Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Experimental measurement of absorbance

The sequence of events in making a measurement with a spectrophotometer is as follows. [Pg.170]

The monochromator is set to the wavelength of measurement, the shutter is closed to prevent light reaching the detector, and the instrument is set to infinite [Pg.170]

The shutter is opened, the solvent (or blank ) is placed in the light path and the instrument is set to zero absorbance. The blank is usually just the solvent for the assay but, strictly speaking, should be everything in the sample matrix except the sample being measured. This means that in complex assays the blank solution has to be made up to match exactly the composition of the solvent/medium in which the sample will be measured, and has to be extracted or otherwise treated in exactly the same way as the sample. [Pg.171]

The sample solution (or test ) is placed in the light path and the absorbance is read directly by the instrument. [Pg.171]

The most important part of any spectroscopic assay is not the performance of the spectrophotometer (although the accuracy of the instrument is checked periodically). The crucial part of any experiment is the accurate preparation of the test and standard solutions. This often involves the accurate dilution of a stock solution using the volumetric glassware introduced in Chapter 6, namely the pipette and the volumetric flask. [Pg.171]


See other pages where Experimental measurement of absorbance is mentioned: [Pg.170]   


SEARCH



Experimental measurement

© 2024 chempedia.info