Question about Mass spectrometer

Mass spectrometer is an apparatus used in exercise physiology to measure the composition of respired gases. In the fixed collector type of mass spectrometer, samples of gases are ionized, accelerated by an electric field, and, because the directions taken in this field depends on the mass of the ions, the fractions of oxygen, nitrogen, and carbon dioxide in the gas can be measured. The technique, known as mass spectrometry, is also used in dope testing to analyse the chemicals in a urine sample.

If the sample is not vaporized, how can it be 'accelerated by an electric field' and 'changing directions in this field depends on the its own mass (of the ions or molecular ions), ionization of the sample is for its ions to react with the applied electric field.

I hope this can help your understanding. :)

When in vapor form less sample is needed for the detection.