In the present study, ionic liquid-modified silica-coated magnetic nanoparticles (Fe₃O₄@SiO₂@IL) were synthesized and applied as adsorbents for extraction and determination of paraquat (PQ) followed ...by high-performance liquid chromatography. For assurance of the extraction efficiency, the obtained results were compared with those obtained by bared magnetic nanoparticles (MNPs). Experimental design and response surface methodology were used for optimization of different parameters which affect extraction efficiency of paraquat using both adsorbents. Under the optimized conditions, extraction recoveries in the range of 20–25 and 35–40 % with satisfactory repeatability values (RSDs%, n = 4) less than 5.0 % were obtained for bared MNPs and Fe₃O₄@SiO₂@IL, respectively. The limits of detection were 0.1 and 0.25 μg/L using Fe₃O₄@SiO₂@IL and bared MNPs, respectively. The linearity was obtained in the range of 0.25 to 25 μg/L and 0.5 to 25 μg/L for Fe₃O₄@SiO₂@IL and bared MNPs, respectively, with the coefficients of determination better than 0.9950. Finally, Fe₃O₄@SiO₂@IL was chosen as superior adsorbent due to more dispersion ability, higher extraction recovery, lower detection limit, as well as better linearity and repeatability. Calculated errors (%) were in the range of 3 to 10 % depicting acceptable accuracy for the analysis of PQ by the proposed method. Finally, the method was successfully applied for extraction and determination of PQ in some water and countryside soil samples.
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CEKLJ, 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
•COF adsorbent was composited with PPy nanoparticles in the presence of CTAB template.•Nanocomposite substrate was used to develop microextraction in packed syringe (MEPS).•Opiates were extracted and ...determined by MEPS coupled with HPLC/UV.•Urine samples were collected from a human and opiates were determined by the method.•COF-PPy-CTAB nanocomposite exhibits high extraction efficiency and a long lifetime.
This study aimed to develop microextraction in a packed syringe (MEPS) method for the determination of the three opiates in urine samples. Covalent organic framework-polypyrrole- cetyltrimethylammonium bromide (COF-PPy-CTAB) nanocomposite, as an appropriate and highly efficient adsorbent, was synthesized and applied to the MEPS process. The analytes were separated and extracted on the solid phase surface of the adsorbent through π stacking, hydrophobic, and host-guest interaction and then eluted by a desorbing solvent. After synthesizing the composite and using it in the syringe as a substrate for analyte adsorption, the parameters affecting the extraction of the analytes were optimized and the calibration curve was obtained according to the optimum conditions. The results were linear in the concentration range of 0.5–1000 μg L − 1 with a coefficient of determination greater than 0.9945. The limits of detection and quantification were obtained in the range of (0.1–1.0) and (0.5–5.0) μg L‒1, respectively. The precision of the work was obtained for a syringe in a day and between days and also syringe to syringe in the range of 4.4–6.1%, 6.5–8.1%, and 7.8–10.1%, respectively. The preconcentration factors of 17, 20, and 16 were obtained for codeine, papaverine, and naltrexone, respectively. Relative recoveries of the drugs from urine samples were in acceptable range of 94.4–100.6% for codeine, 99.3–103.1% for papaverine and 95.0–98.9% for naltrexone.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The ZIF-7@ZIF-67/PES composite was synthesized and applied for efficient dispersive solid-phase extraction of bisphenol A (BPA) and 2-phenyl phenol (BPh) from three real samples. The extracted ...analytes were separated and quantified using a high-performance liquid chromatography UV-Vis detector. The nanocomposite structure was examined through a series of techniques including field emission scanning electron microscopy, X-ray diffraction spectroscopy, Fourier transform infrared spectroscopy, energy-dispersive X-ray spectroscopy, and nitrogen adsorption-desorption experiment. For the first time, the ZIF-7@ZIF-67/PES was synthesized by an easy synthesis method, and it was applied in the field of extraction and separation of organic compounds. The composite was used for the extraction of BPA and BPh from a baby milk bottle, frozen water in a PET bottle, thermal paper followed by separation and determination of the analytes by high-performance liquid chromatography-ultraviolet detector and satisfactory results were obtained. Affecting parameters on the extraction efficiency of the analytes were optimized. Under optimal conditions, suitable linear range (2.0-500.0 μg L−1), limit of detection (0.6 μg L−1), repeatability (<3.1), and enhancement factors (150 and 182) were obtained for bisphenol A and 2-phenyl phenol, respectively.