Ads
related to: spectrophotometer high absorbance means that two points are given
Search results
Results from the WOW.Com Content Network
In UV-VIS, an isosbestic point is often interpreted as implying the occurrence of a single linearly independent reaction. The simplest examples of isosbestic points involve only two species, but isosbestic points do not imply the participation of only two species (e.g. the IUPAC example involves 5 species), which is a common misconception [1].
Single-beam scanning spectrophotometer. There are two major classes of devices: single-beam and double-beam. A double-beam spectrophotometer [13] compares the light intensity between two light paths, one path containing a reference sample and the other the test sample. A single-beam spectrophotometer measures the relative light intensity of the ...
The method or technique of infrared spectroscopy is conducted with an instrument called an infrared spectrometer (or spectrophotometer) which produces an infrared spectrum. An IR spectrum can be visualized in a graph of infrared light absorbance (or transmittance) on the vertical axis vs. frequency, wavenumber or wavelength on the
Parameters of interest, besides the wavelength of measurement, are absorbance (A) or transmittance (%T) or reflectance (%R), and its change with time. [4] [5] 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 ...
Absorbance is defined as "the logarithm of the ratio of incident to transmitted radiant power through a sample (excluding the effects on cell walls)". [1] Alternatively, for samples which scatter light, absorbance may be defined as "the negative logarithm of one minus absorptance, as measured on a uniform sample". [2]
Two other issues that must be considered in setting up an absorption spectroscopy experiment include the optics used to direct the radiation and the means of holding or containing the sample material (called a cuvette or cell). For most UV, visible, and NIR measurements the use of precision quartz cuvettes are necessary.
Variable pathlength absorption spectroscopy uses a determined slope to calculate concentration. As stated above this is a product of the molar absorptivity and the concentration. Since the actual absorbance value is taken at many data points at equal intervals, background subtraction is generally unnecessary.
The absorbance measured by the Spectronic 20 is the sum of the absorbance of each of the constituents of the solution. Therefore, the Spectronic 20 can be used to analyze more complex solutions. For example, if a sample solution has two light-absorbing compounds in it, then the user performs measurements at two different wavelengths and ...
Ads
related to: spectrophotometer high absorbance means that two points are given