Table 3.

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 drinking 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	0.086 ± 0.031	108	8.28	0.094 ± 0.001	118	0.35
	0.400	0.415 ± 0.034	104	4.82	0.434 ± 0.003	109	0.63
	0.800	0.834 ± 0.064	104	5.70	0.825 ± 0.008	103	0.99
Co(II)	-	N.D.			N.D.
	0.020	0.020 ± 0.013	100	2.65	0.021 ± 0.001	105	1.36
	0.040	0.041 ± 0.016	103	3.19	0.042 ± 0.002	105	3.07
	0.060	0.063 ± 0.004	105	0.80	0.076 ± 0.001	127	1.81
Ni(II)	-	N.D.			N.D.
	0.800	0.835 ± 0.077	104	4.34	0.786 ± 0.001	98	0.05
	2.000	2.145 ± 0.083	107	2.70	2.168 ± 0.003	108	0.14
	4.000	4.179 ± 0.186	104	3.63	4.092 ± 0.009	102	0.21
Hg(II)	-	N.D.			N.D.
	0.008	0.008 ± 0.003	100	2.91	0.008 ± 0.001	100	1.57
	0.020	0.022 ± 0.003	110	2.49	0.020 ± 0.001	100	0.59
	0.040	0.044 ± 0.001	110	0.58	0.040 ± 0.001	100	0.19
Mn(II)	-	N.D.			N.D.
	0.0040	0.0047 ± 0.0005	118	0.68	0.0049 ± 0.0003	123	2.90
	0.0060	0.0072 ± 0.0013	120	1.78	0.0071 ± 0.0001	118	2.29
	0.0080	0.0096 ± 0.0010	120	1.27	0.0087 ± 0.0001	109	0.69

N.D. none detectable.