Spettrometria di massa

• What is the primary purpose of mass spectroscopy?


  To identify the molecular weight of compounds.
• Why is mass spectrometry considered important in both organic and inorganic chemistry?


  It allows for the identification of molecular weight, which is crucial for understanding molecular structure.
• How does molecular weight provide information about the type of atoms in a molecule?

  Molecular weight can indicate the atomic composition of the compound.
• What advantage does mass spectroscopy have over elementary analysis?


  Mass spectroscopy provides information about any kind of atoms in a molecule, including metals.
• What is the role of ionization in mass spectroscopy?


  Ionization allows the molecule to acquire a charge, which is necessary for mass measurement.
• What happens to a molecule during the ionization process in mass spectroscopy?


  The molecule is given a charge through energy interaction, allowing it to be accelerated and analyzed.
• What is measured in mass spectroscopy?


  The ratio of mass to charge (m/z) of the ionized molecule.
• Why is it necessary to work under vacuum in mass spectrometry?


  To prevent the ionized molecules from reacting with other molecules in the air.
• What is the function of the mass spectrometer's inlet?


  It is where the sample is injected into the mass spectrometer.
• What are the main components of a mass spectrometer?


  Inlet, ionization chamber, ion transfer, analyzer, and detector.

  
• How does the ionization chamber function in a mass spectrometer?


  It facilitates the ionization of the sample through various ionization processes.
• What is the difference between hard and soft ionization techniques?


  Hard techniques use high energy and temperature, while soft techniques use lower energy to minimize fragmentation.
• What is electron ionization?


  A technique that uses an electron beam to ionize molecules.
• What happens to a molecule during electron ionization?


  The molecule can become a cation, anion, or radical depending on the interaction with the electron beam.
• What is the purpose of the positive plates in the ionization chamber?


  To select and repel radical cations during the analysis process.
• How does chemical ionization differ from electron ionization?


  Chemical ionization uses a reagent to ionize the molecule instead of directly ionizing the molecule itself.
• What is FAB in mass spectrometry?


  Fast Atomic Bombardment, a soft ionization technique that does not require gas-phase analysis.

  
• What is the role of caesium in FAB?


  Caesium is used to bombard the matrix and promote ionization without destroying the sample.
• What does MALDI stand for?


  Matrix-Assisted Laser Desorption/Ionization.

  
• How does ESI differ from other ionization techniques?


  ESI can introduce multicharge ionization of macromolecules through the transformation of drops.
• What is the difference between trap analyzers and linear analyzers in mass spectrometry?


  Trap analyzers are more sensitive and analyze samples over time, while linear analyzers require a continuous flow of material.
• What happens to ionized molecules in the acceleration chamber?


  They are accelerated by an electromagnetic field, with speed proportional to their molecular weight.
• What does the detector in a mass spectrometer measure?


  The number of specific ions present in the sample.
• Why is it important to control the potential of acceleration or the intensity of the magnetic field in mass spectrometry?


  To select specific molecules based on their mass-to-charge ratio.
• How does the ionization process affect the final molecules detected in mass spectrometry?


  The final molecules often contain more than one charge due to the ionization process.
• What is the significance of measuring the ratio m/z in mass spectrometry?


  It allows for the determination of the mass of the molecule.
• What is the role of the inert gas like helium in mass spectrometry?


  It serves as a carrier gas for the sample during analysis.
• How does the concentration of positive charge in ESI lead to the separation of molecules?


  When the concentration is too high, it causes an explosion, resulting in the separation of positively charged molecules.
• What is the maximum temperature in the capillary tube during the ionization process?


  40°C maximum.
• What is the purpose of the ion transfer component in a mass spectrometer?


  To transfer a portion of the ionized material to the next stage of analysis.
• How does the mass spectrometer analyze different molecular weights?


  By selecting specific molecular weights during the analysis process.
• What is the significance of the ionization technique used in a mass spectrometer?


  The ionization technique determines how effectively the sample can be analyzed based on its properties.
• What is the main function of the analyzer in a mass spectrometer?


  To separate ions based on their mass-to-charge ratio.
• What is the relationship between molecular weight and speed in the acceleration chamber?


  Speed is proportional to molecular weight; larger molecules move faster.
• How does the mass spectrometer ensure that only one size of molecule passes through the tube?


  By adjusting the magnetic field and potential of acceleration to select specific molecules.
• What is the significance of the mass spectrum profile?


  It provides information on molecular weight and structural details of the molecule.
• Why is it important to use an inert gas like helium in mass analysis?


  To prevent reactions with air and ensure accurate measurements.
• How does the ionization process affect the analysis of medium-sized molecules?


  It allows for the analysis of smaller quantities of sample, making it more efficient.
• What is the role of software in a mass spectrometer?


  To control all blocks of the instrument simultaneously.
• What is the importance of the ionization technique in mass spectrometry?


  It determines how effectively the sample can be ionized and analyzed.