title: Molecularly imprinted solid-phase extraction and high-performance liquid chromatography with ultraviolet detection for the determination of urinary trans,trans-muconic acid: a comparison with ionic exchange extraction.
abstract: A new molecularly imprinted polymer (MIP) has been synthesized for the selective extraction of trans,trans-muconic acid (ttMA) from urine samples, followed by high-performance liquid chromatography analysis with ultraviolet detection. The synthesis was based on non-covalent interactions, and 4-vinylpyridine was used as a functional monomer. The analytical calibration curve was prepared using a pool of five urine samples of non-smokers spiked with ttMA standards with concentrations that ranged from 0.3 to 10 mg L(-1) (r(2) = 0.999). The limit of quantification was 0.3 mg L(-1) (lower than the biological exposure limits suggested by the ACGIH). The within-day and between-day precision and accuracy presented relative standard deviations and relative errors of less than 15%. The analytical frequency was 4 h(-1) (considering extraction and separation/quantification steps), and the same MIP cartridge was efficiently used for approximately 100 cycles. All figures of merit were similar or better than those obtained by the procedure based on ionic exchange extraction. The proposed method could be an interesting alternative for the routine analysis of ttMA in urine for biological monitoring procedures of human exposure to benzene.
authors.affiliation: Laboratory of Toxicant and Drug Analysis, Federal University of Alfenas-Unifal-MG, Gabriel Monteiro da Silva St. 700. 37130-000 Alfenas, MG, Brazil.
authors.forename: André Coutinho
authors.initials: AC
authors.lastname: Vieira
authors.forename: Rodolfo Aurélio
authors.initials: RA
authors.lastname: Zampieri
authors.forename: Maria Elisa Pereira Bastos
authors.initials: ME
authors.lastname: de Siqueira
authors.forename: Isarita
authors.initials: I
authors.lastname: Martins
authors.forename: Eduardo Costa
authors.initials: EC
authors.lastname: Figueiredo
mesh_terms: D001554:Benzene / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D002852:Chromatography, Ion Exchange; D004784:Environmental Monitoring; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007536:Isomerism; D054802:Molecular Imprinting; D011108:Polymers / Q000737:chemistry; D011725:Pyridines / Q000737:chemistry; D052616:Solid Phase Extraction; D013011:Sorbic Acid / Q000031:analogs & derivatives* / Q000032:analysis / Q000302:isolation & purification; D013056:Spectrophotometry, Ultraviolet
chemical_list: D011108:Polymers; D011725:Pyridines; C005939:muconic acid; C029351:4-vinylpyridine; D001554:Benzene; D013011:Sorbic Acid