7.1.1 Principles of Mass Spectrometry

    Cards (63)

    • Match the fragment with its mz\frac{m}{z} value:

      Methyl ↔️ 15
      Ethyl ↔️ 29
      Hydroxyl ↔️ 17
      Carbonyl ↔️ 28
    • If the molecular ion peak is at mz=\frac{m}{z} =72 72, what is the molar mass of the molecule?

      72 g/mol
    • The molecular ion peak is crucial for determining the molar mass of the compound.
    • What is the purpose of mass spectrometry?
      Determine mass-to-charge ratio
    • Each ion in mass spectrometry is characterized by its \frac{m}{z} value.
    • The five main stages of mass spectrometry in the correct order
      1️⃣ Ionization
      2️⃣ Acceleration
      3️⃣ Deflection
      4️⃣ Detection
      5️⃣ Analysis
    • In mass spectrometry, ionization converts molecules into ions.
    • How does electron impact ionization work?
      High-energy electron bombardment
    • Electrospray ionization is ideal for large biomolecules due to minimal fragmentation.
    • Electron impact ionization produces extensive fragmentation patterns.
    • What is a disadvantage of electrospray ionization?
      Requires a liquid sample
    • Match the ionization technique with its fragmentation level:
      Electron Impact (EI) ↔️ Extensive
      Electrospray Ionization (ESI) ↔️ Minimal
    • Mass spectrometry can be used to identify molecular mass and elucidate molecular structure.
    • What accelerates ions in mass spectrometry?
      Electric field
    • In mass spectrometry, ions are deflected according to their \frac{m}{z} ratio.
    • The detection stage in mass spectrometry measures ion abundance.
    • What is the equation for electron impact ionization?
      M + e^ - \rightarrow M^ + + 2e^ -</latex>
    • What are the two main ionization techniques in mass spectrometry?
      EI and ESI
    • Electron Impact (EI) uses high-energy electrons to bombard the sample, causing ionization and fragmentation
    • Electron Impact (EI) provides strong fragmentation patterns useful for structural elucidation
    • What type of ionization is ideal for large biomolecules?
      Electrospray Ionization (ESI)
    • Electrospray Ionization (ESI) is a gentle ionization method that causes minimal fragmentation
    • Electrospray Ionization (ESI) requires a liquid sample for ionization
    • Outline the process of ion separation in mass spectrometry
      1️⃣ Ions are accelerated through an electric field
      2️⃣ Ions achieve uniform kinetic energy
      3️⃣ Ions pass through a magnetic field
      4️⃣ Ions deflect based on mz\frac{m}{z}
      5️⃣ Ions are detected individually at the detector
    • What do detectors in mass spectrometry measure?
      Ion abundance
    • Match the detector type with its principle of operation:
      Electron Multiplier ↔️ Incident ion releases electrons that are multiplied
      Faraday Cup ↔️ Converts ion charge into measurable current
      Microchannel Plate ↔️ Uses multiple channels to multiply signals
    • Electron Multipliers in mass spectrometry are known for their high sensitivity and fast response
    • In a mass spectrum, the abundance of ions is represented on the y-axis
    • What does the molecular ion peak in a mass spectrum represent?
      Molar mass of the compound
    • Fragment ions in a mass spectrum arise when the molecular ion breaks apart
    • A significant peak at \frac{m}{z} = 57</latex> in a mass spectrum of a compound with mz=\frac{m}{z} =86 86 indicates the loss of a C2H5C_{2}H_{5} group
    • What is the primary purpose of mass spectrometry?
      Determine mz\frac{m}{z}
    • Describe the five main stages of mass spectrometry in order
      1️⃣ Ionization
      2️⃣ Acceleration
      3️⃣ Deflection
      4️⃣ Detection
      5️⃣ Analysis
    • Match the stage of mass spectrometry with its function:
      Ionization ↔️ Converts molecules into ions
      Acceleration ↔️ Provides uniform kinetic energy
      Deflection ↔️ Separates ions by mz\frac{m}{z}
      Detection ↔️ Measures ion abundance
    • The two main ionization techniques in mass spectrometry are Electron Impact (EI) and Electrospray Ionization (ESI)
    • In ion separation, lighter ions with higher charge deflect more than heavier ions with lower charge
    • What does the x-axis in a mass spectrum represent?
      mz\frac{m}{z} ratio
    • What does the y-axis of a mass spectrum represent?
      Relative abundance
    • A mass spectrum is a graphical representation of the mass-to-charge ratios (mz\frac{m}{z}) of ions plotted against their relative abundances
    • The molecular ion peak in a mass spectrum is used to determine the molar mass of a compound.
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