mass spectrometry

To measure the mass of an atom, we use a…

mass spectrometer

Which of these are stages in time of flight mass spectrometry? (4)

Ionisation

Ion drift

Acceleration

Detection

After ions are detected by the mass spectrometer, the computer produces a…

• mass spectrum

The x axis label of a mass spectrum is…

mass to charge ratio

Use the mass spectrum below to calculate the relative atomic mass of mercury.

Total ions: 30+51+69+39+90+21=300

Hg¹⁹⁸:30/300 ×100=10 percent

Hg¹⁹⁹:51/300 ×100=17 percent

Hg²⁰⁰:69/300 ×100=23 percent

Hg²⁰¹:39/300 ×100=13 percent

Hg²⁰²:90/300 ×100=30 percent

Hg²⁰⁴:21/300 ×100=7 percent

Ar=200.6

A sample of ruthenium is analysed by time of flight mass spectrometry and the data is shown in the table below.

Identify the ion that reaches the detector first.
Give the correct representation of ion with charge.

⁹⁹Ru⁺

The ion with the smallest mass / charge ratio travels the fastest. So, 99Ru+ reaches the detector first

A sample of ruthenium is analysed by time of flight mass spectrometry and the data is shown in the table below.

Identify the ion that produces the largest electrical current at the detector.

Give the correct representation of ion with charge.

¹⁰²Ru⁺

The most abundant ion generates the largest electrical current at the detector. This is 102Ru+.

A sample of ruthenium is analysed by time of flight mass spectrometry and the data is shown in the table below.

Suggest the identity of the ion that produces a low-abundance signal at m/z=51

Give the correct representation of ion with charge.

¹⁰²Ru²⁺

Double ionisation of 102Ru generates a rare 102Ru2+ ion with a mass/charge ratio of 102/2=51.