Polycyclic aromatic hydrocarbons ultrasonic extraction

Hubert et al. [101] state that accelerated solvent extraction compared to alternatives such as Soxhlet extraction, steam distillation, microwave extraction, ultrasonic extraction and, in some cases, supercritical fluid extraction is an exceptionally effective extraction technique. Hubert et al. [ 101 ] studied the effect of operating variables such as choice of solvent and temperature on the solvent extraction of a range of accelerated persistent organic pollutants in soil, including chlorobenzenes, HCH isomers, DDX, polychlorobiphenyl cogeners and polycyclic aromatic hydrocarbons. Temperatures ofbetween 20 and 180 °C were studied. The optimum extraction conditions use two extraction steps at 80 and 140 °C with static cycles (extraction time 35 minutes) using toluene as a solvent and at a pressure of 15 MPa. 

However, Popp et al. [148] desorbed extracted polycyclic aromatic hydrocarbons by ultrasonic treatment of the stir bar in acetonitrile or acetonitrile water mixtures in order to perform liquid chromatographic analyses of the extract. 

Miguel AH, De Andrade JB. 1989. Rapid quantitation of ten polycyclic aromatic hydrocarbons in atmospheric aerosols by direct HPLC separation after ultrasonic acetonitrile extraction. Int J Environ Anal Chem 35(1) 35-41. 

Sun, F., Littlejohn, D., and Gibson, M. D., Ultrasonication extraction and solid phase extraction clean-up for determination of U.S. EPA 16 priority pollutant polycyclic aromatic hydrocarbons in solids by reversed-phase liquid chromatography with ultraviolet detection. Anal. Chim. Acta, 364, 1-11, 1998. 

Saim N, Dean JR, Abdullah MP, Zakaria Z (1998) An experimental design reproach Iot the determination of polycyclic aromatic hydrocarbons from highly contaminated soil using accelerated solvent extraction. Anal Chem 70 420-424 Shen J, Shao X (2005) A comparison of accelerated solvent extraction, Soxhiet extraction, and ultrasonic-assisted extraction for analysis of terpenoids and sterols in tobacco. Anal Bioanal Chem 383 1003-1008... 

Ultrasonic LSE is most applicable to the isolation of semivolatile and nonvolatile organic compounds from solid matrices such as soil, sediment, clays, sand, coal tar, and other related solid wastes. U-LSE is also very useful for the disruption of biological material such as serum or tissue. U-LSE can be coupled with solid-phase extraction (SPE) to give a very robust sample preparation method at relatively low cost in comparison to MAE and ASE approaches. The author has utilized U-LSE/SPE to isolate and recover 9,10-dimethyl-l,2-benzanthracene from animal bedding. A 89% recovery was obtained for bedding that was spiked with this polycyclic aromatic hydrocarbon (PAH) of interest to toxicologists (20). An ultrasonic horn and tip are immersed into a mixture of liquid extractant and solid sample and sonicated at some percent of full power for a finite length of time, either continuously or pulsed. 

Polycyclic aromatic hydrocarbons (PAHs) are produced through the incomplete combustion of various materials. Air-suspended particulates adsorb PAHs so air and subsequently soil and sand will also be contantinated. PAHs generally exhibit strong carcinogenic and mutagenic activity. For example, benzo[a]pyrene (B[a]P) is known as a carcinogenic compound. Synchronously excited fluorescence spectrometry has provided a multicomponent analysis of PAHs (135). After ultrasonic extraction of PAHs, e.g., B[a]P benzo[k]fluoranthene (B[k]F), chrysene (Chry), benzo[a]anthracene (B[a]A), pyrene (Py), perylene (Pery), and benzo[ghi]petylene (B[ghi]pery), from soils, they were separated by TLC on kieselguhr G layers mixed with 26% acetylated cellulose (135). Twelve PAHs... 

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