Application of dispersive liquid–liquid microextraction coupled with vortex-assisted hydrophobic magnetic nanoparticles based solid-phase extraction for determination of aflatoxin M1 in milk samples by sensitive micelle enhanced spectrofluorimetry
2015
Amoli-Diva, Mitra | Taherimaslak, Zohreh | Allahyari, Mehdi | Pourghazi, Kamyar | Manafi, Mohammad Hanif
An efficient, simple and fast low-density solvent based dispersive liquid–liquid microextraction (LDS-DLLME) followed by vortex-assisted dispersive solid phase extraction (VA-D-SPE) has been developed as a new approach for extraction and preconcentration of aflatoxin M1 in milk samples prior to its micelle enhanced spectrofluorimetic determination. In this LDS-DLLME coupled VA-D-SPE method, milk samples were first treated with methanol/water (80:20, v/v) after removing the fat layer. This solvent was directly used as the dispersing solvent in DLLME along with using 1-heptanol (as a low-density solvent with respect to water) as the extracting solvent. In VA-D-SPE approach, hydrophobic oleic acid modified Fe3O4 nanoparticles were used to retrieve the analyte from the DLLME step. It is considerably that the target of VA-D-SPE was 1-heptanol rather than the aflatoxin M1 directly. The main parameters affecting the efficiency of LDS-DLLME and VA-D-SPE procedures and signal enhancement of aflatoxin M1 were investigated and optimized. Under the optimum conditions, the method was linear in the range from 0.02 to 200µgL⁻¹ with the correlation coefficient (R²) of 0.9989 and detection limit of 13ngL⁻¹. The intra-day precision was 2.9 and 4.3% and the inter-day precision was 2.1 and 3.3% for concentration of 2 and 50µgL⁻¹ respectively. The developed method was applied for extraction and preconcentration of AFM1 in three commercially available milk samples and the results were compared with the official AOAC method.
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