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The applicability of hollow fiber liquid phase microextraction (HF-LPME) for extraction and preconcentration of trace amounts of pioglitazone (PGL) as an anti-diabetic drug in biological fluids, ...prior to determination by high-performance liquid chromatography (HPLC), was evaluated. In this technique, the target drug was extracted into di-
n-hexyl ether immobilized in the wall pores of a porous hollow fiber from 10
mL of the aqueous sample (source phase, SP) with pH 8.0, and then back extracted into the receiving phase (RP) with pH 2.2 located in the lumen of the hollow fiber. The extraction occurred due to a pH gradient between the two sides of the hollow fiber. After extracting for a prescribed time, 24
μL of the RP solution was taken back into the syringe and injected directly into a HPLC instrument for quantification. The Taguchi orthogonal array (OAD) experimental design with an OA
16 (4
5) matrix was employed to optimize the HF-LPME conditions. Different factors affecting the HF-LPME efficiency such as the nature of organic solvent used to impregnate the membrane, pH of the SP and RP, stirring speed, extraction time and ionic strength were studied and optimized. Under the optimum conditions (di-
n-hexyl ether as membrane impregnation solvent, pHs of the SP and RP equal to 8.0 and 2.2, respectively, extraction time of 30
min, stirring speed of 500
rpm and 10% (w/v) NaCl for adjusting the ionic strength), preconcentration factor of 180, linear dynamic range (LDR) of 2.5–250
μg
L
−1 with good correlation of determination (
r
2
>
0.998) and limit of detection (LOD) of 1.0
μg
L
−1 were obtained for the target drug. The percent relative intra-day and inter-day standard deviations (RSDs%) based on five replicate determinations were 4.7 and 15%, respectively. Once LPME was optimized, the performance of the proposed technique was evaluated for the determination of PGL in different types of biological fluids such as plasma and urine samples. The results showed that the proposed HF-LPME method could be successfully applied to determine trace amounts of PGL in biological samples.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
The electrochemical fiber coating (EFC) technique was used for the preparation of dodecylsulfate-doped polypyrrole (PPy-DS), and applied as a new fiber for solid-phase microextraction (SPME) ...procedures. PPy-DS film was directly electrodeposited on the surface of a platinum wire from an aqueous solution containing pyrrole and sodium dodecylsulfate, using cyclic voltammetry (CV). The effect of polymerization conditions and type of dopants on the thermal stability, adhesion and extraction characteristics of the fiber were investigated. The electron microscopy imaging of PPy-DS film suggested that the surface fiber coating was well-distributed with a porous structure. The fiber coating can be prepared easily in a reproducible manner, and it is inexpensive and has a stable performance at high temperatures (up to the 300
°C). The extraction properties of the fiber to eight polycyclic aromatic hydrocarbons (PAHs) were examined, using a headspace-SPME (HS-SPME) device coupled with gas chromatography-flame ionization detection (GC-FID) and gas chromatography-mass spectrometry (GC-MS). The results revealed study shows that PPy-DS as a SPME fiber coating is suitable for the successful extraction of PAHs. The effects of the extraction parameters including exposure time, sampling temperature, salt concentration, and stirring rate on the extraction efficiency have been studied. A satisfactory reproducibility for extractions from spiked water samples at PPb-level with R.S.D.
