Development of a dispersive liquid-liquid microextraction technique for the analysis of aryloxyphenoxy-propionate herbicides in soy-based foods

E. LUBOMIRSKY; JUAN M. PADRÓ; M. RETA

MICROCHEMICAL JOURNAL

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2016 vol. 129 p. 63 - 70

0026-265X

In this work, an ionic liquid?dispersive liquid-liquid microextraction (IL-DLLME) method combined with liquidchromatography and diode-array detection (DAD) was used for the determination of four aryloxyphenoxypropionateherbicides (fenoxaprop-p-ethyl, quizalofop-p-tefuryl, propaquizafop and haloxyfop-p-methyl) intwo soy-based foods (soy milk and soy sauce) was used. For this purpose, the phosphonium-based roomtemperatureionic liquid (trihexyl(tetradecyl)phosphonium bistriflamide) was used as the extractant. The effect of theexperimental parameters on extraction efficiency such as type of disperser solvent, disperser solvent/ ionic liquidvolumes ratio, pH, nature and concentration of salt in the aqueous phase, sample volume, and centrifugation andextraction times were investigated and optimized. Since matrix effects were detected, the standard additionmethod was used for quantification. Under the optimized conditions, the proposed sample preparation methodcoupled to high performance liquid chromatography-diode array detection (HPLC-DAD) had a satisfactoryperformance to determine the four herbicides in soy sauce and soy milk. The enrichment factors ranged from18 to 43 and recovery factors from 25 to 66%. Although the recoveries were not high because of the presenceof organic solvent in the sample preparation step, the inter-day reproducibility was 8.4% or less, depending onthe analyte, the limits of detection (S/N = 3) were obtained in the range of 0.12?0.34 mg L, the limits ofquantification (S/N = 10) between 0.36 and 1.04 mg L−1, and linear ranges from LOQs to 9.26 mg L.Finally,the IL-DLLME methodology is inexpensive, simple, fast, and environmentally friendly for the determination ofthe studied herbicides in soy sauce and soy milk. This study constitutes the first application of an IL-DLLMEmethodology to aryloxyphenoxy-propionate herbicides analysis in commercial soy-derived foods.−1−1