Flame Photometry

Presented By :- Raghav Sharma
Class :- M. Pharm, 1st sem.
Department :- Pharmaceutics
Institute :- Parul Institute of Pharmacy


Content :-
Instrumentation and working of flame photometry
Flame atomizer
Nebulizer
Atomizer burner
Monochromator
Detector
Amplifier
Advantages
Disadvantages
Reference

1. Flame photometry Presented by : raghav Sharma M-pharm 1 st sem. (pharmaceutics ) P aRUL INSTITUTE OF Pharmacy 1

2. Content: Instrumentation and working of flame photometry Flame atomiser Nebuliser Atomiser burner Monochromator Detector Amplifier Advantages Disadvantages Reference 2

3. Flame photometer: Instrumentation 3

4. Procedure Transfer 2,4,6,8,10 ml of given standard Nacl solution in to 25ml standard in the 25ml standard flasks and dilute up to the mark with distilled water and shake well for uniform concentration . To the given unknown solution also, add distilled water and shake well Place the suction capillary of the instrument in distilled water and set the instrument to zero . Place the suction capillary in the given Nacl solution and set the instrument to 100. 4

5. . Place each of the standard solution in contact with the suction capillary and read the flame emission intensity for 2,4,6,8,10ml solution respectively (rinse the suction capillary with distilled water between each reading ) Place the suction capillary in the test solution and record the flame emission intensity . Draw a calibration curve by plotting the emission intensity vs volume of Nacl solution From the calibration cure find out the volume of given test solution and from which , calculated the amount of sodium in the water sample. 5

6. Instrumentation and working: Flame atomiser : It converts the sample into excited atomic species. Nebuliser and mixing chamber : It is a means of transporting a homogeneous solution into the flame at a steady rate . Atomiser burner : Here the fuel and oxidant burn to give a flame that can be maintained in a constant form and at a constant temperature. Monochromator (or filter ): It isolates the light of the wavelength to be measured from that of extraneous emissions. Detector : It helps in measuring the intensity of radiation emitted by the flame. Amplifier and Readout Device : It is used to amplify the signal and provides a suitable output. 6

7. Flame Atomiser The role of atomiser is to generate the vapours of analyte which get excited by the thermal energy of the flame and then emit characteristic radiation that is measured . The flame atomiser assembly consists of two components. The prior is a nebuliser where the sample in the form of a solution is drawn in and converted into a fine mist or an aerosol . It is then passed onto the second component i.e. the burner along with air or oxygen and a fuel gas. Nebulizer is a device used for sample introduction into the flame. The process is called nebulisation and consists of thermal vapourisation and dissociation of aerosol particles at high temperatures producing small particle size with high residence time. 7

8. Atomiser Burners The sample is introduced in the form of a fine spray at a controlled rate into the flame of a burner with the help of nebulizer. In the burner, the analyte undergoes a number of processes as mentioned earlier. two types of atomisation burners have been used in flame photometry . a ) Total consumption burner b) Pre-mix or laminar-flow burner 8

9. Monochromator Generally a grating or a prism monochromator is employed. The role of the monochromator is to disperse the radiation coming from the flame and falling on it. The dispersed radiation from the exit slit of the monochromator goes to the detector. Filters are generally made from materials which are transparent in a small selective wavelength region. The filter chosen is one which has a wavelength range in which it is transparent to emission from the element of interest. In such a case, a condenser lens system is employed to collect the emitted light and send the rays through the filter as an approximately collimated (parallel) beam to reach the detector. Filters have been designed for use in the determination of lithium, sodium, potassium, calcium and other elements. 9

10. P rism Prism is made from glass ,quarts or fused silica. When white light is passed through glass prism, dispersion of polychromatic light in rainbow occurs. now by rotation of the prism different wavelengths of the spectrum can be pass through in exit slit on the sample. The effective wavelength depends on the dispersive power of prism material and the optical angle of the prism. There are two type of mounting in an instrument Cornu type Littrow type 10

11. G rating Are most effective one in converting a polychromatic light to monochromatic light. They are commonly used in spectrophotometer Grating are two type: 1 . Diffraction grating : more refined of light is obtained by means of diffraction grating. 2. Transmission grating : refraction produced reinforcement. This occurs when radiation transmitted through grating reinforces with the partially refracted radiation. 11

12. D etector The function of a detector is to measure the intensity of radiation falling on it . Photoemissive cells or photomultiplier tubes are commonly employed for the purpose. These detectors are also used in UV-VIS spectrophotometers 12

13. Advantages of flame photometer The method of analysis is very simple and economical . It is both and qualitative, selective and sensitive analysis . It is quick, convenient, selective and sensitive analysis . Even very low concentration of metals in the sample can be determined. 13

14. Disadvantages of flame photometer Only liquid sample may used, also sample preparation becomes lengthy in some cases. Flame photometry cannot be used for the direct determination of each and every metal atom. The elements such as carbon, halides and hydrogen cannot be detected due to their non-radiating nature. 14

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16. Reference Vogel's textbook of quantitative chemical analysis by Arthur vogel and john mendham ; 5 th edition; page no:783to786 Instant notes on analytical chemistry by D.Kealey and P.J Haines: page no: 207-208. Chatwal and Anand; instrumental method of chemical analysis, Himalaya publishing house. Page no:370-375. 16

17. . THANK YOU 17