Table 2.

Extraction of Boltzmann parameters for the qγ charge from overall charge-voltage curves at different concentrations of caffeine assuming previously determined values for the parameters describing the qβ charge ^†

Experimental conditions	n	Qmax (nC μF−1)	V* (mV)	k (mV)
0 mm caffeine	7	11.3 ± 0.40	−53.5 ± 1.47	4.2 ± 1.08
0.2 mm caffeine	6	13.1 ± 0.69	−55.1 ± 1.14	5.4 ± 0.63
1.0 mm caffeine	6	12.6 ± 0.84	−54.9 ± 2.12	6.6 ± 0.99
5.0 mm caffeine	6	13.0 ± 0.47	−55.2 ± 1.36	7.0 ± 1.14

^†Q_max = 9.2 nC μF⁻¹

^*V = −37.14 mV; k = 14.08 mV (Huang, 1998).