SPECTRO FLUORIMETRY Basics and Principle: Question with Answers

Fluorimetry is analytical method which is based on the absorbed or emitted radiation by the molecule. FLUORESCENCE :- when molecule absorbed incident electromagnetic radiation it is electron goes excited state. But in excited state it is unsatble so. Electron is goes ground state. When it is goes ground state it is emitted radiation. this phenomena called FLUORESCENCE.

Singlet ground state :- A state in which all the electron in a molecule are paried.

Doublet state :- A state in which an unpaird electron is present free radical.

Triplet state:- A state in which unpaird electron of same spin present.

Singlet excited state :- A state in which electron are unpaird but of opposite spin.

Phosphorescence :- At favourable condition like low temp. and absence of oxygen there is transition from excited singlet state to triplet state which is called as inter system crossing. The emissions of radiation when electron undergoes transition from triplets state to singlet ground state is called phosphorescence.

PRINCIPLE:-

‏The basic of fluorimetry Is the measurements of FLUORESCENCE.

Drug which are intrinsically fluorescent are determined fluorimetrically. EXAMPLE is Ergometrine in 1% tataric acid.

In fluorimetry radiation emitted are of longer wavelength than absorbed radiation.

This is because when the radiation fall on the molecule vibration occur during vibration period, loss of energy occur due to intra-molecular collision and some energy is lost of solvent molecule.

Hence, the emitted radiation are of longer wavelength and have less energy.

E=C/λ

MCQ.

1.A state in which all the electron in a molecule are paired ?

A. Singlet ground state

B. Doublet state

C. Triplets state

D. Singlet excited state.

Ans.A

2.A state in which an unpaired electron is present free radical?

A. Singlet ground state

B. Doublet state

C. Triplets state

D. Singlet excited state.

Ans. B

3. A state in which unpaired electron of same spin ?

A. Singlet ground state

B. Doublet state

C. Triplets state

D. Singlet excited state.

Ans. C

4. A state in which electron are unpaired but opposite spin

A. Singlet ground state

B. Doublet state

C. Triplets state

D. Singlet excited state.

Ans. D

5. when molecule absorbed incident electromagnetic radiation it is electron goes excited state. But in excited state it is unsatble so. Electron is goes ground state. When it is goes ground state it is emitted radiation. this phenomena called ?

A. FLUORESCENCE

B. Phosphorescence

C. A and B

D. None of this

Ans A

6. At favourable condition like low temp. and absence of oxygen there is transition from excited singlet state to triplet state which is called as inter system crossing. The emissions of radiation when electron undergoes transition from triplets state to singlet ground state is called ?

A. FLUORESCENCE

B. Phosphorescence

C. Collision

D. All of the above

Ans. B

7. Which sepctroscopy is measure intensity of the FLUORESCENCE of molecule?

A. IR

B. NMR

C. Flurometry

D. All of the above

Ans. C

8. When molecule are goes to excited state to ground state it is emitted radiation that wave length ?

A. Shorter than absorbed radiation

B. Longer than absorbed radiation

C. A and B

D. None of the

Ans. B

Reference take the book of pharmaceutical analysis thrid edition DR. S . RAVI SANKAR PAGE NO 3.2 -3.3