<
7.6% (
n
=
7) was obtained. The calibration graphs were linear in the range of 0.5–100
ng
ml
−1 and detection limits for the selected PAHs were between 0.05–0.16
ng
ml
−1. Comparing the HS-SPME results for extraction and determination of PAHs using PPy-DS fiber with the corresponding literature data using PDMS fiber shows that the proposed fiber has a better detection limit for low molecular weight PAHs. The life span and stability of PPy-DS fiber is good and it can be used more than 50 times at 250
°C without any significant change in sorption properties.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
An electrochemically controlled in-tube solid phase microextraction method has been developed for the extraction of ultra-trace amounts of three groups of chlorophenols (CPs): mono-chlorophenols, ...di-chlorophenols and tri-chlorophenols in rain, river and tap water samples. Determination of the extracted CPs was performed by high performance liquid chromatography and UV detection. A new polypyrrole/Nafion composite coating was electrochemically synthesized on the inner surface of the stainless steel capillary as a working electrode (anode) for the electrochemical extraction of chlorophenols from water samples. By passing the sample solution over the inner surface of the coated electrode, the chlorophenols could be extracted by applying a positive potential under flow conditions. This method is an ideal sample preparation technique because it is easy to automate, solvent-less, and inexpensive. Some important experimental parameters that could affect the extraction and separation of the analytes, such as the extraction and desorption voltages, the pH of sample solution, the extraction and desorption times and the flow rates of the sample solution and eluent were investigated and optimized. Under optimal conditions, the limits of detection were in the range of 0.07–0.20 μg L −1 . This method showed good linearity for chlorophenols in the range of 0.20–500 μg L −1 , with coefficients of determination greater than 0.9984. The inter- and intra-assay precision (RSD%, n = 3) was in the range of 5.4–6.8% and 4.0–5.9% at three concentration levels of 2, 10 and 20 μg L −1 , respectively. The validated method was successfully applied for the analysis of 2-chloro-, 4-chloro-, 2,3-dichloro-, 2,4-dichloro-, 2,3,6-trichloro-, and 2,4,6-trichloro phenols in water samples.
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IJS, KILJ, NUK, UL, UM, UPUK
•An effective on-chip electromembrane extraction (CEME) was designed and coupled with HPLC.•This design does not require a syringe pump, so the system is simple and easy to handle.•The method was ...applied for simultaneous extraction and determination of acidic and basic analytes.•Efficient parameters on CEME of ibuprofen, disopyramide and lidocaine were optimized.•The preconcentration factors higher than 7.4 and RSDs% < 3.9% were obtained.
In the present study, a new chip was designed for simultaneous electromembrane extraction (EME) of acidic and basic analytes. The method followed by the HPLC-UV analysis, was used for simultaneous extraction and determination of trace amounts of target analytes with different properties. Ibuprofen (IBU), as an acidic model analyte, and disopyramide (DIS) and lidocaine (LID), as basic model analytes, were selected. The chip was composed of three polymethylmethacrylate (PMMA) plates. The chamber for the sample solution was set in the middle plate. Two other chambers were carved on the other plates and they were acted as two acceptor phases’ reservoirs. Two stainless steel electrodes, which were responsible for applying a DC electrical potential on both sides of the supported liquid membranes (SLMs), were placed in the bottom of acceptor phases chambers and connected to a power supply. The two porous polypropylene membrane sheets, which were impregnated with different organic solvents, were used to separate the plates. Effective parameters such as SLM composition (1-octanol for acidic analyte and NPOE+5%DEHP for basic analytes), pH of donor phase and acceptor phases, applied voltage across SLM, and extraction time were optimized. Under the optimized conditions, the calibration curves were linear with coefficient of determinations (R2) higher than 0.991 in the water, urine, and blood plasma samples. The obtained LODs were less than 5.0 µg L−1 and 1 µg L−1 for the basic and acidic analytes, respectively. The results demonstrated that on-chip EME would be used most effectively for extraction and determination of IBU, DIS, and LID in biofluids.