Determination of Organochlorine Pesticides in Green Leafy Vegetable Samples via Fe₃O₄ Magnetic Nanoparticles Modified QuEChERS Integrated to Dispersive Liquid-Liquid Microextraction Coupled with Gas Chromatography-Mass Spectrometry

Table 3

Recoveries (n = 5) and RSDs obtained from 8 OCPs spiked in spinach, cabbage, oilseed rape, and lettuce at three levels.

Compounds	Spiked (μg/kg)	Spinach		Cabbage		Oilseed rape		Lettuce
		Recovery (%)	RSD (%)	Recovery (%)	RSD (%)	Recovery (%)	RSD (%)	Recovery (%)	RSD (%)
α-HCH	2	88.7	3.1	98.7	3.5	89.3	1.2	84.4	6.4
	20	101.2	3.2	98.0	5.5	85.1	2.7	88.3	5.4
	40	92.0	4.5	103.2	4.3	78.6	3.8	80.1	4.7
β-HCH	2	106.5	6.6	104.7	7.0	95.5	7.4	98.5	2.9
	20	89.0	4.3	92.3	5.4	91.6	2.7	96.3	5.8
	40	103.1	7.2	89.9	4.9	88.5	5.1	102.0	5.3
γ-HCH	2	92.3	3.8	97.1	2.1	94.7	1.6	101.4	1.8
	20	88.9	4.9	98.4	1.7	104.3	3.7	103.2	1.1
	40	97.2	3.3	101.3	2.8	96.6	4.1	94.7	4.2
δ-HCH	2	99.9	2.4	95.4	2.5	95.6	7.3	85.5	5.1
	20	96.5	3.5	100.2	5.7	90.2	5.7	80.6	3.6
	40	107.7	4.7	105.7	6.0	102.9	4.2	79.0	4.6
p,p′-DDE	2	102.4	4.6	88.6	3.7	106.5	3.6	100.8	1.8
	20	105.3	6.7	87.1	2.2	96.6	2.0	102.6	2.6
	40	97.0	5.9	90.5	4.3	90.8	2.1	91.7	3.7
p,p′-DDD	2	96.0	6.8	91.6	3.7	89.3	5.6	95.6	7.5
	20	92.7	4.5	92.3	2.1	85.4	4.8	95.2	5.4
	40	95.5	7.5	82.0	3.2	98.5	1.7	102.3	4.6
o,p′-DDT	2	87.2	4.5	84.2	2.4	89.9	2.2	94.8	1.6
	20	98.3	3.2	88.9	1.6	96.6	1.5	104.7	3.2
	40	96.8	2.4	90.8	3.1	102.1	3.4	89.3	3.1
p,p′-DDT	2	87.3	1.6	78.7	2.9	95.0	2.5	87.0	2.4
	20	85.5	2.5	80.6	3.5	91.5	1.4	96.3	4.5
	40	95.1	5.3	85.0	4.7	92.3	4.0	92.5	2.5