Solid phase extraction of polyhalogenated pollutants from freshwater using chemically modified multi‐walled carbon nanotubes and their determination by gas chromatography

Abstract

This paper describes the application of pristine and chemically modified multi-walled carbon nanotubes (MWCNTs) as packing materials for the preconcentration and determination of various polyhalogenated organic pollutants, pentachlorophenol, 2,4,5-trichlorophenol, 3,3',4,4'-tetrachlorobiphenyl, and 2,2',5,5'-tetrabromobiphenyl from real water samples based on solid-phase extraction. MWCNTs were chemically modified by octadecyl amine and polyethylene glycol, separately, and the resulting nano materials were used as packing materials for solid phase extraction. Method development, applicability, and suitability of the above mentioned adsorbents for the solid phase extraction were studied. Method development showed great reproducibility and sensitivity, and low limits of detection within a considerable linear range. The regeneration and reusability of the SPE cartridges were studied using Rideau River (Ottawa, Canada) surface water samples and the results showed that cartridges could be used for three cycles of adsorption/desorption with no loss of efficiency. In general, the results suggested that modification of MWCNTs affords a novel class of adsorbents, which could be used for the SPE of various analytes from aqueous solutions with great efficiency, recovery, reproducibility, sensitivity, and precision, within a wide range of analyte concentrations.

Different Aspects of Single Wall Carbon Nanotube Functionalization by Aniline Adsorption; Quantum Mechanics/Molecular Mechanics Study

“…Nowadays it has been proved that adsorption technology is one of the most effective methods for the isolation and removal of high levels of organic pollutants from wastewater. Carbon nanotube is a proper adsorbent that has a high capacity to absorb various pollutants [11][12][13][14][15]. This capability, due to delocalized electrons in the hexagonal arrangement of carbon atoms in the nanotube surface, which leads to a strong interaction between the nanotubes and contaminants.…”

Determination of trace anions in liquefied petroleum gas using liquid absorption and electrokinetic migration for enrichment followed by ion chromatography

“…Enrichment methods make full use of characteristics of analyte, such as mobility, charge, affinity, and size. Generally, anions can be enriched by SPE, which has extensive application in the sample pretreatment [], through using weak anions exchange resins as adsorbent rather than strong anions exchange resins owing to the difficult elution. In order to efficiently enrich the anions, SPE with weak anions exchange resins as the adsorbent should be acidized before the loading sample step, while strong acids (HCl, H 2 SO 4 , etc.)…”