•Polyaniline (PAN) and polypyrrole (PPY) can be suitable coatings for SPME fibers.•PAN–PPY nano composite was electrochemically deposited on inner surface of stainless steel tube.•On-line in-tube ...SPME followed by HPLC was developed for extraction of parabens.•Several important factors affecting extraction efficiency were investigated and optimized.•The method was applied for analysis of the parabens in water, milk, and juice samples.
In this work, a novel and efficient on-line in-tube solid phase microextraction method followed by high performance liquid chromatography was developed for preconcentration and determination of trace amounts of parabens. A nanostructured polyaniline–polypyrrole composite was electrochemically deposited on the inner surface of a stainless steel tube and used as the extraction phase. Several important factors that influence the extraction efficiency, including type of solid-phase coating, extraction and desorption times, flow rates of the sample solution and eluent, pH, and ionic strength of the sample solution were investigated and optimized. Under the optimal conditions, the limits of detection were in the range of 0.02–0.04μgL−1. This method showed good linearity for parabens in the range of 0.07–50μgL−1, with coefficients of determination better than 0.998. The intra- and inter-assay precisions (RSD%, n=3) were in the range of 5.9–7.0% and 4.4–5.7% at three concentration levels of 2, 10, and 20μgL−1, respectively. The extraction recovery values for the spiked samples were in the acceptable range of 80.3–90.2%. The validated method was successfully applied for analysis of methyl-, ethyl-, and propyl parabens in some water, milk, and juice samples.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
► Electromembrane surrounded solid phase microextraction (EM-SPME) was introduced. ► Electrical potential was applied for 20min and drugs were adsorbed on pencil lead. ► Effective parameters on the ...extraction efficiency of the drugs were optimized. ► Intra- and inter-assay precisions ranged between 4.0–8.5% and 7.5–12.2%. ► The method was applied for analyzing amitriptyline and doxepin in urine and plasma.
In the present work, electromembrane surrounded solid phase microextraction (EM-SPME) is introduced for the first time. The organic liquid membrane, which consists of 2-nitrophenyl octyl ether (NPOE), was immobilized in the pores of a hollow fiber (HF) and the basic analytes migrated in an electrical field from aqueous sample solution through the liquid membrane and into aqueous acceptor phase and then they were adsorbed on the solid sorbent, which acts as the cathode. Effective parameters such as composition of organic liquid membrane, pH of donor and acceptor phases, applied voltage and extraction time were optimized for extraction of amitriptyline (AMI) and doxepin (DOX) as model analytes and figures of merit of the method were investigated in pure water, human plasma, and urine samples. To extract the model analytes from 24mL neutral sample solution across organic liquid membrane and into aqueous acceptor phase, 120V electrical potential was applied for 20min and finally the drugs were adsorbed on a carbonaceous cathode. Regardless of high sample cleanup, which make the proposed method suitable for the analysis of drugs from complicated matrices, extraction efficiencies in the range of 3.1–11.5% and good detection limits (less than 5ngmL−1) with admissible repeatability and reproducibility (intra- and inter-assay precisions ranged between 4.0–8.5% and 7.5–12.2%, respectively) were obtained from different extraction media. Linearity of the method was studied in the range of 2.0–500.0ngmL−1 and 5.0–500.0ngmL−1 for AMI and DOX, respectively and coefficient of determination higher than 0.9947 were achieved. Finally, the proposed method was applied for the analysis of AMI and DOX in real samples.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Hollow-fiber liquid-phase microextraction (HF-LPME) and electromembrane extraction (EME) are miniaturized extraction techniques, and have been coupled with various analytical instruments for trace ...analysis of heavy metals, drugs and other organic compounds, in recent years. HF-LPME and EME provide high selectivity, efficient sample cleanup and enrichment, and reduce the consumption of organic solvents to a few micro-liters per sample. HF-LPME and EME are compatible with different analytical instruments for chromatography, electrophoresis, atomic spectroscopy, mass spectrometry, and electrochemical detection. HF-LPME and EME have gained significant popularity during the recent years. This review focuses on hollow fiber based techniques (especially HF-LPME and EME) of heavy metals and pharmaceuticals (published 2017 to May 2019), and their combinations with atomic spectroscopy, UV-VIS spectrophotometry, high performance liquid chromatography, gas chromatography, capillary electrophoresis, and voltammetry.
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•Review article focused on hollow fiber liquid-phase microextraction and electromembrane extraction.•Focus on heavy metal and pharmaceutical applications.•Covers research articles published in 2017–2019.
