Method for detecting chemical substances

A method of identifying a chemical substance contained in a vapor phase comprising the steps of:

• (A) holding an electrolytic solution having a surface coming into direct contact with a vapor phase around electrodes;
• (B) obtaining a predetermined fitting function and parameters from a chemical substance selected as a reference substance, said step comprising the steps of:
• (b1) diffusing the chemical substance selected as the reference substance into the electrolytic solution;
• (b2) detecting an electric state at the electrodes existing in the electrolytic solution as a change with time based on the diffusion and absorption of the chemical substance on the electrodes and preparing a pattern of a change of the electric state with time;
• and
• (b3) setting a fitting function based on the pattern and finding parameters of the reference substance for the fitting function;
• (C) obtaining predetermined parameters from a chemical substance being measured, said step comprising the steps of:
• (c1) diffusing the chemical substance being measured into the electrolytic solution;
• and
• (c2) detecting an electric state at the electrodes existing in the electrolytic solution as a change with time based on the diffusion and absorption of the chemical substance on the electrodes and preparing parameters of the substance being measured for the fitting function;
• and
• (D) calculating a distance between the parameters of the reference substance and the parameters of the substance being measured and determining that the reference substance having the minimum distance therebetween is most similar to the substance being measured.