WHAT IT IS
Sensitivity in flame AAS indicates how well the instrument can measure low levels of an element by assessing the amount of light absorbed by free atoms in a flame. Flame AAS typically detects concentrations in the parts per million (ppm) to parts per billion (ppb) range, depending on the element and instrument setup. Sensitivity is influenced by factors such as flame composition, burner design, and optical alignment.
HOW IT WORKS
Flame Atomization – A liquid sample is introduced into a flame, where it is desolvated, vaporized, and atomized to produce free atoms that absorb light at specific wavelengths.
Light Absorption Measurement – A hollow cathode lamp emits light at the target element’s wavelength, and the decrease in light intensity after passing through the flame is measured to determine the element’s concentration.
Flame Conditions – The type of flame (air-acetylene or nitrous oxide-acetylene) affects the temperature and efficiency of atomization, influencing sensitivity.
Optical System – Accurate alignment of the optical system ensures maximum light absorption and improves sensitivity.
IMPACT ON PERFORMANCE
Quantification of Trace Elements: Adequate sensitivity allows for the detection and quantification of elements at low concentrations in various samples.
Accuracy and Precision: High sensitivity ensures that even small changes in element concentration are accurately measured.
Fast Analysis: Flame AAS provides rapid analysis with sufficient sensitivity for many routine applications.
Sample Versatility: Sensitive flame AAS systems can analyze a wide range of sample types, including environmental, clinical, and industrial samples.
CHALLENGES AND LIMITATIONS
Lower Sensitivity Compared to Furnace AAS: Flame AAS is less sensitive than graphite furnace AAS, limiting its use for ultra-trace analysis.
Flame Instability: Variations in flame conditions can affect sensitivity and measurement accuracy.
Matrix Interferences: Complex sample matrices may reduce sensitivity due to chemical interferences in the flame.
Higher Detection Limits: Detection limits in flame AAS are higher compared to more advanced techniques, making it less suitable for very low-concentration