title: Iron oxide functionalized graphene nano-composite for dispersive solid phase extraction of chemical warfare agents from aqueous samples.
abstract: Present study deals with the preparation and evaluation of graphene based magnetic nano-composite for dispersive solid phase extraction of Chemical Weapons Convention (CWC) relevant chemicals from aqueous samples. Nano-composite, Fe3O4@SiO2-G was synthesized by covalently bonding silica coated Fe3O4 onto the graphene sheets. Nerve agents (NA), Sulfur mustard (SM) and their non-toxic environmental markers were the target analytes. Extraction parameters like amount of sorbent, extraction time and desorption conditions were optimized. Dispersion of 20 milligram of sorbent in 200mL of water sample for 20min. followed by methanol/chloroform extraction produced average to good recoveries (27-94%) of targeted analytes. Recoveries of real agents exhibited great dependency upon sample pH and ionic strength. Sarin produced maximum recovery under mild acidic conditions (56% at pH 5) while VX demanded alkaline media (83% at pH 9). Salts presence in the aqueous samples was found to be advantageous, raising the recoveries to as high as 94% for SM. Excellent limits of detection (LOD) for sulphur mustard and VX (0.11ngmL(-1) and 0.19ngmL(-1) respectively) proved the utility of the developed method for the off-site analysis of CWC relevant chemicals.
authors.affiliation: Vertox Laboratory, Defence Research and Development Establishment, Jhansi Road, Gwalior -474002, India.
authors.forename: Sridhar
authors.initials: S
authors.lastname: Chinthakindi
authors.affiliation: Vertox Laboratory, Defence Research and Development Establishment, Jhansi Road, Gwalior -474002, India.
authors.forename: Ajay
authors.initials: A
authors.lastname: Purohit
authors.affiliation: Vertox Laboratory, Defence Research and Development Establishment, Jhansi Road, Gwalior -474002, India.
authors.forename: Varoon
authors.initials: V
authors.lastname: Singh
authors.affiliation: Vertox Laboratory, Defence Research and Development Establishment, Jhansi Road, Gwalior -474002, India.
authors.forename: Vijay
authors.initials: V
authors.lastname: Tak
authors.affiliation: Vertox Laboratory, Defence Research and Development Establishment, Jhansi Road, Gwalior -474002, India.
authors.forename: D Raghavender
authors.initials: DR
authors.lastname: Goud
authors.affiliation: Vertox Laboratory, Defence Research and Development Establishment, Jhansi Road, Gwalior -474002, India.
authors.forename: D K
authors.initials: DK
authors.lastname: Dubey
authors.affiliation: Vertox Laboratory, Defence Research and Development Establishment, Jhansi Road, Gwalior -474002, India. Electronic address: dkpardasani@drde.drdo.in.
authors.forename: Deepak
authors.initials: D
authors.lastname: Pardasani
mesh_terms: D002619:Chemical Warfare Agents / Q000302:isolation & purification*; D005290:Ferric Compounds; D006108:Graphite; D006863:Hydrogen-Ion Concentration; D057230:Limit of Detection; D009151:Mustard Gas / Q000302:isolation & purification; D053761:Nanocomposites; D009943:Organophosphorus Compounds / Q000302:isolation & purification; D009994:Osmolar Concentration; D012822:Silicon Dioxide; D052616:Solid Phase Extraction / Q000379:methods*; D014867:Water / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*
chemical_list: D002619:Chemical Warfare Agents; D005290:Ferric Compounds; D009943:Organophosphorus Compounds; D014874:Water Pollutants, Chemical; D014867:Water; C000499:ferric oxide; D012822:Silicon Dioxide; D006108:Graphite; D009151:Mustard Gas
keywords: Chemical warfare agents; Graphene; Magnetic dispersive solid phase extraction; Magnetic nano particles; Nerve agents; Sulfur mustard