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FFLJ, GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, ODKLJ, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The current study presents a periodic mesoporous organosilica (PMO) with a high surface area and uniform-porosity material. The PMO materials were successfully synthesized and modified. The resultant ...material was characterized by different characterization techniques. The prepared PMO was immobilized on a stainless steel wire surface and was evaluated for headspace solid-phase microextraction of the ultra-trace amount of phthalate esters from saliva and polyethylene terephthalate containers which were in contact with hot and cold water. Separation and determination of the phthalate esters (PEs) were performed by the GC–FID and GC–MS instruments. The key parameters affecting the extraction efficiencies, including extraction temperature, extraction time, ionic strength, and desorption temperature and time, were investigated and optimized. Under optimum conditions, the repeatability for one fiber (
n
= 7) was 4.8–8.7%, and fiber-to-fiber reproducibility (
n
= 3) was 7.5–10.6% for the extracted compounds. The limits of detection of the developed method for the studied compounds were between 0.01 and 1 μg L
−1
. The results showed suitable coefficients of determination (
R
2
≥ 0.99) for all of the analytes in the 0.05–300 μg L
−1
calibration range. Acceptable recovery values of 91–107%, 82–110%, and 98–104% were obtained in saliva, polyethylene terephthalate containers hot water, and cold water, respectively.
Graphical abstract
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
In this work, a "packed in-tube" configuration has been developed for packed in-tube solid phase microextraction followed by high performance liquid chromatography. Cobalt/chromium-layered double ...hydroxide (Co/Cr (NO
3
−
)-LDH) nano-sheets were synthesized by a simple coprecipitation method and were employed as a packed in-tube solid phase microextraction sorbent. The developed method and the synthesized sorbent were applied for the extraction and preconcentration of two different groups of acidic pesticides with different charges including an acidic herbicide (haloxyfop, anionic form) and insecticide (hexaflumuron, neutral form) from aqueous solutions. The extraction ability of the developed method was investigated by X-ray diffraction (XRD), scanning electronic microscopy (SEM), and Fourier transform infrared spectroscopy (FT-IR). Characterization of the LDH powder using XRD and SEM images showed that it consists of a large number of inter-crossed and curved nano-sheets with plate-like morphology. Several important factors affecting the extraction efficiency such as the pH of the sample solution, the extraction/desorption time, the flow rate of the sample solution and type of desorption solvent were optimized. Under the optimized conditions, good intra- and inter-assay precisions (RSD%,
n
= 5) in the range of 3.3-3.9% and 4.2-4.9%, respectively, were obtained. Also, the limits of detection were in the range of 0.05-0.08 μg L
−1
. This method showed good linearity for the pesticides in the range of 0.1-500 μg L
−1
with coefficients of determination better than 0.9984 in water samples. This validated method was successfully applied in the analysis of haloxyfop and hexaflumuron in some water samples. Finally, it can be said that this method has the potential to be a general and reliable alternative for the analysis of acidic pesticides in anionic and neutral forms in real water matrices.
Cobalt/chromium-layered double hydroxide (Co/Cr (NO
3
−
)-LDH) nano-sheets were employed as a packed in-tube solid phase microextraction sorbent for efficient extraction of acidic pesticides from water samples.
The present research is an attempt to expand the recently reported microextraction on screw method. For this purpose, polyacrylonitrile/calcined ZnMgAl-LDH nanofiber was fabricated by the ...electrospinning technique on the surface of a screw. It was applied to the extraction of organophosphorus pesticides (OPP) from agricultural samples. The separation and determination of OPPs were carried out by gas chromatography–mass spectrometry. The characterization of the fabricated nanofiber was performed utilizing Fourier transform infrared spectroscopy, field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray diffraction instruments. Effective parameters on the extraction efficiency of the analytes including sample pH, ionic strength, sample flow rate and number of cycles, type, volume, and flow rate of desorption solvent were optimized by one-variable-at-a-time method. Under optimized conditions, the limits of detection were 0.03 and 0.07 μg L
−1
for diazinon and chlorpyrifos, respectively. This method showed wide linearity in the range 0.10–1000 μg L
−1
for diazinon and 0.25–1000 μg L
−1
for chlorpyrifos with
R
2
> 0.996. The intra- and inter-day precisions (RSD%,
n
= 3) were ≤ 6.4% and ≤ 7.7%, respectively. Also, RSD% values less than 11.1% were obtained for screw-to-screw reproducibility. The applicability of the method for the extraction and determination of the analytes in complex agricultural environments such as cabbage, potato, tomato, cucumber, and beetroot was investigated. The results led to acceptable relative recoveries in the range 81.0–108.2%.
