title: Determination of trace levels of triazines in corn matrices by bar adsorptive microextraction with a molecularly imprinted polymer.
abstract: This manuscript addresses the determination of triazines (ametryn, atrazine, simazine, and terbutryn) in corn matrices using bar adsorptive microextraction coated with a selective molecularly imprinted polymer phase following microliquid desorption and high-performance liquid chromatography with diode array detection. The molecularly imprinted polymer was synthesized using atrazine as a template and methacrylic acid as a functional monomer. Assays performed in 25 mL of ultrapure water samples spiked at 8.0 μg/L yielded 80-120 % recoveries under the evaluated experimental conditions. The method showed an accuracy (0.2 < bias < 17.9%), precision (relative standard deviation <17.4%), convenient detection (0.2 μg/L), and quantification (0.7 μg/L) limits, as well as linear dynamic ranges (0.8-24.0 μg/L) with remarkable determination coefficients (R(2) > 0.9926). The proposed analytical method was applied to monitor triazines in three types of corn matrices using the standard addition methodology. Experiments performed in corn samples spiked with triazines at the trace level (8.0 μg/kg of each analyte) gave rise to recoveries (81.0-119.4%) with good reproducibility and robustness. The proposed methodology is also easy to implement and showed to be a good analytical alternative to monitor triazines in complex matrices, when compared with other sorption-based microextraction techniques.
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.affiliation: Centro de Química e Bioquímica, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, Lisboa, Portugal.
authors.forename: Alessandra Honjo
authors.initials: AH
authors.lastname: Ide
authors.affiliation: Centro de Química e Bioquímica, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, Lisboa, Portugal.
authors.forename: Nuno da Rosa
authors.initials: Nda R
authors.lastname: Neng
authors.affiliation: Institute of Chemistry of Sao Carlos, University of Sao Paulo, Sao Carlos, SP, Brazil.
authors.forename: Fernando Mauro
authors.initials: FM
authors.lastname: Lanças
authors.affiliation: Centro de Química e Bioquímica, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, Lisboa, Portugal.
authors.forename: José Manuel Florêncio
authors.initials: JM
authors.lastname: Nogueira
mesh_terms: D000327:Adsorption; D002849:Chromatography, Gas; D002851:Chromatography, High Pressure Liquid; D005742:Gasoline; D005782:Gels / Q000737:chemistry; D006838:Hydrocarbons / Q000737:chemistry; D059627:Liquid Phase Microextraction; D010316:Particle Size; D011108:Polymers / Q000737:chemistry*; D015203:Reproducibility of Results; D012822:Silicon Dioxide / Q000737:chemistry; D052617:Solid Phase Microextraction / Q000379:methods*; D013696:Temperature; D014227:Triazines / Q000737:chemistry*; D003313:Zea mays
chemical_list: D005742:Gasoline; D005782:Gels; D006838:Hydrocarbons; D011108:Polymers; D014227:Triazines; D012822:Silicon Dioxide
keywords: Bar adsorptive microextraction; Corn; Floating sampling technology; Molecularly imprinted polymers; Triazines