Flame Photometer

A photoelectric flame photometer is a device used in inorganic chemical analysis to determine the concentration of certain metal ions, among them sodium, potassium, lithium, and calcium. Group 1 and Group 2 metals are quite sensitive to Flame Photometry due to their low excitation energies. Parts of a flame photometer

1. Source of flame: A burner that provides flame and can be maintained in a constant form and at a constant temperature.
2. Nebuliser and mixing chamber: Helps to transport the homogeneous solution of the substance into the flame at a steady rate.
3. Optical system (optical filter): The optical system comprises three parts: convex mirror, lens and filter. The convex mirror helps to transmit light emitted from the atoms and focus the emissions to the lens. The convex lens help to focus the light on a point called slit. The reflections from the mirror pass through the slit and reach the filters. This will isolate the wavelength to be measured from that of any other extraneous emissions. Hence it acts as interference type color filters.
4. Photo detector: Detect the emitted light and measure the intensity of radiation emitted by the flame. That is, the emitted radiation is converted to an electrical signal with the help of photo detector. The produced electrical signals are directly proportional to the intensity of light.

Applications:

Flame photometer has both quantitative and qualitative applications. Flame photometer with monochromators emits radiations of characteristic wavelengths which help to detect the presence of a particular metal in the sample. This help to determine the availability of alkali and alkaline earth metals which are critical for soil cultivation. In agriculture, the fertilizer requirement of the soil is analyzed by flame test analysis of the soil. In clinical field, Na+ and K+ ions in body fluids, muscles and heart can be determined by diluting the blood serum and aspiration into the flame. Analysis of soft drinks, fruit juices and alcoholic beverages can also be analyzed by using flame photometry.

Advantages:

1.Simple quantitative analytical test based on the flame analysis.
2.Inexpensive.
3.The determination of elements such as alkali and alkaline earth metals is performed easily with most reliable and convenient methods.
4.Quite quick, convenient, and selective and sensitive to even parts per million (ppm) to parts per billion (ppb) range.