Fluorimetric Analysis

Absorption of energy

Emission of energy

Spectroscopy

Absorption of energy

Electronic transition UV/Visible

VibrationIR

Rotationmicrowave

Emission of energy

Flame emission Photoluminescence

Photoluminescence

FluorescenceThe excited molecule

returns to the ground state immediately after excitation

and vibration relaxation

PhosphorescenceThere is a time delay

between the excitation and returning to the ground

state after vibration relaxation

Fluorimetric Analysis : method of chemical analysis in which a sample,

exposed to radiation of one wavelength, absorbs this radiation and reemits radiation of the same or longer wavelength ,the intensity of reemited radiation is almost directly proportional to the concentration of the fluorescing material. Also known as fluorescence analysis; fluorometry.

Flurometer Spectrophotmeter

Source of light Xenon arch lampOr Hg vapor lamp-Perpendicular to sample

-Tangeston.-Deturium- Stright line.

Detector -Two monochromator-Very sensitive

- One monochromator

Sample Cell -Cuvette completely transberent - cell compartment is painted blank

- Only two side transperent

Comparison

Objectives:1- Determination of excitation and emission spectra of

Quinine SO4.

2- Prepare of calibration curve of Quinine SO4.

3-Determination of Concentration of unk. Quinine SO4 solution.

4-Demonstrate Quenching effect of KI on flourescence of quinine SO4.

Quenching effect

What does it mean by Quenching ?Quenching refers to any process which

decreases the fluorescence intensity of a given substance.

Quenching may occur by several mechanism:

collisional or dynamic quenching static quenching quencing by energy transfer charge transfer reactions

Quencher

• Chemical Quencher as alkali halide

• Self Quenching ??