Analysis of organic pollutants in sewage by supercritical fluid extraction

Abstract

Analytical methods have been developed for the determination of organic pollutants of intermediate polarity in sewage. Water samples are first passed through a solid phase adsorption cartridge. The analytes are then extracted from the absorbent with supercritical CO2 into a small volume of trapping solvent. Finally, the extracts are analyzed directly by capillary gas chromatography and gas chromatography-mass spectrometer. The various parameters (pressure, temperature, type and concentration of modifiers, trapping solvent, flow rate and volume of supercritical fluid and equilibrium time) influencing the efficiency of extraction were studied. Extraction efficiencies for the test compounds are > 70 %, and relative standard deviations are < 4.6 % (n = 3). The methods established were applied to the analysis of sewage at the Lanzhou Wastewater Treatment Plant, China. 66 organic pollutants were detected, of which 15 compounds appeared in the list of priority pollutants suggested by the US EPA.

Solventless Sample Preparation Techniques in Environmental Analysis

“…Nowadays, due to their superior qualities compared to other extraction media, supercritical fluids have become popular extraction media for different types of analytes from matrices like human and animal tissues [61], sediments [62], fly ash [63], sewage [64], sorbent trap [65], and others [66 -69].…”

Analysis of atmospheric semi-volatile organic pollutants by adsorptiveenrichment and off-line supercritical fluid extraction—Gas chromatography

“…The experimental set-up and operative principle were reported previously [24,25]. The KC-6A air sampler has three main components, namely, a cartridge containing some adsorbent, a pump and a flowmeter.…”

“…Figure 3 is the GC chromatogram of the atmospheric pollutants in the PanxuanRoad (urban street) on a sunny day and a rainy day, respectively. We have determined it in sewage at the Lanzhou Wastewater Treatment Plant, China [25]. Several kinds of gaseous, semivolatile organic contaminants, such as alkanes, PAHs, phthalates, phenols and ketones were detected.…”

Analysis of Unknown Organic Pollutants in Sewage by Solid-Phase Extraction Combined with Gas Chromatography-Mass Spectrometry

“…A large amount of literature reports the deter-mination of target organic compounds in various environmental matrices using GC or GC-MS (1)(2)(3)(4)(5)(6)(7)(8). However, only a few papers have been devoted to the complete identification of a wider-range polarity of unknown organic contaminations in environmental aqueous matrices (9,10). GC-MS is a powerful technique to separate and identify organic pollutants in environmental samples because of its high sensitivity, selectivity, and separation properties (11)(12)(13)(14).…”