Spectrophotometric Determination of Cr(III) and Pb(II) Using Their Complexes with 5,11,17,23-Tetra[(2-ethyl acetoethoxyphenyl)(azo)phenyl]calix[4]arene

Table 1

Results obtained by the HPSMA for the analysis of Cr(III) and Pb(II) mixtures in different concentrations.

Samples	- equation		Present (10^−6 M)		Found (10^−6 M)
			Cr(III)	Pb(II)	Cr(III)	Pb(II)
X1	= 0.0103C + 0.1303; = 0.0171C + 0.1554	0.9993; 0.9991	4.00	4.00	3.70 ± 0.22	4.13 ± 0.32
X2	= 0.0103C + 0.1703; = 0.0171C + 0.2235	0.9992; 0.9989	8.00	4.00	7.75 ± 0.56	4.10 ± 0.35
X3	= 0.0102C + 0.2943; = 0.0170C + 0.4354	0.9995; 0.9982	20.00	4.00	20.57 ± 1.25	3.71 ± 0.29
X4	= 0.0103C + 0.2103; = 0.0171C + 0.2389	0.9995; 0.9995	4.00	8.00	4.20 ± 0.31	7.51 ± 0.62
X5	= 0.0104C + 0.4812; = 0.0169C + 0.5091	0.9995; 0.9978	4.00	20.00	4.29 ± 0.29	19.55 ± 1.75
	LOD; LOQ				1.3; 4.0	1.1; 3.4