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The authors describe an efficient method for microextraction and preconcentration of trace quantities of cationic nitrogen compounds, specifically of anilines. It relies on a combination of ...electrochemically controlled solid-phase microextraction and on-line in-tube solid-phase microextraction (SPME) using polypyrrole-coated capillaries. Nanostructured polypyrrole was electrically deposited on the inner surface of a stainless steel tube and used as the extraction phase. It also acts as a polypyrrole electrode that was used as a cation exchanger, and a platinum electrode that was used as the anode. The solution to be extracted is passed over the inner surface of the polypyrrole electrode, upon which cations are extracted by applying a negative potential under flow conditions. This method represents an ideal technique for SPME of protonated anilines because it is fast, easily automated, solvent-free, and inexpensive. Under optimal conditions, the limits of detection are in the 0.10–0.30 μg L‾
1
range. The method works in the 0.10 to 300 μg L‾
1
concentration range. The inter- and intra-assay precisions (RSD%; for
n
= 3) range from 5.1 to 7.5 % and from 4.7 to 6.0 % at the concentration levels of 2, 10 and 20 μg L‾
1
, respectively. The EC-in-tube SPME method was successfully applied to the analysis of methyl-, 4-chloro-, 3-chloro and 3,4-dichloroanilines in (spiked) water samples.
Graphical Abstract
ᅟ
Cloud point method was applied for the simultaneous extraction and preconcentration of trace amounts of gold and palladium. The extraction of analytes was performed in the presence of ...1,8-diamino-4,5-dihydroxy anthraquinone as chelating agent and Triton X-114 as a non-ionic surfactant. After phase separation, the surfactant-rich phase was diluted with concentrated HNO
3 (65%, w/w) and the analytes concentrations were determined by inductively coupled plasma-optical emission spectrometry (ICP-OES). The variables affecting the complexation and extraction conditions were optimized and under the optimum conditions (i.e. pH 6.5, 2.2
×
10
−4
mol
l
−1 chelating agent, 0.15% (w/v) of Triton X-114, equilibration temperature 55
°C, centrifuge at 3500
rpm), quantitative extraction of Au(III) and Pd(II) from 100
ml of the aqueous solution was performed. The calibration curves were linear in the range of 0.5–1000
μg
l
−1 with detection limits of 0.5 and 0.3
μg
l
−1 and the enrichment factors were 8.6 and 20.2 for Au and Pd, respectively. Also the precision (%RSD) for eight replicate determinations of the analytes was better than 5%. Finally, the proposed method was successfully applied for the determination of Au and Pd in mine stones and standard reference materials (SRM).
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Electromembrane extraction coupled with high‐performance liquid chromatography (HPLC) and ultraviolet (UV) detection was developed for the determination of levamisole in some human biological fluids. ...Levamisole migrated from 4 mL of different acidized biological matrices, through a thin layer of 2‐nitrophenyl octyl ether containing 5% tris‐(2‐ethylhexyl) phosphate immobilized in the pores of a porous hollow fiber, into a 20‐μL acidic aqueous acceptor solution present inside the lumen of the fiber. The parameters influencing electromigration were investigated and optimized. Within 15 min of operation at 200 V, levamisole was extracted from different biological fluid samples with recoveries in the range of 59–65%, which corresponded to preconcentration factors in the range of 118–130. The calibration curves showed linearity in the range of 0.5–10, 0.2–10 and 0.1–10 μg/mL for plasma, urine and saliva, respectively. Limits of detection of 0.1, 0.07 and 0.05 μg/mL and limits of quantification of 0.5, 0.2 and 0.1 μg/mL were obtained for plasma, urine and saliva, respectively. The relative standard deviations of the analysis were found to be in the range of 5.6–9.7% (n=3). Electromembrane extraction was successfully processed for determination of levamisole in plasma, urine and saliva samples.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
