An electropolymerized aniline-based fiber coating for solid phase microextraction of phenols from water

In situ growth and phenyl functionalization of titania nanoparticles coating for solid-phase microextraction of ultraviolet filters in environmental water samples followed by high performance liquid chromatography-UV detection

Based on TiO2-nanoparticles coating fabricated by a one-step anodization method on titanium wire substrate, a novel phenyl functionalized solid-phase microextraction (SPME) fiber coating was prepared by simple and rapid in situ chemical assembling technique between the fiber surface titanol groups and trichlorophenylsilane reaction. The as-fabricated fiber exhibited good extraction capability for some UV filters and was employed to determine the ultraviolet (UV) filters in combination with high performance liquid chromatography-UV detection (HPLC-UV). The main parameters affecting extraction performance were investigated and optimized. Under the optimized conditions, the developed method was applied to detect several UV filters at trace concentration levels with only 8 mL of sample volume. They were determined in the range from 0.005 to 25 μg L(-1) with detection limits (S/N=3) from 0.1 to 50 ng L(-1). The relative standard deviations (RSDs) for single fiber repeatability varied from 4.6 to 6.5% (n=5) and fiber-to-fiber reproducibility (n=5) ranged from 5.5 to 9.1%. The linear ranges spanned two-four magnitudes with correlation coefficients above 0.9990. Five real water samples including four Yellow River water samples and one rain water sample were determined sensitively with good recoveries ranging from 86.2 to 105.5%. The functionalized fiber coating performed good reproducible manner, high mechanical strength, good stability and long service life. Moreover, this study proposed an efficient sample pretreatment method for the determination of UV filters from environmental water samples.

Electrochemically controlled in-tube solid phase microextraction of naproxen from urine samples using an experimental design

Electrochemically controlled in-tube SPME approach, which increased the sensitivity and decreased the extraction time, was reported.

Microextraction in urine samples for gas chromatography: a review

Since the complexity origin of biological samples, the research trends have been directed to the development of new miniaturized sample preparation techniques. This review provides a comprehensive survey of past and present microextraction methods followed by GC analysis for preconcentration and determination of various analytes in urine samples. These techniques have been classified in three general groups, including liquid-, solid- and membrane-based techniques. The principal of different microextraction methods that are located in each general group as well as their various extraction modes and the recent developments introduced for them has been presented. Subsequently, a comparison survey has been carried out among different microextraction techniques and finally a future perspective has been predicted based on the existing literature.

In situ anodic growth of rod-like TiO2 coating on a Ti wire as a selective solid-phase microextraction fiber

A novel rod-like TiO₂ based SPME coating was directly fabricated by in situ anodization of Ti wire (Fig. 1). It has larger surface area and longer service time for sensitive determination of ultraviolet filters in environmental water samples.

Electropolymerized fluorinated aniline-based fiber for headspace solid-phase microextraction and gas chromatographic determination of benzaldehyde in injectable pharmaceutical formulations

In this study, a simple method was developed and validated to detect trace levels of benzaldehyde in injectable pharmaceutical formulations by solid-phase microextraction coupled with gas chromatography-flame ionization detector. Polyaniline was electrodeposited on a platinum wire in trifluoroacetic acid solvent by cyclic voltammetry technique. This fiber shows high thermal and mechanical stability and high performance in extraction of benzaldehyde. Extraction and desorption time and temperature, salt effect and gas chromatography parameters were optimized as key parameters. At the optimum conditions, the fiber shows good linearity between peak area ratio of benzaldehyde/3-chlorobenzaldehyde and benzaldehyde concentration in the range of 50-800 ng/mL with percent relative standard deviation values ranging from 0.75 to 8.64% (n = 3). The limits of quantitation and detection were 50 and 16 ng/mL, respectively. The method has the requisite selectivity, sensitivity, accuracy and precision to assay benzaldehyde in injectable pharmaceutical dosage forms.