Graphical abstract
Electromembrane extraction (EME) coupled with high performance liquid chromatography and ultraviolet detection was developed for determination of amphetamine-type stimulants in human urine samples. ...Amphetamines migrated from 3
mL of different human urine matrices, through a thin layer of 2-nitrophenyl octyl ether (NPOE) containing 15% tris-(2-ethylhexyl) phosphate (TEHP) immobilized in the pores of a porous hollow fiber, and into a 15
μL acidic aqueous acceptor solution present inside the lumen of the fiber. Equilibrium extraction conditions were obtained after 7
min of operation. Experimental design and response surface methodology (RSM) were used for optimization of EME parameters. Under optimal conditions, amphetamines were effectively extracted with recoveries in the range of 54–70%, which corresponded to preconcentration factors in the range of 108–140. The calibration curves were investigated in the range of 0–7
μg
mL
−1 and good linearity was achieved with a coefficient of estimation better than 0.991. Detection limits and inter-day precision (
n
=
3) were less than 0.01
μg
mL
−1 and 11.2%, respectively.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
By a simple and low-cost method, zeolitic imidazole framework-67 was synthesized. It was used as a solid-phase microextraction coating. The solid-phase microextraction was used for the extraction of ...1-octanol, 1-nonanol, 1-decanol and 1-undecanol from the headspace of an aqueous solution. Separation and determination of the analytes were performed by a gas chromatography followed with a flame ionization detector. Several techniques such as field emission scanning electron microscopy, X-ray diffraction spectroscopy, Fourier transform infrared spectroscopy analysis, energy-dispersive X-ray spectroscopy, thermal gravimetric analysis and nitrogen adsorption–desorption experiments have been utilized for characterization of the coating material. The effective parameters on the extraction of the alcohols were investigated and optimized. Under the optimum conditions, four kinds of alcohol including 1-octanol, 1-nonanol, 1-decanol, and 1-undecanol were extracted and determined with linear ranges (0.5–100.0 μg L
−1
with
R
2
≥ 0.9945), limits of quantification of 0.5 µg L
−1
and limits of detection that were calculated based on 3(S
d
)
blank
/m (0.17 µg L
−1
) for all of the analytes. The average repeatability and fiber-to-fiber reproducibility were 7.7% and 11.7%, respectively. Additionally, 1-octanol, 1-nonanol, 1-decanol, and 1-undecanol in alcoholic beverages were determined with a mean recovery of 90.9–92.5% and relative standard deviations less than 9.8%.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
In the present work, an automated on-line electrochemically controlled in-tube solid-phase microextraction (EC-in-tube SPME) coupled with HPLC-UV was developed for the selective extraction and ...preconcentration of indomethacin as a model analyte in biological samples. Applying an electrical potential can improve the extraction efficiency and provide more convenient manipulation of different properties of the extraction system including selectivity, clean-up, rate, and efficiency. For more enhancement of the selectivity and applicability of this method, a novel molecularly imprinted polymer coated tube was prepared and applied for extraction of indomethacin. For this purpose, nanostructured copolymer coating consisting of polypyrrole doped with ethylene glycol dimethacrylate was prepared on the inner surface of a stainless-steel tube by electrochemical synthesis. The characteristics and application of the tubes were investigated. Electron microscopy provided a cross linked porous surface and the average thickness of the MIP coating was 45 μm. Compared with the non-imprinted polymer coated tubes, the special selectivity for indomethacin was discovered with the molecularly imprinted coated tube. Moreover, stable and reproducible responses were obtained without being considerably influenced by interferences commonly existing in biological samples. Under the optimal conditions, the limits of detection were in the range of 0.07–2.0 μg L−1 in different matrices. This method showed good linearity for indomethacin in the range of 0.1–200 μg L−1, with coefficients of determination better than 0.996. The inter- and intra-assay precisions (RSD%, n = 3) were respectively in the range of 3.5–8.4% and 2.3–7.6% at three concentration levels of 7, 70 and 150 μg L−1. The results showed that the proposed method can be successfully applied for selective analysis of indomethacin in biological samples.
An automated on-line method for selective extraction and preconcentration of the indomethacin in biological samples was developed. Display omitted
•Molecularly imprinted polymer coated in-tube solid-phase microextraction was prepared.•Electrochemically controlled in-tube solid-phase microextraction-HPLC was developed.•Method was applied for selective extraction of indomethacin from biological samples.•The effective parameters on the extraction efficiency of indomethacin were optimized.•The method showed good linearity for indomethacin in the range of 0.1–200 μg L−1.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
During the last few decades, many studies have focused on the development of environmentally friendly, efficient, and miniaturized sample preparation methods. In this study, solid-phase ...microextraction and electromembrane extraction methods were integrated to take advantage of both methods and achieve higher extraction recoveries and clean-up. In this regard, Cu/Cr layered double hydroxide was dispersed in a poly(methacrylic acid-co-ethylene glycol dimethacrylate) polymerization mixture, and in situ polymerization was performed in the acceptor phase channel. Thereafter, EME-SPME on a chip was developed to extract non-steroidal anti-inflammatory drugs. The obtained limits of detection were 0.1–0.25 ng mL−1. Under evaluation of this method, extraction recoveries were obtained in the range of 83.34–90.87%, which corresponded to preconcentration factors of 56–61. The method was applied for the extraction of the drugs from real samples such as breast milk, urine, and plasma, and satisfactory results were obtained.
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