title: Determination of ten sulfonyl urea herbicides in unpolished rice by solid-phase extraction cleanup and LC-diode array detection.
abstract: A liquid chromatographic (LC) method with diode array detection (DAD) was developed for screening of 10 sulfonyl urea herbicide residues in unpolished rice. The investigated herbicides were azimsulfuron, bensulfuron-methyl, chlorimuron-ethyl, chlorsulfuron, ethoxysulfuron, flazasulfuron, imazosulfuron, metsulfuron-methyl, pyrazosulfuron-ethyl and tribenuron-methyl. Acetonitrile-water (2:1) extracts of rice samples were cleaned up with solid-phase extraction cartridges (octadecylsilane-bonded silica (ODS) and graphitized carbon black (GCB)). Three fractions of the GCB eluate were taken for analysis using 3 separate injections in order to avoid interference in LC-DAD analysis and to reduce analyte coelution problems. Recoveries from rice samples fortified with the 10 herbicides at 0.05 and 0.2 microgram/g ranged from 46.6 to 119.6%, and coefficients of variation were 3.1-12.6%. The quantitation limits were 0.01-0.02 microgram/g.
authors.affiliation: Hyogo Prefectural Institute of Public Health: 2-1-29, Arata-cho, Hyogo-ku, Kobe 652-0032, Japan.
authors.forename: Yumi
authors.initials: Y
authors.lastname: Akiyama
authors.forename: Naoki
authors.initials: N
authors.lastname: Yoshioka
authors.forename: Masahiko
authors.initials: M
authors.lastname: Tsuji
mesh_terms: D002853:Chromatography, Liquid / Q000379:methods*; D006540:Herbicides / Q000032:analysis*; D012275:Oryza / Q000737:chemistry*; D010573:Pesticide Residues / Q000032:analysis*; D013453:Sulfonylurea Compounds / Q000032:analysis*
chemical_list: D006540:Herbicides; D010573:Pesticide Residues; D013453:Sulfonylurea Compounds