Liquid-liquid-solid microextraction and detection of nerve agent simulants by on-membrane Fourier transform infrared spectroscopy.

Autor: Garg P; Vertox Laboratory, Defence Research & Development Establishment, Gwalior 474002, India., Purohit A, Tak VK, Kumar A, Dubey DK
Jazyk: angličtina
Zdroj: Analytica chimica acta [Anal Chim Acta] 2012 Nov 02; Vol. 751, pp. 71-8. Date of Electronic Publication: 2012 Sep 18.
DOI: 10.1016/j.aca.2012.09.013
Abstrakt: A coupling of novel liquid-liquid-solid microextraction (LLSME) technique based on porous hydrophobic membrane and Fourier-transform infrared spectroscopy has been presented for the detection, identification and quantification of markers and simulants of nerve agents. Two isomers O,O'-dihexyl methylphosphonate (DHMP) and O,O'-dipentyl isopropylphosphonate (DPIPP) were chosen as model analytes for the study. In the present technique, organic phase was immobilised within the pores of membrane after fixing it in an assembly, which was then immersed into aqueous sample of target analytes for extraction. The analytes were directly determined on the surface of membrane by FTIR spectroscopy without elution. On comparison with solid phase microextraction (SPME), LLSME was found to be much more efficient. The method was optimised and quantitative analyses were performed using calibration curves obtained via Beer's law and employing processing of spectra obtained, via a multivariate calibration technique partial least square (PLS). Relative standard deviations (RSDs) for intraday repeatability and interday reproducibility were found to be in the range of 0.20-0.50% and 0.20-0.60%, respectively. Limit of detection (LOD) was achieved up to 15 ng mL(-1). Applicability of the method was tested with an unknown real sample obtained in an international official proficiency test (OPT).
(Copyright © 2012 Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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