METHOD OF SEPARATING AND DETECTING IONS IN GAS (VERSIONS) Russian patent published in 2013 - IPC G01N27/62 

FIELD: physics.

SUBSTANCE: in the method, involving separation of ions of different types by superposition of alternating-sign periodic homogeneous or heterogeneous polarity asymmetrical and symmetrical electric fields and a unidirectional electric field in a gas stream, bound by extended electrodes, varying the unidirectional electric field, conveying the separated ions using the gas stream for detection, recording the spectrum of the separated ions in form of a set of ion peaks, including ions of controlled substances, according to the first version of the invention, in the entire temperature range of the gas without the alternating-sign periodic polarity-symmetrical electric field, parameters are determined, which characterise mean-square deviation (MSD) of peaks of controlled substances; then while varying the unidirectional electric field and recording the spectrum, gas temperature is measured, and the amplitude of the strength of the alternating-sign periodic polarity-symmetrical electric field when recording each section of the spectrum where a peak of the controlled substance may exist, with a fixed period, is selected depending on the value of the parameter which characterises MSD of that peak at that temperature, based on the condition that: the higher the value of the parameter which characterises MSD of the peak, the higher the amplitude of the alternating-sign periodic polarity-symmetrical electric field when recording a section of the spectrum on which that peak may exist. According to the second version, the period of the alternating-sign periodic polarity-symmetrical electric field, at fixed amplitude of field strength, is selected depending on the value of the parameter which characterises MSD of that peak at that temperature, based on the condition that: the higher the value of the parameter which characterises MSD of the peak, the longer the period of the alternating-sign periodic polarity-symmetrical electric field when recording a section of the spectrum on which that peak may exist.

EFFECT: invention increases stability of such analytical characteristics as sensitivity, resolution and selectivity for a selected list of controlled substances in the entire gas temperature range.

6 cl, 6 dwg