Atomic Spectrophometry Flashcards
Which statement best describes the principle of atomic spectrophotometry?
A. Interaction of molecules with infrared light.
B. Detection of ionized atoms in a plasma field.
C. Interaction of atoms with light to provide elemental identification.
D. Separation of compounds based on polarity differences.
C
Which of the following is NOT an application of atomic spectrophotometry in pharmacy?
A. Quantification of metallic impurities in formulations.
B. Detection of heavy metals in raw materials.
C. Structural elucidation of complex organic molecules.
D. Assay of alkali metals in infusion solutions.
C
What is the primary purpose of the flame in atomic absorption spectrophotometry (AAS)?
A. To excite atoms to higher energy states.
B. To ionize all atoms in the sample.
C. To volatilize and atomize the sample.
D. To measure the fluorescence of the sample.
C
What type of light source is used in AAS?
A. Hollow cathode lamp
B. Tungsten filament lamp
C. Mercury vapor lamp
D. Xenon flash lamp
A
Which factor can interfere with atomic spectrophotometry measurements?
A. Low sample viscosity
B. Use of distilled water as a solvent
C. Anionic interference from phosphate ions
D. Presence of inert gases like argon
C
In Atomic Emission Spectrophotometry (AES), the emission of light occurs when:
A. Electrons move from the ground state to the excited state.
B. Molecules vibrate in the presence of UV light.
C. Electrons return from the excited state to the ground state, emitting radiation.
D. Ions form covalent bonds with the flame
C
Which element would be most efficiently analyzed using flame AES?
A. Lead (Pb)
B. Sodium (Na)
C. Zinc (Zn)
D. Platinum (Pt)
B
Why is ionization suppression used in atomic spectrophotometry?
A. To enhance the emission of light from the sample.
B. To prevent excess ionization of analyte atoms, maintaining ground-state concentration.
C. To improve the viscosity of the sample solution.
D. To decrease the volatilization of metal atoms.
B
What is the purpose of the monochromator in AAS and AES?
A. To volatilize the sample in the flame.
B. To filter out unwanted wavelengths, isolating the wavelength of interest.
C. To provide a consistent flow of carrier gas.
D. To ionize the sample atoms for better detection
B
Which detector is used in both AAS and AES for detecting radiation intensity?
A. Photoionization detector
B. Thermal conductivity detector
C. Photomultiplier tube
D. Flame ionization detector
C
In AAS, why is the light source coated with the same metal as the element being analyzed?
A. To increase the ionization of the sample.
B. To ensure specific wavelengths are absorbed by the volatilized atoms.
C. To decrease the noise in the detector signal.
D. To allow analysis of multiple elements simultaneously.
B
How does plasma in ICP-AES improve sensitivity compared to flame AES?
A. Plasma heats the sample to higher temperatures, increasing atomization efficiency.
B. Plasma reduces the sample viscosity.
C. Plasma decreases the energy needed to excite electrons.
D. Plasma removes the need for a light source.
A
Which sample preparation method is common in atomic spectrophotometry?
A. Sonication in organic solvents.
B. Nebulization to create a fine aerosol mist.
C. Centrifugation of the sample solution.
D. Mixing with deuterated solvents.
B
What property of an atom is primarily measured in Atomic Absorption Spectroscopy?
A. Light emission
B. Light absorption
C. Electron diffraction
D. Heat conductivity
B
What is a common solution for reducing anionic interference in AES?
A. Adding excess potassium.
B. Using lanthanum chloride to precipitate anions.
C. Using a higher flame temperature.
D. Adding organic solvents to the sample.
B
