Editing Ultraviolet–visible spectroscopy (section)

{{Short description|Range of spectroscopic analysis}}{{More citations needed|date=April 2018}}[[Image:DU640 spectrophotometer.jpg|thumb|right|270px|Beckman DU640 UV-Vis spectrophotometer]]

'''Ultraviolet–visible spectrophotometry''' ('''UV–Vis''' or '''UV-VIS''')<ref>{{Citation |last1=Cole |first1=Kenneth |title=Ultraviolet-Visible Spectrophotometry |date=2020 |url=https://doi.org/10.1007/978-3-030-42917-1_10 |work=Principles of Forensic Toxicology |pages=127–134 |editor-last=Levine |editor-first=Barry S. |access-date=2023-10-19 |place=Cham |publisher=Springer International Publishing |language=en |doi=10.1007/978-3-030-42917-1_10 |isbn=978-3-030-42917-1 |last2=Levine |first2=Barry S. |editor2-last=Kerrigan |editor2-first=Sarah|url-access=subscription }}</ref><ref name=":1">{{Cite book |last=Vitha |first=Mark F. |title=Spectroscopy: principles and instrumentation |publisher=John Wiley & Sons |year=2018 |isbn=978-1-119-43664-5 |location=Hoboken, NJ |chapter=Chapter 2}}</ref><ref>{{Citation |last1=Edwards |first1=Alison A. |title=UV-Visible Absorption Spectroscopy, Organic Applications |date=2017-01-01 |url=https://www.sciencedirect.com/science/article/pii/B9780128032244000133 |encyclopedia=Encyclopedia of Spectroscopy and Spectrometry (Third Edition) |pages=511–519 |editor-last=Lindon |editor-first=John C. |access-date=2023-10-19 |place=Oxford |publisher=Academic Press |doi=10.1016/b978-0-12-803224-4.00013-3 |isbn=978-0-12-803224-4 |last2=Alexander |first2=Bruce D. |editor2-last=Tranter |editor2-first=George E. |editor3-last=Koppenaal |editor3-first=David W.|url-access=subscription }}</ref> refers to [[absorption spectroscopy]] or reflectance spectroscopy in part of the [[ultraviolet]] and the full, adjacent [[visible spectrum|visible]] regions of the [[electromagnetic spectrum]].<ref name=":1" /> Being relatively inexpensive and easily implemented, this methodology is widely used in diverse applied and fundamental applications.  The only requirement is that the sample absorb in the UV-Vis region, i.e. be a [[chromophore]]. Absorption spectroscopy is complementary to [[fluorescence spectroscopy]].  Parameters of interest, besides the wavelength of measurement, are absorbance (A) or transmittance (%T) or reflectance (%R), and its change with time.<ref name="PIA">{{cite book |last1=Skoog |first1= Douglas A. |first2=F. James |last2= Holler |first3= Stanley R. |last3= Crouch |title=Principles of Instrumental Analysis |url=https://archive.org/details/principlesinstru00dasc |url-access=limited |edition=6th |publisher=Thomson Brooks/Cole |location=Belmont, CA |year=2007 |pages=[https://archive.org/details/principlesinstru00dasc/page/n182 169]–173 |isbn=978-0-495-01201-6 }}{{Dead link|date=March 2024}}</ref><ref name="RSD" />

A '''UV-Vis spectrophotometer''' is an analytical instrument that measures the amount of ultraviolet (UV) and visible light that is absorbed by a sample. It is a widely used technique in chemistry, biochemistry, and other fields, to identify and quantify compounds in a variety of samples.<ref>{{Cite book |last1=Franca |first1=Adriana S. |title=Spectroscopic Methods in Food Analysis |last2=Nollet |first2=Leo M.L. |publisher=CRC Press |year=2017 |isbn= |pages=664}}</ref>

UV-Vis spectrophotometers work by passing a beam of light through the sample and measuring the amount of light that is absorbed at each wavelength. The amount of light absorbed is proportional to the concentration of the absorbing compound in the sample.