Flame photometry instrumentation involves several key components, each of which has a specific function that allows for the introduction of the sample, its atomization and excitation, and the subsequent measurement of the emitted light.
Here's a breakdown of the main components and their roles:
1. Sample Introduction System:
Nebulizer: It converts the liquid sample into an aerosol.
Spray Chamber: Ensures that only fine droplets make their way to the flame. This helps in achieving a consistent sample introduction and removes larger droplets that might not be atomized efficiently.
2. Flame Burner:
This is where the atomization and excitation of the sample take place.
The type of flame used (e.g., air-acetylene, nitrous oxide-acetylene) can vary based on the specific elements being analyzed and their optimal excitation conditions.
3. Monochromator:
After the sample is atomized and the metals are excited in the flame, they emit light at characteristic wavelengths.
The monochromator serves to select the specific wavelength of interest, filtering out other wavelengths. This can be a prism or a diffraction grating.
4. Detector:
Typically a photomultiplier tube (PMT) or a photodiode.
It detects the light passed through the monochromator and converts it into an electrical signal.
The intensity of this signal is proportional to the concentration of the element in the sample.
5. Readout System:
The detector's electrical signal is sent to a readout system (often a computer or digital display) that interprets the signal and provides a quantitative measurement, usually after comparing it to calibration data.
6. Flame Exhaust System:
Given that the process involves flames, there's a need for an exhaust system to handle any potentially hazardous fumes or gases produced during the analysis.
7. Power Supplies and Controls:
These ensure that each component functions correctly, providing power and enabling the user to make necessary adjustments for optimal performance.