Optimization and Comparison of Microwave‐Assisted Extraction, Supercritical Fluid Extraction, and Eucalyptus Oil–Assisted Extraction of Polycyclic Aromatic Hydrocarbons from Soil and Sediment

Abstract

Polycyclic aromatic hydrocarbons (PAHs) are persistent organic compounds of major concern that mainly accumulate in soils and sediments, and their extraction from environmental matrices remains a crucial step when determining the extent of contamination in soils and sediments. The objective of the present study was to compare the extraction of PAHs (phenanthrene, pyrene, chrysene, and benzo[a]pyrene) from spiked soil and sediment using supercritical fluid extraction (SFE) with ethanol as the modifier, microwave‐assisted extraction (MAE), and eucalyptus oil–assisted extraction (EuAE). Recoveries of PAHs were comparable between the three methods, and >80% of applied pyrene, chrysene and benzo[a]pyrene were recovered. The most efficient method of extracting PAHs from naturally incurred soils with different levels of contamination was SFE. A longer extraction time was required for the EuAE method compared with SFE and MAE under optimized conditions. However, EuAE required lower extraction temperatures (15–20 °C) compared with SFE (80 °C) and MAE (110–120 °C), and consumed less solvent than SFE and MAE. Compared with hexane/acetone used in MAE, the use of ethanol in SFE and eucalyptus oil in EuAE can be considered as more sustainable approaches to efficiently extract PAHs from spiked/naturally contaminated soils and sediments. And, although less efficient for matrices containing higher carbon content, EuAE offered a cheap, low‐tech approach to extracting PAHs. Environ Toxicol Chem 2023;42:982–994. © 2023 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

A Review: Subcritical Water Extraction of Organic Pollutants from Environmental Matrices

“…PAHs are highly soluble in nonpolar solvents and edible oils but have limited solubility in water [ 41 ]. Regardless of the hydrophobic properties of PAHs, a broad range of extraction techniques, such as dispersive solid-phase extraction (d-SPE) [ 42 ], magnetic solid-phase extraction (MSPE) [ 43 ], stir bar sorptive extraction (SBSE) [ 44 ], fabric phase sorptive extraction (FPSE) [ 45 ], SBWE [ 46 ], and SFE [ 47 ], have been developed. The application of SFE for the extraction of PAHs from the environment has become more apparent; however, supercritical water requires extremely high temperatures and pressures (T > 374 °C and P > 221 bar), and it is extremely corrosive [ 48 , 49 ].…”

Phenanthrene Derived Nanoporous Hypercrosslinked Polymeric Adsorbent for CO2 Capture from Flue Gas and Removal of Organic Dyes from Wastewater

“…They are extremely mutagenic, carcinogenic, and quickly absorbed via the skin, causing kidney failure and lifelong blindness. Very importantly, several organic dyes containing chromophores (−NH 2 , NR 2, and −OH) and auxochromes (CO, NN, CC) react with polycyclic aromatic hydrocarbons (PAHs) present in wastewater to form complex carcinogenic secondary pollutants. − PAHs are organic aromatic compounds consisting of only carbon and hydrogen with more than one aromatic ring arranged in a linear or angular fashion. − These aromatics are released into the air, water, and soil by incomplete combustion of tobacco, fossil fuels, wood, and petroleum products. − PAHs with an angular arrangement, like phenanthrene, are found to be more stable and dangerous than linear arrangements. Further, phenanthrene is among the 16 primary hazardous PAHs according to USEPA. − Many PAHs are recognized as carcinogens, mutagens, and teratogens and, thus, pose a serious risk to human health.…”

“…The most prominent and well-known method is solvent extraction including Soxhlet, ultrasonic, liquid−liquid, and solid-phase extractions. 26 However, these techniques can be time consuming and require large volumes of industrial organic solvents. In addition, many of these involve multistep processes, which increase the possibility of some analyte loss.…”

“…The extraction and separation of PAHs from fuels, soils, sediments, air, marine life, and plants has been documented in a number of studies. The most prominent and well-known method is solvent extraction including Soxhlet, ultrasonic, liquid–liquid, and solid-phase extractions . However, these techniques can be time consuming and require large volumes of industrial organic solvents.…”

“…In addition, many of these involve multistep processes, which increase the possibility of some analyte loss. Recently, microwave-assisted extraction, supercritical fluid extraction, and plant oil-assisted extraction are widely used owing to several advantages over conventional solvent extraction, viz., potential reduction in extraction time, solvent consumption, and waste generation, which reduces risks to human operators as well . Additionally, membrane filtration and adsorption process are also widely used to remove PAHs without degrading them into any secondary pollutant. , The pollutants adhere to the surface of the material through physical, chemical, or electrostatic attraction during the process.…”