Hey there! Sign in to join this conversationNew here? Join for free
    • Thread Starter
    Offline

    4
    ReputationRep:
    What is the function of an electric field in a time of flight mass spectrometer and how do you create positive ions?
    Offline

    2
    ReputationRep:
    (Original post by Jennifer50)
    What is the function of an electric field in a time of flight mass spectrometer and how do you create positive ions?
    High voltage is applied which cause the atoms to lose electrons, forming +ve ions. If I remember correctly, the electric fields cause the ions to accelerate.
    Offline

    14
    ReputationRep:
    (Original post by Jennifer50)
    What is the function of an electric field in a time of flight mass spectrometer and how do you create positive ions?
    The positive ions are formed after VAPORISATION of the sample.
    It is formed by the use of an electron gun (in the mass spectrometer) which shoots fast moving high energy electrons onto the atoms.
    This causes an electron to be removed from the atom.

    Electric field is needed to accelerate the ions that was produced
    • Thread Starter
    Offline

    4
    ReputationRep:
    Are the positive ions then dissolved in a volatile solvent?
    Offline

    14
    ReputationRep:
    (Original post by Jennifer50)
    Are the positive ions then dissolved in a volatile solvent?
    As I know,
    The answer for that is NO
    • Thread Starter
    Offline

    4
    ReputationRep:
    So esentially you apply heat to vaporise the sample, and then use an electron gun? But don't you have to dissolve the original sample in a volatile solvent and then use the electron gun?
    Offline

    3
    ReputationRep:
    The sample being investigated is first dissolved in a volatile substance and forced through a fine hollow needle which is connected to a positive terminal of high voltage. Which then produces tiny positive charged droplets which have lost electrons to the positive charge of the supply. These just produced positive ions are accelerate towards the negative charged plate. Lighter ions and more highly charged ions achieve a higher speed. The ions need to be produced so they can accelerate towards the negative plate and pick up an electron form the detector when they reach it, which causes a current to flpw :P. etc.etc.
    Offline

    14
    ReputationRep:
    (Original post by roxy1331)
    high voltage is applied which cause the atoms to lose electrons, forming +ve ions. If i remember correctly, the electric fields cause the ions to accelerate.
    hey hey )
 
 
 
  • See more of what you like on The Student Room

    You can personalise what you see on TSR. Tell us a little about yourself to get started.

  • Poll
    What's your favourite Christmas sweets?
  • See more of what you like on The Student Room

    You can personalise what you see on TSR. Tell us a little about yourself to get started.

  • The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

    Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE

    Quick reply
    Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.