UV-Vis spectroscopy

Ultraviolet-visible (UV-Vis) spectroscopy is a measurement technique that refers to the absorption of light in the UV-visible wavelength range of the substance in question. The UV region falls between 190-380 nm and the visible region lies between 380-750 nm. Each substance contains electrons that are capable of absorbing light of various wavelengths. The observed pattern of each substance is unique and thus detectable by the single absorbance peak (or range) at given wavelengths.

The machine used in NanoFASE is a diode array spectrophotometer (Agilent HP8453) which is capable of detecting all of the required wavelengths simultaneously. Other machines that have one single wavelength detector may require pre-setting to the desired wavelengths.

  • An aliquot of the sample of interest is placed in the cuvette, which is inserted into the spectrophotometer.
  • Light in the UV-Vis range is projected from the tungsten lamp (370-1100 nm) and deuterium lamp (190-800 nm), which is passed through the sample via the shutter and stray light filters.
  • Certain wavelengths of light are absorbed by the sample.
  • Light not absorbed passes through the sample and is projected by the spectrograph lens onto the diode array, which converts the signal into absorbance units over the wavelength range (i.e 190-1100nm).
  • Absorbance peaks represent maximum absorption at the given wavelength. For example, gold nanoparticles of 20 and 80nm absorb at wavelengths of approximately 523 and 550nm respectively.

Used in

 

Batch tests

Read more

Read also
 

NanoFASE Report D7.2 Soil property - NM Fate relationships

OECD (2017) OECD Guidelines for the Testing of Chemicals, Section 3. Test No. 101: UV-VIS Absorption Spectra Columns. http://dx.doi.org/10.1787/9789264069503-en

 

Contact

 

 

Jessica Adams

Centre for Ecology and Hydrology (CEH)

Email: jesams@ceh.ac.uk