Selective and sensitive determination of Cd(II) ions in various samples using a novel modified carbon paste electrode

Journal of Analytical Science and Technology

Table 4 Evaluation of intra- and inter-day precision and accuracy of the Cd(II)-CPE sensor

Samples	[Cd(II)] taken (mg mL⁻¹)	Intra-day				Inter-day
Samples	[Cd(II)] taken (mg mL⁻¹)	[Cd(II)] found (mg mL⁻¹)	Recovery (%)	SD	RSD^* (%)	[Cd(II)] found (mg mL⁻¹)	Recovery (%)	SD	RSD^** (%)
Pure solution	0.25	0.247	98.8	0.003	1.26	0.247	98.8	0.005	2.02
Pure solution	0.30	0.296	98.6	0.007	2.36	0.296	98.6	0.002	0.67
River water	0.25	0.249	99.6	0.007	2.81	0.247	98.8	0.003	1.21
River water	0.30	0.294	98.0	0.005	1.70	0.299	99.6	0.004	1.34
Industrial wastewater	0.25	0.243	97.2	0.006	2.47	0.245	98.0	0.006	2.45
Industrial wastewater	0.30	0.293	97.6	0.008	2.73	0.296	98.6	0.008	2.70
Rechargeable battery waste	0.25	0.248	99.2	0.006	2.42	0.247	98.8	0.006	2.43
Rechargeable battery waste	0.30	0.291	97.0	0.005	1.70	0.294	98.0	0.001	0.34
Plant foodstuff (carrot)	0.25	0.243	97.2	0.003	1.23	0.245	98.0	0.009	3.67
Plant foodstuff (carrot)	0.30	0.292	97.3	0.004	1.37	0.293	97.6	0.006	2.05
Fish tissue	0.25	0.245	98.0	0.004	1.63	0.248	99.2	0.003	1.21
Fish tissue	0.30	0.293	97.6	0.005	1.70	0.298	99.3	0.006	2.01