Table 6.

LOD values of ICP-OES analysis and preconcentration factors (PF) obtained for selected metal ions with different adsorbents.

Metal	SiO2-PHMG-NRS			SiO2-PHMG-NNS
	LOD, ng mL−1	PF	RSD, %	LOD, ng mL−1	PF	RSD, %
Cu(II)	0.76	40	0.68	0.75	80	0.77
Fe(III)	0.83	40	1.47	0.82	80	1.35
Al(III)	1.34	32	2.17	1.35	66	2.23
Ni(II)	0.95	26	1.64	0.96	28	1.52
Zn(II)	0.77	24	0.89	0.77	30	0.93
Pb(II)	0.87	20	2.35	0.88	42	1.98