title: Microextraction by packed sorbent liquid chromatography with time-of-flight mass spectrometry of triazines employing a molecularly imprinted polymer.
abstract: Molecularly imprinted polymers for the determination of triazines were synthesized by precipitation using atrazine as template, methacrylic acid as functional monomer, ethylene glycol dimethacrylate as crosslinker, and 2,2'-azobisisobutrynitrile as initiator. The polymers were characterized by infrared spectroscopy and scanning electron microscopy and packed in a device for microextraction by packed sorbent aiming for the preconcentration/cleanup of herbicides, such as atrazine, simazine, simetryn, ametryn, and terbutryn in corn samples. Liquid chromatography coupled with time-of-flight mass spectrometry was used for the separation and determination of the herbicides. The selectivity coefficient of molecularly imprinted polymers was compared with that of nonimprinted polymer for the binary mixtures of atrazine/propanil and atrazine/picloram, and the values obtained were 15.6 and 2.96, respectively. The analytical curve ranged from 10 to 80 μg/kg (r = 0.989) and the limits of detection and quantification in the corn matrices were 3.3 and 10 μg/kg, respectively. Intra- and interday precisions were < 14.8% and accuracy was better than 90.9% for all herbicides. Polymer synthesis was successfully applied to the cleanup and preconcentration of triazines from fortified corn samples with 91.1-109.1% of recovery.
authors.affiliation: Institute of Chemistry of Sao Carlos, University of Sao Paulo, Sao Carlos, SP, Brazil.
authors.forename: Felipe Nascimento
authors.initials: FN
authors.lastname: Andrade
authors.forename: Álvaro José
authors.initials: ÁJ
authors.lastname: Santos-Neto
authors.forename: Fernando Mauro
authors.initials: FM
authors.lastname: Lanças
mesh_terms: D000327:Adsorption; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D006540:Herbicides / Q000737:chemistry / Q000302:isolation & purification*; D013058:Mass Spectrometry / Q000379:methods*; D054802:Molecular Imprinting; D011108:Polymers / Q000138:chemical synthesis / Q000737:chemistry*; D052617:Solid Phase Microextraction / Q000295:instrumentation / Q000379:methods*; D014227:Triazines / Q000737:chemistry / Q000302:isolation & purification*
chemical_list: D006540:Herbicides; D011108:Polymers; D014227:Triazines
keywords: Corn; Liquid chromatography with mass spectrometry; Microextraction by packed sorbent; Molecularly imprinted polymers; Triazines