Ultraviolet & flourescence spectroscopy instrumentation

this ppt contains the instrumentational aspects of ultraviolet and luminiscence spectroscopy

1. UV-VIS and FLOURESCENCE INSTRUMENTATION

2. WE ARE GOING TO EXPLORE: UV-VIS Instrumentation aspects of FLOURESCENCE PHOSPHORESCENCE

3. UV-VIS INSTRUMENTATION

4. Single beam UV-VIS spectrophotometer D ouble beam UV-VIS spectrophotometer chem .iit bombay Indiamart.com

5. UV-VIS INSTRUMENTATION LIGHT SOURCE MIRRORS MONOCHROMATOR BEAM SPLITTER* SAMPLE CELLS / CUVETTES DETECTOR AS SIMPLE AS THAT

6. LIGHT SOURCE Commonly used light sources in UV-VIS spectrophotometers deuterium discharge lamp : UV region( 150nm-400nm) tungsten filament lamp : VIS region (250nm-800nm) Requirements of an Ideal light source: 1)It should emit light of continuous spectrum of uniform intensity over the region of interest. 2)The raduation generated by the source should be reproducible over time and continuous use . 3)It should provide incident light of sufficient intensity for the transmitted energy to be detected at the end of the optical path .

7. Jd.com Tuopeek.com Tunsten halogen lamp Deuterium discharge lamp

8. MONOCHROMATOR Shimadzu.com Azo optics.com Monochromator is a device used to isolate the monochromatic light of desired wavelength from polychromatic radiation. Commonly used monochromators are: 1)Filters 2)Prisms 3)Gratings

9. An ideal monochromater should possess: 1)high peak transmittance 2)low band pass absorption filters Filters interference filters refractive type prisms reflective type Gratings are preferred over prisms because they are resistant to moisture and also because of their low band pass of 0.1nm. Also there is no energy loss due to absorption in gratings.

10. CUVETTES Appleton woods.co.uk Glass cuvettes start absorbing in uv range and therefore used for studies in visible region. Quartz cuvettes or fused silica cells are used in uv spectral range studies. Care to be taken in handling and cleaning of cuvettes.

11. DETECTOR ifm.liu.se Detector is a device which converts the light energy in to electrical signal which will be fed in to a recording device Commonly used detectors are: 1)Barrier layer cell/photovoltaic cell 2)Photo emissive cell 3)Photomultiplier tube 4)Diode array detector

12. PHOTO DIODE ARRAY DETECTOR globalsino.com

13. BEER-LAMBERT’S LAW Beer-Lambert law states that the intensity of the absorbed light is directly proportional to the concentration of the sample and the path length. A=Ꜫcl where A= absorbance (dimensionless) Ꜫ= molar absorptivity (cm.mole/lit.) c= concentration of the sample (mole/lit.) l= path length (cm) Ꜫ=A/cl Molar extinction coefficient is the amount of light absorbed by a substance w hich is at a particular concentration.

14. CAN U HELP ME REACH THE DETECTOR?

15. UV-VIS INSTRUMENTATION BLOCK DIAGRAM LIGHT SOURCE MIRRORS MONOCHROMATOR RECORDER SAMPLE TUBE(S) DETECTOR BEAM SPLITTER

16. DOUBLE BEAM –IN SPACE SPECTROPHOTOMETER mientayvn.com

17. DOUBLE BEAM –IN TIME SPECTROPHOTOMETER Chemguide.in

18. Differences b/w single and double beam spectrophotometers: Number of beams Reliable absorbance values 3 ) High quality components Handling voltage fluctuations Handling time dependent irregularities 4 ) Complexity of instrument 5 ) Speed

19. APPLICATIONS In calculation of Molar absorptivity (Ꜫ) of a substance Detection of functional groups In Dye degradation studies Detemination of unknown concentration using calibration plot In Ion sensing studies ( e.g. fluoride sensing)

20. LUMINISCENCE FLOURESCENCE PHOSPHORESCENCE CHEMILUMINISCENCE BIOLUMINISCENCE ………………