title: Assessing solvent derivatization and carbon dioxide supercritical fluid simultaneous extraction/derivatization of cyprodinil.
abstract: Derivatization of cyprodinil with different reagents and solvents has been evaluated to improve the GC/MS characterization of this fungicide. After assessing some preliminary acylation and silylation reactions, derivatization with anhydrous heptafluorobutyric anhydride (HFBA) was selected as the best derivatization option for cyprodinil. The HFBA-cyprodinil derivative was clearly identified and characterized by GC/MS (ion-trap). The spectrum of the HFBA derivative of cyprodinil was characterized by the base peak, 252 m/z ion, and two other ions with relative abundances of 5% (224 m/z ion) and 4% (420 m/z molecular ion). Conversion rates in the range of 83-92% were obtained when 0.1-1 μg cyprodinil were derivatized in vial without solvent at 25ºC temperature for 120 min, with 5 μL HFBA and 5 μL pyridine. Simultaneous extraction-derivatization of cyprodinil in supercritical carbon dioxide was only achieved when no modifier was present, but conversion/recovery rates obtained in the replicate experiments carried out with 15 mL supercritical carbon dioxide at 50°C and 200 atm (n = 5), 300 atm (n = 7), and 400 atm (n = 5) were no reproducible (RSD > 50%) and ranged between 10% and 45% (related to the signal obtained for derivatization in vial).
authors.affiliation: a Pesticide Residue Research Group , University of Almería , Almería , Spain.
authors.forename: Ana
authors.initials: A
authors.lastname: Aguilera
authors.forename: Antonio
authors.initials: A
authors.lastname: Valverde
authors.forename: Antonio
authors.initials: A
authors.lastname: Valverde-Monterreal
authors.forename: Luis
authors.initials: L
authors.lastname: Garcia-Fuentes
authors.forename: Mourad
authors.initials: M
authors.lastname: Boulaid
mesh_terms: D002245:Carbon Dioxide / Q000737:chemistry; D005466:Fluorocarbons / Q000737:chemistry*; D005659:Fungicides, Industrial / Q000737:chemistry*; D008401:Gas Chromatography-Mass Spectrometry / Q000295:instrumentation; D011743:Pyrimidines / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry*
chemical_list: D005466:Fluorocarbons; D005659:Fungicides, Industrial; D011743:Pyrimidines; D012997:Solvents; D002245:Carbon Dioxide; C007924:heptafluorobutyric anhydride; C108338:cyprodinil
keywords: Derivatization; GC/MS; SFE; cyprodinil