Application of mass spectrometers in medicine

For medical applications, the Scientific Instruments JSC company has developed portable mass spectrometers "Micropor" and "Micropor-M" with membrane sample introduction.

The mass spectrometers are designed for:

  - Determination of toxic substances in the rapid diagnosis of poisoning based on the analysis of the composition of exhaled air

  - Analysis of the gas mixture in the breathing circuit of the inhalation anesthesia machine during surgical operations

  - Determination of drugs in biological fluids

The mass spectrometers are based on a quadrupole mass analyzer with a mass number measurement range from 1 to 300 amu. The analyzer rods are 100 mm long. The instruments use a closed electron impact ion source. Ion detection is carried out by a secondary electron multiplier (SEM).

The mass spectrometers provide continuous spectrum scanning in a given mass range, and also real-time trend analysis of substances with continuous measurement of selected spectral peaks.

The working pressure in the vacuum chamber during the analysis is about 10^-5 mm Hg. The sample introduction unit is equipped with an internal shut-off valve that allows the membrane to be changed without breaking the vacuum in the instrument. To increase the threshold sensitivity of the instruments, a "direct" introduction of the analyzed gas from the membrane into the region of the ion source is used.

The sample is introduced through a hydrophobic selective membrane that has increased permeability to organic gas components of microimpurities of the analyzed medium (air or liquid).