Resumen

SANTOS-HERNANDEZ, Ana Susana et al. Atrazine and 2, 4-D Determination in Corn Samples Using Microwave Assisted Extraction and On-line Solid-phase Extraction Coupled to Liquid Chromatography. J. Mex. Chem. Soc [online]. 2018, vol.62, n.2, pp.282-294. ISSN 1870-249X.  https://doi.org/10.29356/jmcs.v62i2.475.

In this study, on-line sample pretreatment (clean-up and analyte preconcentration) using sequential injection analysis was coupled to high performance liquid chromatography with UV detection (HPLC/UV) for the determination of 2,4-D (2,4-dichlorophenoxyacetic acid) and atrazine in corn samples. Prior to their analysis, microwave-assisted extraction approach for 2,4-D and atrazine in corn samples was carried out using MeOH: H2O (30:70 v/v) solvent at 50°C for 20 min. The on-line SPE-HPLC/UV approach combined reversed solid-phase extraction using Strata X sorbent with MeOH: H2O (80:20 v/v) at 1 mL min-1 as eluent for the enrichment of the analytes. C18 monolithic column with ACN: 10 mM CH3COOH/CH3COONa buffer at pH 4 (20:80, v/v) was employed as mobile phase at 2 mL min-1 flow rate for chromatographic separation of the compounds before UV detection. Enrichment factors up to 13.4 were achieved with a 10 mL sample volume. The developed procedure showed linear response ranges from 0.07-0.70 mg kg−1 for 2,4-D and atrazine with correlation coefficients >0.993. The LODs were 0.03 and 0.02 mg kg-1 for 2,4-D and atrazine, respectively with RSD ranged from 4.0 to 7.2 % at concentration level of 0.07 and 0.30 mg kg-1. The extraction recoveries of 2,4-D and atrazine in corn samples were from 82.6 to 98.2%. The proposed method showed good recoveries and reasonable precision for herbicide analysis in corn samples avoiding the time-consuming batch sample pretreatment step, and thus minimizing risks of sample contamination and analyte losses.

Palabras llave : herbicide; corn; microwave assisted extraction; on-line SPE-HPLC/UV.

        · resumen en Español     · texto en Inglés     · Inglés ( pdf )