brønsted acid sites on chemoselective synthesis of pyrrolidones over H-ZSM-5 supported copper catalyst|url=https://www.sciencedirect.com/science/article/pii/S0926337321003039|journal=Applied Catalysis B: Environmental|language=en|volume=292|pages=120177|doi=10.1016/j.apcatb.2021.120177|bibcode=2021AppCB.29220177B |issn=0926-3373}}</ref><ref>{{Cite journal|last1=Fajdek-Bieda|first1=Anna|last2=Wróblewska|first2=Agnieszka|last3=Miądlicki|first3=Piotr|last4=Tołpa|first4=Jadwiga|last5=Michalkiewicz|first5=Beata|date=2021-08-01|title=Clinoptilolite as a natural, active zeolite catalyst for the chemical transformations of geraniol|journal=Reaction Kinetics, Mechanisms and Catalysis|language=en|volume=133|issue=2|pages=997–1011|doi=10.1007/s11144-021-02027-3|s2cid=236149569|issn=1878-5204|doi-access=free}}</ref><ref>{{Cite journal|last1=Azancot|first1=Lola|last2=Bobadilla|first2=Luis F.|last3=Centeno|first3=Miguel A.|last4=Odriozola|first4=José A.|date=2021-05-15|title=IR spectroscopic insights into the coking-resistance effect of potassium on nickel-based catalyst during dry reforming of methane|url=https://www.sciencedirect.com/science/article/pii/S092633732031239X|journal=Applied Catalysis B: Environmental|language=en|volume=285|pages=119822|doi=10.1016/j.apcatb.2020.119822|bibcode=2021AppCB.28519822A |hdl=10261/251396 |s2cid=232627637|issn=0926-3373|hdl-access=free}}</ref> as well as to detect intermediates<ref>{{Cite journal|last1=Nuguid|first1=Rob Jeremiah G.|last2=Elsener|first2=Martin|last3=Ferri|first3=Davide|last4=Kröcher|first4=Oliver|date=2021-12-05|title=Operando diffuse reflectance infrared detection of cyanide intermediate species during the reaction of formaldehyde with ammonia over V2O5/WO3-TiO2|journal=Applied Catalysis B: Environmental|language=en|volume=298|pages=120629|doi=10.1016/j.apcatb.2021.120629|issn=0926-3373|doi-access=free}}</ref>

Infrared spectroscopy coupled with machine learning and artificial intelligence also has potential for rapid, accurate and non-invasive sensing of bacteria.<ref>{{Cite journal |last1=Sockalingum |first1=G. D. |last2=Bouhedja |first2=W. |last3=Pina |first3=P. |last4=Allouch |first4=P. |last5=Bloy |first5=C. |last6=Manfait |first6=M. |date=February 1998 |title=FT-IR spectroscopy as an emerging method for rapid characterization of microorganisms |url=https://pubmed.ncbi.nlm.nih.gov/9551657 |journal=Cellular and Molecular Biology (Noisy-Le-Grand, France) |volume=44 |issue=1 |pages=261–269 |issn=0145-5680 |pmid=9551657}}</ref> The complex chemical composition of bacteria, including nucleic acids, proteins, carbohydrates and fatty acids, results in high-dimensional datasets where the essential features are effectively hidden under the total spectrum. Extraction of the essential features therefore requires advanced statistical methods such as machine learning and deep-neural networks. The potential of this technique for bacteria classification have been demonstrated for differentiation at the genus,<ref>{{Cite journal |last1=Helm |first1=D. |last2=Labischinski |first2=H. |last3=Schallehn |first3=Gisela |last4=Naumann |first4=D. |date=1991-01-01 |title=Classification and identification of bacteria by Fourier-transform infrared spectroscopy |journal=Microbiology |language=en |volume=137 |issue=1 |pages=69–79 |doi=10.1099/00221287-137-1-69 |doi-access=free |pmid=1710644 |issn=1350-0872}}</ref> species<ref>{{Cite journal |last1=Holt |first1=C |last2=Hirst |first2=D |last3=Sutherland |first3=A |last4=MacDonald |first4=F |date=January 1995 |title=Discrimination of species in the