Host–Guest Extraction of Heavy Metal Ions with p-t-Butylcalix[8]arene from Ammonia or Amine Solutions

Table 1

Extraction percentage (Ex%) of the transition metal ions with H₈L from ethylene diamine into dichloromethane at 25°C and distribution ratio of M(en)₂ and M(en)₃ in the aqueous phase before extraction. Uncertainties are given in parentheses as standard errors of the mean (N = 3).

	%E	M(en)2	M(en)3
		(%)	(%)
Co(II)	0	0	100
Ni(II)	0	0	100
Cu(II)	97.0	100	40
Zn(II)	46.0	3	97
Ag(I)	52.7	99	35
Cd(II)	90.1	15	85

(en)₂ = ethylene diamine,(en)₃ = ethylene triamine.