title: Deep eutectic solvent magnetic bucky gels in developing dispersive solid phase extraction: Application for ultra trace analysis of organochlorine pesticides by GC-micro ECD using a large-volume injection technique.
abstract: Novel deep eutectic solvent (DES) magnetic bucky gels (MBG) were formed by choline chloride/urea deep eutectic solvent and magnetic multi-walled carbon nanotube nanocomposite (MMWCNT) and were used in developing dispersive solid-phase extraction (dSPE) method. The hydrophilic DES based MBGs were developed with the features of magnetic susceptibility to permit fast injection of sorbent into the aqueous sample, rapid retrieval of the sorbent, high dispersion of MWCNT in water and compatibility with GC. In this work we investigated the application of DESs as a new class of carriers for CNT based nanofluids. In this gel DES acts simultaneously as a carrier and stabilizer for MMWCNT nanoparticles. By combining the MWCNT nanocomposite and DES, a highly stable (stability against sedimentation) viscous magnetic bucky gel or soft material was prepared without any additional stabilizer. This gel possesses fluidity, stability, magnetic properties and the unique strong sorbing properties of MWCNT simultaneously. We used the advantages of this magnetic DES based soft material in developing a new DES magnetic bucky gel based dispersive solid phase extraction. By coupling this method with GC- micro ECD and using large-volume-injection technique we achieved low LOD values which is a necessity in the ultra trace analysis of organochlorine pesticides (OCPs) in environmental water samples. Under the optimized conditions, the enrichment factors were in the range of 270-340. The limits of detection were between 0.04 and 0.27ng/L and the relative standard deviations were <10%. This method was successfully used for the determination of OCPs with good reproducibility and recovery.
authors.affiliation: Department of Analytical Chemistry, Faculty of Chemistry, University College of Science, University of Tehran, P.O. Box 14155-6455, Tehran, Iran.
authors.forename: Seyedeh Mahboobeh
authors.initials: SM
authors.lastname: Yousefi
authors.affiliation: Department of Analytical Chemistry, Faculty of Chemistry, University College of Science, University of Tehran, P.O. Box 14155-6455, Tehran, Iran. Electronic address: shemiran@khayam.ut.ac.ir.
authors.forename: Farzaneh
authors.initials: F
authors.lastname: Shemirani
authors.affiliation: Faculty of Chemical Engineering, School of Engineering, University of Tehran, Tehran, Iran.
authors.forename: Sohrab Ali
authors.initials: SA
authors.lastname: Ghorbanian
mesh_terms: D002849:Chromatography, Gas / Q000379:methods*; D005782:Gels; D006843:Hydrocarbons, Chlorinated / Q000032:analysis* / Q000737:chemistry / Q000302:isolation & purification; D057230:Limit of Detection; D008280:Magnetics; D010575:Pesticides / Q000032:analysis* / Q000737:chemistry / Q000302:isolation & purification; D052616:Solid Phase Extraction / Q000379:methods*; D012997:Solvents / Q000737:chemistry*
chemical_list: D005782:Gels; D006843:Hydrocarbons, Chlorinated; D010575:Pesticides; D012997:Solvents
keywords: Deep eutectic solvent; Dispersive solid phase extraction; Large volume injection; Magnetic bucky gel; Organochlorine pesticides (OCPs)