atomic emission Flashcards
What is atomic emission spectroscopy (AES) used for in pharmaceuticals?
Quantifying alkali metals, detecting metallic impurities, and supporting drug development and quality control.
What are two main techniques in atomic emission spectroscopy?
Flame Photometry (FP) for alkali metals and Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES) for broader applications.
How does flame photometry work in AES?
Atoms in a flame are thermally excited and emit light at characteristic wavelengths as they return to ground state.
How does an ICP torch work in atomic emission?
It produces a high-temperature plasma (up to 10,000 K) by ionizing argon gas with radio-frequency energy, efficiently exciting atoms for emission.
What are the advantages of ICP-OES?
Simultaneous multi-element analysis, low detection limits, high precision, and wide dynamic range.
What is “spectral line width” in atomic spectroscopy?
The narrow range of wavelengths emitted by atoms, allowing high specificity and reducing spectral overlap.
What are sources of interference in atomic emission spectroscopy?
Ionization interference, spectral overlap, chemical interferences from low-volatility compounds, and matrix effects from physical properties of the sample.
How does the standard addition method help in AES?
It corrects for matrix effects by adding known increments of standard to the sample, allowing accurate concentration determination.
What is “matrix effect” in atomic emission spectroscopy?
Interference caused by sample components (e.g., excipients) that affect sample aspiration and nebulization rates.
How is “standard addition” used to counter matrix effects?
Known amounts of standard are added to the sample, and results are extrapolated on a graph to improve accuracy.
Why is the emission line width in atomic spectroscopy narrow?
Atomic emission lines are less than 0.01 nm wide, reducing spectral overlap and improving specificity.