genus Listeria by Fourier transform infrared spectroscopy and canonical variate analysis |journal=Applied and Environmental Microbiology |language=en |volume=61 |issue=1 |pages=377–378 |doi=10.1128/aem.61.1.377-378.1995 |issn=0099-2240 |pmc=167294 |pmid=7887620|bibcode=1995ApEnM..61..377H }}</ref> and serotype<ref>{{Cite journal |last1=Campos |first1=Joana |last2=Sousa |first2=Clara |last3=Mourão |first3=Joana |last4=Lopes |first4=João |last5=Antunes |first5=Patrícia |last6=Peixe |first6=Luísa |date=November 2018 |title=Discrimination of non-typhoid Salmonella serogroups and serotypes by Fourier Transform Infrared Spectroscopy: A comprehensive analysis |url=https://linkinghub.elsevier.com/retrieve/pii/S0168160518303465 |journal=International Journal of Food Microbiology |language=en |volume=285 |pages=34–41 |doi=10.1016/j.ijfoodmicro.2018.07.005|pmid=30015261 }}</ref> taxonomic levels, and it has also been shown promising for antimicrobial susceptibility testing,<ref>{{Cite journal |last1=Sharaha |first1=Uraib |last2=Rodriguez-Diaz |first2=Eladio |last3=Sagi |first3=Orli |last4=Riesenberg |first4=Klaris |last5=Salman |first5=Ahmad |last6=Bigio |first6=Irving J. |last7=Huleihel |first7=Mahmoud |date=July 2019 |title=Fast and reliable determination of Escherichia coli susceptibility to antibiotics: Infrared microscopy in tandem with machine learning algorithms |url=https://onlinelibrary.wiley.com/doi/10.1002/jbio.201800478 |journal=Journal of Biophotonics |language=en |volume=12 |issue=7 |pages=e201800478 |doi=10.1002/jbio.201800478 |pmid=30916881 |issn=1864-063X}}</ref><ref>{{Cite journal |last1=Wijesinghe |first1=Hewa G. S. |last2=Hare |first2=Dominic J. |last3=Mohamed |first3=Ahmed |last4=Shah |first4=Alok K. |last5=Harris |first5=Patrick N. A. |last6=Hill |first6=Michelle M. |date=2021 |title=Detecting antimicrobial resistance in Escherichia coli using benchtop attenuated total reflectance-Fourier transform infrared spectroscopy and machine learning |url=http://xlink.rsc.org/?DOI=D1AN00546D |journal=The Analyst |language=en |volume=146 |issue=20 |pages=6211–6219 |doi=10.1039/D1AN00546D |pmid=34522918 |bibcode=2021Ana...146.6211W |issn=0003-2654}}</ref><ref>{{Cite journal |last1=Suleiman |first1=Manal |last2=Abu-Aqil |first2=George |last3=Sharaha |first3=Uraib |last4=Riesenberg |first4=Klaris |last5=Lapidot |first5=Itshak |last6=Salman |first6=Ahmad |last7=Huleihel |first7=Mahmoud |date=June 2022 |title=Infra-red spectroscopy combined with machine learning algorithms enables early determination of Pseudomonas aeruginosa's susceptibility to antibiotics |url=https://linkinghub.elsevier.com/retrieve/pii/S1386142522002281 |journal=Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy |language=en |volume=274 |pages=121080 |doi=10.1016/j.saa.2022.121080|pmid=35248858 |bibcode=2022AcSpA.27421080S }}</ref> which is important for many clinical settings where faster susceptibility testing would decrease unnecessary blind-treatment with broad-spectrum antibiotics. The main limitation of this technique for clinical applications is the high sensitivity to technical equipment and sample preparation techniques, which makes it difficult to construct large-scale databases. Attempts in this direction have however been made by Bruker with the IR Biotyper for food microbiology.<ref>{{Cite web |title=IR Biotyper® for Food Microbiology |url=https://www.bruker.com/en/applications/microbiology-and-diagnostics/food-beverage-microbiology/ir-biotyper-for-food-microbiology.html |access-date=2024-03-20 |website=www.bruker.com |language=en}}</ref>