Abstract: Based on the study of the reaction between 7,7,8,8-tetracyanoquino-dimethane(TCNQ) and nicotine in tobacco, a new method for determining nicotine in tobacco under optimized condition is proposed in this paper. Through the pr oposed method, the following results are obtained. The apparent molar absorptiv ity of the CT complexes at 743 nm is 4.84×10³ L·mol^－１ ·cm^－１, and the apparent molar absorptivity of the CT complexes at 842 nm is 8.82×10³ L·mol ^－１·cm^－１. In the prese nce of ethanol, Beer's law is obeyed in the range of 3~35 mg/L for nicotine. The relative standard deviation is 1.4%(n=9). The recovery is 98%～103%. The proposed method has been proved to be asimple, sensitive and reprodu cible method for the determination of the nicotine in ethanol with satisfactory results.

Key words: nicotine, 7,7,8,8-tetracyanoquinodimethane, charge transfer reaction, spectrophoto-metric method