Table 4.

Complex formation constants of thioglycolic acid, thiomalic acid, DMSA, DMPS, penicillamine, lipoic acid, dihydrolipoic acid with Hg²⁺, Cd^2+, and Pb²⁺. The pM values for each system are also reported in red.

	Hg2+		Cd2+		Pb2+
Ligand	Species	Logβ	Species	Logβ	Species	Logβ	Temp./Ion. Str.	Method
TGA	[186] HgL	34.5	[187] CdLH	11.08	[188] PbL	8.5	[186] 25, 0.1 M NaClO4	EMF
	HgL2	40.5	CdL	4.34			[187] 25, 3 M LiClO4	gl
			CdL2	6.49			[188] 25, 0.15 M	gl
pM	32.9		6.00		6.95
TMA	[189] HgL	9.94	[190] CdL	10.05	[181] PbL	10.80	[189] 25, 0.1 M KNO3	gl
	HgL2	18.07	CdL2	13.51			[190] 25, 0.2 M KNO3	gl
			Cd3L4	41.59			[181] 30, 0.007 ClO4−	gl
pM	8.24		7.78		8.90
DMSA	§	----	[181] CdLH3	28.73	[191] PbL	17.4	[181] 25, 0.1 M KCl	gl
			CdLH	23.50			[191] 25, 0.1 M	Spect.
			CdL	17.11
pM			11.48		11.45
DMPS	[192] HgL	42.2	[193] CdL2	28.27	[181] PbL	16.38	[192] 25, 0.1 M NaClO4	ISE
	HgL2	53.1	Cd3L3	59.9	PbL2	22.21	[193] 25, 0.2 M KNO3	gl
			Cd3L4	71.9			[181] 20, 0.1 KNO3	EMF
			Cd5L6	114.3
			Cd7L8	156.7
pM	37.60		13.24		12.00
	[181] HgL	39.71	[181] CdL	17.32			[181] 20, 0.1 KNO3	EMF
			CdL2H	35.19			[181] 37, 0.15 NaCl	gl
			CdL2	28.22
			Cd2L2	37.72
			Cd3L3H	61.91
pM	34.80		12.14
DPEN	[194] HgL	37.6	[190] CdL	11.53	[181] PbLH	15.87	[194] 25, 0.1 M KNO3
	HgL2H	52.31	CdL2	19.64	PbL	13.12	[190] 25, 0.2 M KNO3	gl
	HgL2	43.69	Cd3L4	50.22	PbL2H	26.19	[181] 25, 0.1 M KCl	gl
					PbL2	17.7
pM	34.50		8.61		10.50
	[186] HgL	37.8	[194] CdL	11.51			[186] 25, 0.1 M NaClO4	gl
	HgL2H	53.6	CdL2H	15.94			[194] 25, 0.1 M KNO3
	HgL2	44.50	CdL2	19.52
			CdL3	22.35
pM	35.30		8.46

§ Precipitation occurs [195].