A Highly Sensitive Electrochemical Sensor Based on Electrocatalytic Reduction Effect of Cu²⁺ on Trace Determination of Malathion in Soil and Other Complex Matrices

Table 3

Determination of malathion in soil, vegetables (ng g⁻¹), and water (ng mL⁻¹) samples by the developed SW-CSV method.

Sample matrix	Malathion (µg L^−1)		Recovery ± RSD (%)
	Added	Found ± SD
Soil	0	0.60 ± 0.05	-
	5	5.05 ± 0.07	101.0 ± 1.39
	10	10.4 ± 0.08	104.0 ± 0.77
	20	20.8 ± 0.07	104.0 ± 0.34
Cabbage	0	0.35 ± 0.06	-
	5	5.10 ± 0.05	102.0 ± 0.98
	10	9.72 ± 0.08	97.20 ± 0.82
	20	19.50 ± 0.10	97.50 ± 0.51
Spinach	0	1.50 ± 0.05	-
	5	4.90 ± 0.04	97.0 ± 0.82
	10	9.70 ± 0.08	98.5 ± 0.82
	20	19.7 ± 0.10	98.0 ± 0.51
Tap water	0	n.d.	-
	5	5.70 ± 0.04	114.0 ± 0.70
	10	10.68 ± 0.08	106.5 ± 0.75
	20	21.50 ± 0.10	107.5 ± 0.47

Average (n = 5) ± standard deviation (SD); n.d. = not detected. In soil, cabbage, and spinach, the found value was calculated as the difference between the measured value at various spiking concentrations minus the value obtained before adding malathion.