. 2022 Jun 23;7(27):23061–23068. doi: 10.1021/acsomega.2c00089

Table 1. Content Distribution of Three Forms of Nicotine in Aqueous Solution^a.

pH	free nicotine (%)	single-proton nicotine (%)	double-proton nicotine (%)
4.5	0.04	95.69	4.27
4.8	0.08	97.73	2.19
5.0	0.13	98.48	1.39
5.5	0.42	99.13	0.44
6.0	1.33	98.53	0.14
6.5	4.09	95.87	0.04
7.0	11.89	88.10	0.01
7.5	29.90	70.10	0.00
8.0	57.43	42.57	0.00

Note: pK_b1 = 3.15 and pK_b2 = 7.87, as used in the calculation.

Table 1. Content Distribution of Three Forms of Nicotine in Aqueous Solutiona.