What is the flame photometer?
A flame photometer is a device that is used in inorganic chemical analysis for the determination of certain metal ions such as potassium, sodium, calcium, and lithium. The photoelectric flame photometry is based on determining the intensity of emitted light produced when a metal is introduced into a flame.
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Working principle of flame photometer:
The working principle of the flame-photometer is simple. The liquid is sprayed with a non-shiny flame in the form of a fine mist that is colored according to the characteristic emissions of the elements, e.g. Sodium (Na), Potassium (K), Calcium (Ca), and Lithium (Li). The flame is detected by a photodetector that observes the flame through a very narrow band optical filter that only passes the wavelength (nm) based on the characteristic emission of the chosen element.
The output of the photodetector is fed to electronic modules that provide digital readings of the desired element concentration. The method has to be calibrated with known concentrations of the solution, before testing the unknown liquid sample.
Compressed air is supplied to an atomizer in a measuring system with the aid of a compressor, leading to a draught of air at the tip of an atomizer, which is sucked in the mixing chamber sample fluid and into the mixing chamber. Liquid petroleum gas (LPG) is also used at a controlled pressure in the mixing chamber; here the atomized sample and gas are delivered to the burner and ignited.
The light from the flame is emitted by the optical lenses and transmitted to the flame photometer detector through a selected filter. The detector data analyzed electronically and the sample solution results are shown correctly.
Procedure of flame photometer:
Before beginning a working procedure of flame photometry, we must recognize the various components essential to perform the process. The flame photometer consists of four major components such as a source of flame, a nebulizer and mixing chamber, an optical filter, and a photodetector.
1. Source of flame: A burner delivered flame and can be maintained in a stable form and at a constant temperature.
2. Nebulizer and mixing chamber: This helps to move the sample solution of the molecules into a flame at a constant rate.
3. Optical filter (optical system): The optical system consists of three elements such as lens, filter, and a convex mirror. This separates the wavelength of any other extraneous emissions to be measured.
4. Photodetector: Detect the emitted light and determine the radiation level produced by the flame.
Working procedure of flame Photometer:
- Prepare standard and sample solutions as required
- Ensure the proper connection of the air, gas, and drain tube.
- Power the flame photometer and compressor according to the instruction manual
- Adjust the output pressure and drown the capillary tube into distilled water
- Turn on the gas supply and immediately ignite the flame.
- Set the blank with the diluent used for standard and sample preparation.
- Aspirate the standard samples sequentially.
- Aspirate the sample solution and record the readings.
- Do the device shutdown process.
Applications of flame photometer:
- The flame photometer determines the concentration of potassium (K), sodium (Na), and calcium (Ca) ions that are extremely significant for the activity of different metabolic functions in the human body.
- It is used for the qualitative and quantitative study of the components.
- The amount of various alkali and alkaline earth metals in the soil can be determined with the help of a flame test.
- It can be used for calcium determination from milk, drinks, beer, and other products.
- Flame photometry is used to determine the concentration of different elements and metals are in fruit juices, alcoholic beverages, and soft drinks.
- Flame photometry is used in pharmaceutical analysis.
Advantages of flame photometer:
- Flame photometry is a precise, fast, and responsive technique.
- This is a cost-effective technique compared with others.
- Qualitative and quantitative analysis of metal ions is possible using flame photometry.
- It does not require a specialist to handle it, as it is easy to operate
- Very low concentrations (PPM/PPB) of metal ions can be determined by this method.
Disadvantages of the flame photometer:
- The major disadvantage of flame photometry is it only analyzes the liquid sample.
- This technique does not provide details about the metal ion's molecular structure.
- This often requires calibration, in some cases, it takes longer to prepare the sample.
- The metal ion concentration can't be accurately measured using this method.
- Flame-photometry cannot analyze each metal atom.
Difference between a spectrophotometer and a flame photometer:
The major difference between the spectrophotometer and the flame photometer is that the spectrophotometer uses the absorption of light by the molecules in a sample., whereas the flame photometry makes use of a controlled flame test.
Frequently asked question (FAQ):
What is a flame photometer?
It is a spectrophotometer in which a mist of metal salts in solution is vaporized in a very hot flame and quantitatively evaluated by calculating the strength of the metal spectral lines.
What is the basic principle flame photometer?
The principle of flame photometry is based on determining the intensity of emitted light when a metal ion is introduced in a flame.
What type of spectroscopy is flame photometry?
It is a type of atomic spectroscopy used to determine the concentration of certain metal ions, for example, calcium, sodium, potassium, lithium, etc.
What is the major advantage of flame photometry?
Its major advantage is the analysis of alkali and alkaline earth metals by flame photometry.
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