Atomic Absorption Spectroscopy Flashcards

Flashcards about Atomic Absorption Spectroscopy (AAS) from a Food Analysis lecture.

What is spectroscopy?

The study of the interaction of electromagnetic radiation with matter.

What does AAS stand for?

Atomic Absorption Spectroscopy.

What is the fundamental principle behind AAS?

AAS is an analytical method based on the absorption of UV or visible light by gaseous atoms.

What does AAS determine?

AAS determines chemical elements quantitatively using the absorption of optical radiation (light) by free atoms in the gaseous state.

What is the purpose of atomization in AAS?

To separate particles into individual molecules and break molecules into atoms, converting the analyte into a gaseous state.

What are the two main types of atomizers used in AAS?

Flame AAS and graphite furnace AAS.

Which types of samples can be analyzed by flame AAS versus graphite furnace AAS?

Flame AAS can only analyze solutions, while graphite furnace AAS can analyze solutions, slurries, and solid samples.

What is the function of a nebulizer in flame AAS?

A nebulizer converts the sample into an aerosol (mist) that is fed into the burner.

What is the role of the hollow cathode lamp (HCL) in AAS?

It serves as a light source, emitting specific wavelengths that correspond to the element being analyzed.

What is the purpose of the monochromator in AAS?

To select the specific wavelength of light absorbed by the sample and to exclude other wavelengths emitted by the hollow cathode lamp.

What are the components of a monochromator?

A diffraction grating, slits, and spherical mirrors.

What is the function of the detector in AAS?

To convert light signals to electrical signals proportional to the light intensity.

What type of detector is typically used in AAS?

A photomultiplier tube.

What is the purpose of a blank reading in single beam spectrophotometers?

The absorbance is set to zero by taking a blank sample containing no analyte.

What is the relationship between absorbance and concentration in AAS?

The absorption of light is proportional to the concentration of the element present in the sample.

What is the Beer-Lambert Law?

It combines Beer’s and Lambert’s Laws, stating that absorbance is proportional to both the concentration and the thickness of the sample.

What is a calibration curve used for in AAS?

To determine the unknown concentration of an element in a solution by comparing it to standards of known concentrations.

Give examples of clinical analyses performed using AAS.

Analysis of metals in biological fluids like blood and urine (e.g., Ca, Mg, Li, Na, K, Fe).

How is AAS used in environmental analysis?

To monitor the levels of various elements in the environment, such as in rivers, seawater, and air.

Describe two food analysis applications of AAS.

Analyzing Sodium (Na) content in Kikkoman soy sauce and analyzing Iron (Fe) content in Irn-Bru beverage.