Calculation of Free Nicotine by Determination of pH and Nicotine in Tobacco

Characterizing nicotine delivery from tobacco products is important in the understanding of their addictive potential. Most previous studies report total nicotine and have not differentiated between nicotine in its protonated or free-base form. The amount of free nicotine calculated by determining pH and nicotine contents. The pH and nicotine contents in smokeless tobacco product, tobacco products and tobacco leaves were analyzed by Health Canada-Official Method T-310 and CORESTA Recommended Method N°62. The content of free nicotine was calculated according to the Henderson-Hasselbalch equation and the value of α∧fb(the fraction of nicotine that is in the free base form) by using a pKa value of 8.02 for nicotine.