Flame photometry sem 7

Flame photometry OR Flame Atomic Emission Spectrometry is a branch of spectroscopy in which the species examined in the spectrometer are in the form of atoms.

1. FLAME PHOTOMETRY UNIT - II Sakeena Fatima B.Pharmacy Year : IV Sarojini Naidu Vanita Pharmacy Maha Vidyalaya

2. Introduction Flame photometry or Flame Atomic Emission Spectrometry is a branch of spectroscopy in which the species examined in the spectrometer are in the form of atoms. Flam e P ho t ome t ry is b ased o n m easu r eme n t o f i n t ensity of the light emitted when a metal is introduced into flame. The wavelength of color tells what the element is (qualitative) The color's intensity tells us how much of the element present (quantitative)

3. BASIC CONCEPT Atoms of elements  subjected to hot flame  specific quantum of thermal energy absorbed by orbital electrons  become unstable at high energy level  release energy as photons of particular wavelength  change back to ground state.

4. When a metal salt solution is burned, the metal provides a colored flame, and each metal ion gives a different colored flame. Flame tests, therefore, can be used to test for the absence or presence of a metal ion

5. PRINCIPLE When a solution is aspirated into a low temperature flame, in an aerosol, each droplet of water evaporates leaving a solid core of the residue of evaporation. The core further breaks down to the molecular level, and provided the molecules are not too refractory, progress to form atomic species.  The atom then is excited by the flame and its electron temporarily moves to a higher energy state. • When the electrons return to the ground state, they lose the excitation energy, and a discrete wavelength of visible light is emitted. • The emitted light can be isolated from other light wavelengths by an optical filter. • The amount of light being emitted is proportional to the number of atoms in the flame, and it follows, the conc. of that atom in the original solution. • The amount of light emitted can be measured by a suitable photo detector. • A photo detector generates an electrical signal which is amplified and displayed on a digital readout.

6. INTERFERENCES

7. INTERFERENCES

8. INSTRUMENTATION

9. DIGITAL FLAME PHOTOMETER A photoelectric flame photometer is an instrument used in inorganic chemical analysis to determine the concentration of certain metal ions among them ,like sodium, potassium, calcium and lithium.

10. MAJOR COMPONENTS Sample Delivery System Monochromator Detector Read Out Device

11. SAMPLE DELIVERY SYSTEM

12. Monochromator A  monochromator  is an optical device that transmits a mechanically selectable narrow band of wavelengths of light or other radiation chosen from a wider range of wavelengths available at the input. The main function of a monochromator is to separate the color components of a light. PRISM: Quartz material is used for making prism, as quartz is transparent over entire region. GRATING: it employs a grating which is essentially a series of parallel straight lines cut into a plane surface

13. DETECTOR The wavelengths produced are monitored by a photo multiplier, amplified and turned into an electrical signal. These signals are detected by a detector.

14. READ OUT DEVICE

15. Applications • To estimate sodium, potassium, calcium, lithium etc. level in sample of serum, urine, CSF and other body fluids. • Flame photometry is useful for the determination of alkali and alkaline earth metals. • Used in determination of lead in petrol. • Used in the study of equilibrium constants involving in ion exchange resins. • Used in determination of calcium and magnesium in cement.