Quantification of PAHs and chlorinated compounds by novel solid-phase microextraction based on the arrays of tin oxide nanorods

The results of an innovative study on a new and highly efficient stationary phase based on the SnO2 nanorods coating on fused silica have been reported in this paper. SnO2 nanorods have been grown on fused silica fibers using a hydrothermal process. The extraction properties of the fiber were investigated using headspace solid-phase microextraction (HS-SPME) mode coupled with gas chromatography-mass spectrometry detection for 1,4-dichloro-2-nitrobenzene, biphenyl, and acenaphthene. The effect of different variables on extraction efficiency was studied simultaneously using Box-Behnken method as experimental design. The variables of interest in the HS-SPME were salt effect, adsorption temperature, extraction, and desorption time. Under optimal conditions, the calibration curves were linear up to 10(2)-10(5) ng L(-1) (R(2) > 0.998) with detection limits of 10(-3), 10(-1), and 10 ng L(-1) for acenaphthene, biphenyl, and 1,4-dichloro-2-nitrobenzene, respectively. The relative standard deviations for single fiber and fiber to fiber were less than 9.8 and 12.5 %, respectively. The high stability of the SnO2 nanostructure coating is proved at relatively high temperatures (up to 300 °C) with a high extraction capacity and long lifespan (more than 100 times). By applying the proposed technique, promising recoveries (93-98 %) were obtained in the analysis of environmental water samples.

Determination of 16 polycyclic aromatic hydrocarbons in water using fluorinated polyaniline-based solid-phase microextraction coupled with gas chromatography

The study on the performance of a fluorinated polyaniline (PANI) as a fiber coating for solid-phase microextraction (SPME) had been reported and 16 polycyclic aromatic hydrocarbons (PAHs) were selected to evaluate the performance of this fiber. Various parameters including sample volume, extraction temperature, time of desorption and extraction, pH and ionic strength were investigated intensively. A direct comparison between PANI-SPME fiber and commercial fiber was conducted. The results showed that the PANI-SPME coating had high affinity towards target compounds and the proposed method was successfully applied for the detection of real samples: rainfall and Taihu Lake water collected from Southern China. The whole PANI-SPME-GC method offers acceptable accuracy, precision and sensitivity and low detection limits, which is applicable to monitor trace levels of PAHs in real water bodies.

Preparation and Application of Multiwalled Carbon Nanotubes Microspheres/Poly(ethylene glycol) Coated Fiber for SPME

In this context,the sol-gel approach to the preparation of solid-phase microextraction fibers is applied for extracting of benzene and mathanol from enviromental water samples.Therefore,two different substances such as PEG and MWCNTs is added to the coating.PEG/MWCNTs fibers are prepared using sol-gel technology as a process.MWCNTs is immobilized as microspheres in the pores of PEG coating using Scanning Electron Microscope(SEM).At last, the results show that PEG/MWCNTs fibers are higher extraction efficiency than PEG fibers. Several factors also are considered and optimized,such as extraction temperature, extraction time,inoic strength,stirring speed,desorption temperature and desorption time.LOD(S/N=5) and LOQ(S/N=10) for sol-gel PEG/MWCNTs fibers for extraction of benzene and methanol is 1µg/L and 2µg/L, linear range is 2-2800µg/mL and 2-3000µg/L, linear correlation coefficient is 0.9937 and 0.9940, the RSDs (RSD, n = 7) is 5.1%. and 6.7%, respectively.

Aniline-silica nanocomposite as a novel solid phase microextraction fiber coating

A new unbreakable solid phase microextraction (SPME) fiber coating based on aniline-silica nanocomposite was electrodeposited on a stainless steel wire. The electropolymerization process was carried out at a constant deposition potential, applied to the corresponding aqueous electrolyte containing aniline and silica nanoparticles. The scanning electron microscopy (SEM) images showed the non-smooth and the porous surface structure of the prepared nanocomposite. The applicability of the new fiber coating was examined by headspace-solid phase microextraction (HS-SPME) of some environmentally important polycyclic aromatic hydrocarbons (PAHs), as model compounds, from aqueous samples. Subsequently, the extracted analytes were transferred into a gas chromatography (GC) by thermal desorption. Parameters affecting the synthesizing and extraction processes including the voltage of power supply, the weight ratio of components, the time of electrodeposition, extraction time and temperature, the ionic strength, and desorption temperature and time were optimized. Eventually, the developed method was validated by gas chromatography-mass spectrometry (GC-MS). At the optimum conditions, the relative standard deviation (%RSD) values for a double distilled water spiked with the selected PAHs at 40 ng L(-1) were 6-13% (n=3) while the limit of detection (LOD) results were between 1 and 3 ng L(-1). The calibration graphs were linear in the concentration range from 20 to 4000 ng L(-1) (R(2)>0.995). Finally the developed method was applied to the analysis of Kalan dam, rain and tap water samples and the relative recovery values were found to be in the range of 76-109%, under optimized conditions. In addition, the synthesis of the nanocomposite coating was carried out conveniently while it is rather inexpensive, easy, simple, rapid and highly durable and can be used frequently.