Trace determination of heptachlor in soil samples by Toner@CuFe2O4 nanocomposites based microextraction-gas chromatography-mass spectrometry

In this paper, a green, sensitive, and accurate analytical method was described for the determination of heptachlor at low levels in the GC-MS system. In this context, the preconcentration of heptachlor was achieved by applying the dispersive solid-phase microextraction (DSPME) method prior to the separation and quantification in the GC-MS system. Toner@CuFe₂O₄ nanocomposites were synthesized by the hydrothermal synthesis method and used as the sorbent for the first time in literature. Under the optimal conditions determined by the univariate optimization approach, the limit of detection (LOD) and limit of quantification (LOQ) were found to be 0.61 µg kg⁻¹ and 2,0 µg kg⁻¹, respectively, and the sensitivity of the GC-MS system was enhanced by 68.5-fold. The applicability of the Toner@CuFe₂O₄-DSPME-GC-MS system was assessed by spiking tests applied to soil samples. The recovery results in the range of 93.2% and 105.7% obtained by applying the matrix matching calibration strategy proved the feasibility of the method. The Eco-scale and BAGI tools developed for green and analytical applicability assessment gave scores of 85 and 65, respectively, confirming that the method is environmentally friendly and analytically applicable.