Mass spectrometry:

Mass spectrometry

is analytical technique, ions sorted into mass to charge ratio

Quantitative

calibration solutions analysed -> concentration of solutions (x axis) measured against counts per second(y axis) to give a calibration graph

Qualitative

can be analysed on a mass spectrometer to produce a mass spectrum (chart shows composition of solution)

5 steps

Calibration solutions only element being analysed (absorbance) over a range of concentrations plotted as a graph to read concentration of unknown sample

2.        Sample solution is drawn through thin tube turned into aerosol by a device (nebuliser)  then mixed with air and acetylene gases in a box called a spray chamber.

3.  spray is then forced upwards through to a burner where it is ignited-> undergoes desolvation, releasing atoms of the sample solution into the flame.

4. hollow cathode lamp(light), absorbed by the atoms released by the spray chamber. Measure and calaculate (absorbance).

 Explain what a mass spectrum is and how can it be used to identify components in a mixture.

Mass spectrum is a chart that representation of the mass-to-charge ratio showing the composition of the solution→ shown as percent abundance.

Identify components: (Quadrupole) rods deflect one type of ion toward the detector.

• All other ions are “vacuumed” out to waste.

 Describe the steps involved in mass spectrometry, namely the processes of ionisation, acceleration, deflection and detection.

Ionisation: removing the solvent and turning the atoms of the solution into ions.

• Plasma is at extremely high temperature (10000 kelvin).

• As the mist enters the plasma the liquid evaporates and all that is left is ions.

• The ions are focused using cones to form an ion beam.

Acceleration: driving the ions at speed towards the mass discriminator.

• The ion beam is then accelerated through a set of magnetic rods called a quadrupole.

Deflection: directing the ions needed for analysis toward the detector.

• The rods deflect one type of ion toward the detector.

• All other ions are “vacuumed” out to waste.

Detection: determining the number of ions of each isotope.

(electron multiplier.) = counts each ion as it comes out the other end and displays the results as a mass spectrum.

 Explain how a specific analyte (isotope) can be isolated for detection in a mass spectrometer.

By tuning the mass spectrometer to focus on the m/z ratio specific to atoms ions, you can isolate and detect this isotope from the mixture.