Basic structure and characteristics of the hottest

  • Detail

Basic structure and characteristics of fluorescence spectrophotometer

1 Light source:

is a high-pressure mercury vapor lamp or xenon arc lamp, which can emit a continuous spectrum with high intensity, and the intensity is almost the same in the range of 300nm ~ 400nm, so it is commonly used

2. excitation monochromator:

the excitation monochromator or the first monochromator placed between the light source and the sample chamber is used to screen out the specific excitation spectrum

3. emission monochromator:

set the conditional yield limit or conditional yield strength between the sample chamber and the detector as the emission monochromator or the second monochromator, and the grating is often used as the monochromator. Select the specific emission spectrum

4. sample chamber:

usually consists of quartz pool (for liquid samples) or solid sample rack to protect the service life of the experimental machine (powder or sheet samples). When measuring liquid, the light source is arranged at right angles to the detector; When measuring solids, the light source is arranged at an acute angle with the detector

5. detector:

generally, photocell or photomultiplier tube is used as the detector. Optical signals can be amplified and converted into electrical signals

1. The fluorescence emission spectrum increases the safety of the product in the process of use

select a light excitation sample with a fixed wavelength, and record the functional relationship between the fluorescence emission intensity generated in the sample and the emission wavelength to obtain the fluorescence emission spectrum

2. fluorescence excitation spectrum

select a certain fluorescence emission wavelength and record the fluorescence emission intensity as a function of the excitation light wavelength to obtain the fluorescence excitation spectrum

3. time resolution technique

can be used to distinguish and measure the components with overlapping spectra but different lifetimes in the mixture

the time-resolved fluorescence measurement formula is as follows:

where p (T): fitting the exponential function

P0: intensity value

exp: exponential operator

t: time value

: average fluorescence time life

Copyright © 2011 JIN SHI