Table 1.

The association constants K_ass of Cd²⁺–ACAQ (5 µM) and L-cysteine in different solvents.

solvent systema	Kass (M−1)	R2
DMSO:HEPES = 8:2	(6.42 ± 1.56) × 104	0.9962
MeOH:HEPES = 8:2	(0.39 ± 0.24) × 104	0.9715
EtOH:HEPES = 8:2	(2.50 ± 0.68) × 104	0.9860
ACN:HEPES = 8:2	(1.20 ± 0.30) × 105	0.9790
ACN:HEPES = 5:5	(0.42 ± 0.12) × 104	0.9923
ACN:HEPES = 2:8	(0.66 ± 0.03) × 104	0.9977

^aHEPES in 10 mM at pH 7.4.