title: Application of pH-sensitive magnetic nanoparticles microgel as a sorbent for the preconcentration of phenoxy acid herbicides in water samples.
abstract: Introducing new sorbents is an interesting and debatable issue in the field of sample preparation. In this study, for the first time, a pH-sensitive magnetic nanoparticles microgel, Fe3O4-SiO2-oly(4-vinylpyridine), was introduced as a new sorbent. The operating mechanism of this sorbent is based on changing the pH value of the sample and consequently the structure of this pH-sensitive microgel is changed. So that, at pH 6.0 the microgel was ready to accept and load the analytes (partial swelling), and when the pH was increased to 8.0, the microgel was closed and analytes were trapped inside the sorbent (deswelling). At pH 2.0 the microgel was opened and the analytes were released from the microgel (swelling). As the adsorption and desorption mechanism is based on changing the pH and only aqueous medium is used as the effluent solvent, this method is introduced as a green extraction method. The use of this microgel resulted in excellent figures of merit. The limits of quantitation and detection for herbicides were obtained within the range of 10-30 and 3-10 ng mL(-1), respectively. Finally, the proposed method was successfully applied to determine the concentration of phenoxy acid herbicides as hazardous materials in water samples.
authors.affiliation: Department of Environmental Geology, Research Institute of Applied Sciences (ACECR) Shahid Beheshti University, Tehran, Iran. Electronic address: hadi_tabani@yahoo.com.
authors.forename: Hadi
authors.initials: H
authors.lastname: Tabani
authors.affiliation: Department of Environmental Geology, Research Institute of Applied Sciences (ACECR) Shahid Beheshti University, Tehran, Iran.
authors.forename: Kamal
authors.initials: K
authors.lastname: Khodaei
authors.affiliation: Department of applied Chemistry, Faculty of Chemistry, Shahid Beheshti University, G. C., P.O. Box 19396-4716, Evin, Tehran, Iran.
authors.forename: Yasamin
authors.initials: Y
authors.lastname: Bide
authors.affiliation: Department of applied Chemistry, Faculty of Chemistry, Shahid Beheshti University, G. C., P.O. Box 19396-4716, Evin, Tehran, Iran.
authors.forename: Farzaneh Dorabadi
authors.initials: FD
authors.lastname: Zare
authors.affiliation: Department of Environmental Geology, Research Institute of Applied Sciences (ACECR) Shahid Beheshti University, Tehran, Iran.
authors.forename: Saeed
authors.initials: S
authors.lastname: Mirzaei
authors.affiliation: Department of applied Chemistry, Faculty of Chemistry, Shahid Beheshti University, G. C., P.O. Box 19396-4716, Evin, Tehran, Iran.
authors.forename: Ali Reza
authors.initials: AR
authors.lastname: Fakhari
mesh_terms: D000327:Adsorption; D004784:Environmental Monitoring / Q000379:methods*; D005782:Gels / Q000737:chemistry*; D006540:Herbicides / Q000032:analysis*; D008280:Magnetics; D058185:Magnetite Nanoparticles / Q000737:chemistry*; D011725:Pyridines; D012822:Silicon Dioxide / Q000737:chemistry; D014867:Water / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis
chemical_list: D005782:Gels; D006540:Herbicides; D058185:Magnetite Nanoparticles; D011725:Pyridines; D014874:Water Pollutants, Chemical; D014867:Water; D012822:Silicon Dioxide; C029351:4-vinylpyridine
keywords: Capillary electrophoresis; Magnetic nanoparticles; Phenoxy acid herbicides; Water samples; pH-sensitive microgel