Table 2.

QSPR model parameters for copper, cadmium and lead.

		Slope	RMSE	R2
Cu2+	calibration	0.86	4.29	0.86
	validation	0.64	6.88	0.66
Cd2+	calibration	0.91	2.85	0.91
	validation	0.76	4.22	0.81
Pb2+	calibration	0.95	2.60	0.95
	validation	0.55	7.49	0.64