Ionic liquid surfactants are a class of ionic liquids (ILs), which can form micelles in the aqueous solution. In this paper, we demonstrate a novel extracting system based on the use of IL surfactants in ultrasonic-assisted extraction followed by HPLC analysis. No organic solvents were used in the extraction, making this method environmentally friendly and more attractive than the conventional organic solvent-based extraction methods. As an example, this method was applied to determine tanshinones in Chinese herbal medicine Salvia miltiorrhiza bunge. The effect of the carbon chain length of the IL cation, as well as other influencing factors on ultrasonic-assisted extraction, was investigated in detail. Under the optimized conditions, satisfactory extraction efficiency was achieved with the recoveries ranging from 87.5 to 107.6%, and the RSDs were lower than 6%. This work shows a promising prospect of the IL surfactants in the extraction of active ingredients from herbs.

Triphenylamine (TPA)-functionalized magnetic microspheres (Fe(3)O(4)/SiO(2)/TPA) were prepared and applied as solid phase extraction (SPE) adsorbents for the analysis of polycyclic aromatic hydrocarbons (PAHs) in environmental samples in combination with high-performance liquid chromatography (HPLC). The magnetic solid-phase extraction (MSPE) conditions affecting the extraction efficiency were optimized, including elution solvent, standing time, amount of sorbent, and salt concentration. Due to the strong π-π conjugate effect between the benzene rings of TPA and PAHs, high extraction efficiency was achieved with spiked recoveries of 80.21-108.33% and relative standard deviations (RSD) of less than 10%. Good linearities (R(2) > 0.997) for all calibration curves were obtained with low limits of detection (LOD) of 0.25, 0.5, 0.5, 3.75, 0.2 and 0.04 ng L(-1) for anthracene, fluoranthene, pyrene, chrysene, benzo[b]fluoranthene and benzo[k]fluoranthene, respectively. The achieved results indicate the applicability of Fe(3)O(4)/SiO(2)/TPA as MSPE adsorbents.

Magnetic microsphere confined ionic liquid was synthesized by covalently bonding N-methylimidazolium on magnetic microspheres. The functionalized magnetic microspheres were characterized by Fourier transform infrared (FT-IR) spectrometry, thermogravimetric analysis (TGA) and scanning electron microscopy (SEM). The prepared material was used for the preconcentration of three chlorophenols (CPs) in water combined with high-performance liquid chromatography (HPLC). Several conditions that probably affected the extraction efficiency such as standing time, eluent and its volume, sample pH and volume, were optimized. Under the optimal conditions, good recoveries (70.3-88.8%) were achieved with satisfactory relative standard deviations (RSDs) of less than 6.0%. The limits of detection for the three CPs were 0.20-0.35 μg L(-1). The results indicated that the ionic liquid-functionalized magnetic microspheres show significant promise for the analysis of CPs in environmental samples.

C18-functionalized magnetic microspheres synthesized in a three-stage system and characterized by Fourier transform infrared (FTIR) spectroscopy and SEM were applied for clean-up and enrichment of polycyclic aromatic hydrocarbons (PAHs) in soil samples combined with ultrasonication extraction. Magnetic solid-phase extraction (MSPE) parameters, such as elution solvents, amounts of sorbents, enrichment time and organic modifier, were optimized together with ultrasonication time and extraction solvents. Under the optimal conditions, the developed method provided spiked recoveries of 63.2-92.8% with RSDs of less than 6.4% and limits of detection were 0.5-1.0 ng/g. This new method provides several advantages, such as high extraction efficiency, convenient extraction procedure and short analysis times. Finally, the method was successfully applied to the determination of polycyclic aromatic hydrocarbons in soil samples.

Titanium wire-based solid phase extraction (SPE) is developed for the analysis of six different polycyclic aromatic hydrocarbons in water samples with coupling with high performance liquid chromatography. The adsorbent is a Ti wire on which TiO(2) nanotubes are first formed by anodization and then Au nanoparticles and n-octadecanethiol are modified. The surface composition and structure of the adsorbent were characterized in detail using field emission scanning electron microscope and Fourier transform infrared spectroscopy. The main parameters affecting the extraction efficiency, such as the volume of the organic modifier, extraction time, elution solvent, and desorption time were optimized. Good linearities ranging from 0.025 to 30 μg L(-1) with correlation coefficients (R(2)) ranging from 0.9964 to 0.9999 and low limits of detection were obtained in spiked water samples. Furthermore, this method was successfully applied in the analysis of real river water samples with recoveries in the range of 75.33-115.83% and relative standard deviations ranging from 4.85 to 10.77%. The developed SPE can be a particularly convenient means of sample pretreatment for environmental water samples.