METHOD OF DETECTING ORGANIC MOLECULES Russian patent published in 2009 - IPC G01N27/62 

FIELD: chemistry.

SUBSTANCE: present invention relates to gas analysis and can be used for detecting vapours of organic compounds in air. The method of detecting organic molecules in air involves use of a surface-ionising source of ions of organic molecules to ionise a sample of organic molecules. Drift spectra of organic molecules are recorded at different values of amplitude of output voltage of a high voltage generator. For each peak on the drift spectra, the relationship between the maximum ion current and the value of output voltage of the high voltage generator is determined. From the obtained graphs, sections with linear relationship between peak ion current and output voltage of the high voltage generator are identified. From the number of linear sections on each graph of peak ion current on drift spectra versus the output voltage of the high voltage generator, the number of types of ions giving rise to the ion current peak on the drift spectra is determined. From the slopes of linear sections on each graph of peak ion current on drift spectra versus the output voltage of the high voltage generator, the types of ions giving rise to the ion current peak on the drift spectra are determined. For each peak of ion current on drift spectra only sections with gradually falling values of slopes are considered from the total number of sections with linear relationship between peak ion current on drift spectra from the value of output voltage of the high voltage generator. For each ion current peak on drift spectra, values of slopes of linear sections on graphs of peak ion currents on drift spectra versus output voltage of the high voltage generator are used for determining drift mobility of ions of organic molecules, giving rise to the peak of ion current on drift spectra, within the limits of low electric field intensity.

EFFECT: more accurate detection of organic compounds.

3 cl, 2 dwg