Analysis of chemical warfare agents in organic liquid samples with magnetic dispersive solid phase extraction and gas chromatography mass spectrometry for verification of the chemical weapons convention.
A simple, sensitive and low temperature sample preparation method is developed for detection and identification of Chemical Warfare Agents (CWAs) and scheduled esters in organic liquid using magnetic dispersive solid phase extraction (MDSPE) followed by gas chromatography-mass spectrometry analysis. The method utilizes Iron oxide@Poly(methacrylic acid-co-ethylene glycol dimethacrylate) resin (Fe2O3@Poly(MAA-co-EGDMA)) as sorbent. Variants of these sorbents were prepared by precipitation polymerization of methacrylic acid-co-ethylene glycol dimethacrylate (MAA-co-EGDMA) onto Fe2O3 nanoparticles. Fe2O3@poly(MAA-co-EGDMA) with 20% MAA showed highest recovery of analytes. Extractions were performed with magnetic microspheres by MDSPE. Parameters affecting the extraction efficiency were studied and optimized. Under the optimized conditions, method showed linearity in the range of 0.1-3.0μgmL(-1) (r(2)=0.9966-0.9987). The repeatability and reproducibility (relative standard deviations (RSDs) %) were in the range of 4.5-7.6% and 3.4-6.2% respectively for organophosphorous esters in dodecane. Limits of detection (S/N=3/1) and limit of quantification (S/N=10/1) were found to be in the range of 0.05-0.1μgmL(-1) and 0.1-0.12μgmL(-1) respectively in SIM mode for selected analytes. The method was successfully validated and applied to the extraction and identification of targeted analytes from three different organic liquids i.e. n-hexane, dodecane and silicon oil. Recoveries ranged from 58.7 to 97.3% and 53.8 to 95.5% at 3μgmL(-1) and 1μgmL(-1) spiking concentrations. Detection of diethyl methylphosphonate (DEMP) and O-Ethyl S-2-diisopropylaminoethyl methylphosphonothiolate (VX) in samples provided by the Organization for Prohibition of Chemical Weapons Proficiency Test (OPCW-PT) proved the utility of the developed method for the off-site analysis of CWC relevant chemicals.
Vertox Laboratory, Defence Research and Development Establishment, Jhansi road, Gwalior 474002, India.
Varoon
V
Singh
Vertox Laboratory, Defence Research and Development Establishment, Jhansi road, Gwalior 474002, India.
Ajay Kumar
AK
Purohit
Vertox Laboratory, Defence Research and Development Establishment, Jhansi road, Gwalior 474002, India.
Sridhar
S
Chinthakindi
Vertox Laboratory, Defence Research and Development Establishment, Jhansi road, Gwalior 474002, India.
Raghavender D
RD
Goud
Vertox Laboratory, Defence Research and Development Establishment, Jhansi road, Gwalior 474002, India.
Vijay
V
Tak
Vertox Laboratory, Defence Research and Development Establishment, Jhansi road, Gwalior 474002, India.
Deepak
D
Pardasani
Electron Microscopy Division, Defence Research and Development Establishment, Jhansi road, Gwalior 474002, India.
Anchal Roy
AR
Shrivastava
Vertox Laboratory, Defence Research and Development Establishment, Jhansi road, Gwalior 474002, India. Electronic address: dkdubey@rediffmail.com.
Devendra Kumar
DK
Dubey
D000473:Alkanes / Q000737:chemistry*; D002619:Chemical Warfare Agents / Q000032:analysis*; D005290:Ferric Compounds / Q000737:chemistry; D008401:Gas Chromatography-Mass Spectrometry / Q000295:instrumentation / Q000379:methods; D006586:Hexanes / Q000737:chemistry*; D008280:Magnetics; D063065:Organophosphonates / Q000032:analysis*; D009946:Organothiophosphorus Compounds / Q000032:analysis*; D011109:Polymethacrylic Acids / Q000737:chemistry; D015203:Reproducibility of Results; D012827:Silicone Oils / Q000737:chemistry*; D052616:Solid Phase Extraction / Q000379:methods
D000473:Alkanes; D002619:Chemical Warfare Agents; D005290:Ferric Compounds; D006586:Hexanes; D063065:Organophosphonates; D009946:Organothiophosphorus Compounds; D011109:Polymethacrylic Acids; D012827:Silicone Oils; C497090:poly((ethylene glycol dimethacrylate)-co-(methacrylic acid)); C007548:n-dodecane; C000499:ferric oxide; C026385:n-hexane
Chemical warfare agents; Chemical weapons convention; GC–MS; Magnetic dispersive solid phase extraction; Magnetic nanoparticles; Sample preparation