Jennifer50
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What is the function of an electric field in a time of flight mass spectrometer and how do you create positive ions?
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Roxy1331
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(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.
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NNB_Herath
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(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
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Jennifer50
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Are the positive ions then dissolved in a volatile solvent?
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NNB_Herath
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(Original post by Jennifer50)
Are the positive ions then dissolved in a volatile solvent?
As I know,
The answer for that is NO
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Jennifer50
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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?
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Asad_2015
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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.
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NNB_Herath
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(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 )
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