Table 5.

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 pond 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	0.081 ± 0.023	101	6.30	0.090 ± 0.001	113	0.46
	0.400	0.434 ± 0.035	109	4.87	0.417 ± 0.004	104	0.87
	0.800	0.748 ± 0.024	94	2.36	0.792 ± 0.006	99	0.81
Co(II)	-	N.D.			N.D.
	0.020	0.022 ± 0.015	110	3.03	0.022 ± 0.001	110	4.16
	0.040	0.044 ± 0.012	110	2.31	0.039 ± 0.001	98	5.61
	0.060	0.066 ± 0.013	110	2.46	0.058 ± 0.001	97	2.82
Ni(II)	-	N.D.			N.D.
	0.800	0.839 ± 0.098	105	5.49	0.786 ± 0.001	98	0.01
	2.000	2.128 ± 0.121	106	3.94	2.154 ± 0.004	108	0.27
	4.000	4.218 ± 0.157	105	3.05	4.087 ± 0.018	102	0.50
Hg(II)	-	N.D.			N.D.
	0.008	0.008 ± 0.005	100	3.45	0.008 ± 0.001	100	1.68
	0.020	0.022 ± 0.006	110	4.46	0.022 ± 0.001	110	1.79
	0.040	0.044 ± 0.003	110	4.63	0.043 ± 0.001	108	0.91
Mn(II)	-	N.D.			N.D.
	0.0040	0.0050 ± 0.0007	125	1.02	0.0045 ± 0.0001	113	2.15
	0.0060	0.0074 ± 0.0022	123	2.89	0.0067 ± 0.0003	112	2.80
	0.0080	0.0099 ± 0.0017	124	2.22	0.0084 ± 0.0004	105	3.13

CU refers to Chulalongkorn University.