Table 4.

Summary of the recovery test of the proposed sensor and the standard method (ICP-OES) for Cu(II), Co(II), Ni(II), Hg(II), and Mn(II) determination in tap water.

Metal ion	Added (mM)	Proposed sensor (n=5)			ICP-OES (n=3)
		Found (mM)	%Recovery	%RSD	Found (mM)	%Recovery	%RSD
Cu(II)	-	N.D.			N.D.
	0.080	0.073 ± 0.021	91	5.69	0.093 ± 0.002	116	0.83
	0.400	0.410 ± 0.037	103	5.24	0.427 ± 0.002	107	1.45
	0.800	0.756 ± 0.021	95	1.98	0.805 ± 0.009	101	0.60
Co(II)	-	N.D.			N.D.
	0.020	0.024 ± 0.004	120	0.83	0.021 ± 0.001	105	4.16
	0.040	0.047 ± 0.011	118	2.25	0.040 ± 0.001	100	5.61
	0.060	0.067 ± 0.018	112	3.48	0.058 ± 0.001	97	2.82
Ni(II)	-	N.D.			N.D.
	0.800	0.856 ± 0.057	107	3.19	0.778 ± 0.002	97	0.10
	2.000	2.135 ± 0.082	107	2.68	2.145 ± 0.006	107	0.29
	4.000	4.056 ± 0.129	101	2.58	4.033 ± 0.016	101	0.29
Hg(II)	-	N.D.			N.D.
	0.008	0.009 ± 0.001	113	1.86	0.008 ± 0.001	100	0.08
	0.020	0.022 ± 0.003	110	1.19	0.019 ± 0.001	95	0.30
	0.040	0.044 ± 0.003	110	2.25	0.040 ± 0.002	100	0.22
Mn(II)	-	0.0047 ± 0.0026			0.0014 ± 0.0002
	0.0040	0.0092 ± 0.0012	113	1.61	0.0061 ± 0.0001	117	1.13
	0.0060	0.0114 ± 0.0023	112	2.92	0.0078 ± 0.0001	107	1.30
	0.0080	0.0139 ± 0.0013	115	1.55	0.0098 ± 0.0002	105	1.04