Question 1:
Which of the following ionization techniques is commonly used in mass spectrometry?
Explanation: The correct answer is C) Electrospray ionization (ESI). Electrospray ionization is a commonly used ionization technique in mass spectrometry. It involves the generation of highly charged droplets of analyte molecules in a solvent under the influence of a high voltage. The solvent evaporates, leaving behind gas-phase ions that can be analyzed in the mass spectrometer. ESI is suitable for the ionization of a wide range of compounds, including peptides, proteins, and small molecules.
Question 2:
Which ionization technique involves the vaporization of the sample and ionization by a high-energy beam?
Explanation: The correct answer is B) Matrix-assisted laser desorption/ionization (MALDI). MALDI is an ionization technique commonly used in mass spectrometry. In MALDI, the sample is mixed with a matrix compound and applied to a solid surface. A high-energy laser beam is used to vaporize and ionize the sample, generating ions that can be analyzed in the mass spectrometer. MALDI is particularly suitable for the analysis of large biomolecules such as proteins and peptides.
Question 3:
Which ionization technique involves the bombardment of the sample with high-energy electrons?
Explanation: The correct answer is D) Electron impact ionization (EI). Electron impact ionization is an ionization technique commonly used in gas chromatography-mass spectrometry (GC-MS). In EI, the sample is vaporized and bombarded with high-energy electrons, resulting in the formation of positively charged ions. EI is particularly suitable for the analysis of volatile and semi-volatile compounds in gas chromatography, where the sample is introduced into the mass spectrometer after separation by GC.
Question 4:
Which ionization technique involves the reaction of analyte molecules with ions in the gas phase?
Explanation: The correct answer is C) Chemical ionization (CI). Chemical ionization is an ionization technique commonly used in mass spectrometry. In CI, the analyte molecules are ionized by reacting with ions in the gas phase generated from a reagent gas, such as methane or ammonia. The ion-molecule reactions result in the formation of new ions, which can be analyzed in the mass spectrometer. CI is particularly useful for the analysis of compounds with low volatility and high molecular weight.
Question 5:
Which ionization technique involves the ionization of compounds in an atmospheric pressure region?
Explanation: The correct answer is D) Atmospheric pressure chemical ionization (APCI). Atmospheric pressure chemical ionization is an ionization technique commonly used in mass spectrometry. In APCI, the sample is ionized in an atmospheric pressure region using a corona discharge or other ionization sources. APCI is particularly suitable for the analysis of semi-volatile and nonvolatile compounds, including polar and nonpolar analytes, in liquid chromatography-mass spectrometry (LC-MS).
- Click to Check the published quizzes on various Categories
- Click to Practice various fundamentals of PMP Certification
- Click to Check Published courses on Piping Engineering
- Click to check Video Liberary (with more than 600+ Videos)