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 4

Comparison of this method with other literature.

Pretreatment method	Amount of extract required for 1 g sample	Purification dosage required for 1 mL extract	Concentration method	Amount of organic reagent in the concentration process	Instrument	Pretreatment time (min)	Recovery (%)	LOD (μg/kg)	Literature
QuEChERS	2 mL ACN; 1.2 g MgSO4, 0.3 g NaCl,; 0.15 g Na2HCit·1.5H2O; 0.3 g Na3Cit·2H2O	QuEChERS:33 mg PSA,; 100 mg MgSO4; 33 mg C18; 33 mg GCB	Nitrogen stream	1 mL Hexane	GC-ECD	16–17	66–111	α-HCH: 0.93; HCB: 3.33; β-HCH: 1.71; Lindane: 0.94; δ-HCH: 1.42; Aldrin: 2.09; α-Endosulfan: 1.77; p,p′-DDE: 2.26; Dieldrin: 2.26; Endrin: 2.08; β-Endosulfan: 2.93; p,p′-DDD: 3.38; o,p′-DDT: 3.16; Methoxychlor: 1.41	[32]
QuEChERS-DLLME	2 mL ACN; 0.8 g MgSO4; 0.2 g NaCl	QuEChERS: 50 mg PSA	DLLME	40 μL undecanol	GC-ECD	19–20	77.2–112.5	α-BHC: 1.02; β-BHC: 1.13; γ-BHC: 0.93; δ-BHC: 0.75; Heptachlor: 1.04; Aldrin: 1.28; Heptachlor Epoxide: 0.45; α-Chlordane: 1.33; Endrin: 0.64; β-Endosulfan: 1.17; p,p′-DDD: 1.32; Endrin aldehyde: 0.96; Endrin ketone: 1.25	[33]
Fe3O4 MNPs-QuEChERS-DLLME	2 mL ACN0.4 g NaCl	QuEChERS: 10 mg carbon black; 10 mg Fe3O4 MNPs	DLLME	40 μL chloroform	GC-MS	12–13	78.6–107.7	α-HCH: 0.22; β-HCH: 0.21; γ-HCH: 0.23; δ-HCH: 0.31; p,p′-DDE: 0.15; p,p′-DDD: 0.24; o,p′-DDT: 0.22; p,p′-DDT: 0.32	This study