In the present study, a simple and efficient preconcentration method was developed using carrier mediated three phase liquid phase microextraction prior to HPLC–UV for simultaneous extraction and ...determination of trace amounts of highly hydrophilic tetracycline antibiotics including tetracycline (TCN), oxytetracycline (OTCN) and doxycycline (DCN) in bovine milk, human plasma and water samples. For extraction, 11.0
mL of the aqueous sample containing TCNs and 0.05
M Na
2HPO
4 (9.1
≤
pH
≤
9.5) was filled into a 12.0-mL vial. The solution of 1-octanol (containing 10% (w/v) of Aliquat-336 as carrier) was immobilized in the pores of a porous polypropylene hollow fiber. Aqueous receiving phase (RP, 24
μL of 0.1
M H
3PO
4 and 1.0
M NaCl with pH
=
1.6) was located inside the lumen of hollow fiber and the fiber was transferred into the aqueous sample. After the extraction period, the receiving phase was directly injected into HPLC. In order to obtain high extraction efficiency, the parameters affecting the liquid phase microextraction were evaluated and optimized. Under the optimized conditions, the calibration curves were linear in the range of 0.5–1000
μg
L
−1 for TCN and OTCN, and in the range of 5–1000
μg
L
−1 for DCN with good linearity (
r
2
>
0.995). Finally, applicability of the proposed method was successfully confirmed by extraction and determination of the drugs in water and plasma samples as well as in bovine milk samples with low and high fat contents. Comparing to the traditional methods, the proposed method exhibits high sensitivity and high preconcentration factors as well as good precision. The extraction setup is simple and due to active transport of analytes, high cleanup effect and good selectivity are obtained in extraction process.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
In this research, for the first time, the QuEChERS was combined with the dispersive liquid–liquid microextraction based on deep eutectic solvent (QuEChERS-DES-DLLME). The method was developed for ...efficient extraction, clean-up and preconcentration of acetamiprid (ACE) and imidacloprid (IMI), two commonly used pesticides, from pistachio samples before their determination by HPLC–UV. The pesticides were firstly extracted from pistachio samples and cleaned-up by QuEChERS, and then their supernatant was used as a dispersant in following DLLME in order to further purification and preconcentration. The extraction solvent used in DLLME was based on deep eutectic solvents (DESs). Preparation of hydrophobic DES was done by mixing amyl alcohol as hydrogen bond donor and trioctylmethylammonium chloride (TOMAC) as hydrogen bond acceptor. Different parameters that affect the efficiency of the two steps were evaluated and optimized. Under optimal conditions, the limit of detections was 1.5 and 3.0 μg kg
−1
for ACE and IMI and the limit of quantification was 1.5 and 4.5 μg kg
−1
for ACE and IMI, respectively. Calibration curves were linear in the range 5.0–500 μg kg
−1
with correlation coefficients higher than 0.99. Preconcentration factor for ACE and IMI was 16 and 13, respectively. The intraday and interday precisions at concentration levels of 10 and 100 μg kg
−1
were less than 7.0%. Finally, applicability of the suggested method was investigated through analysis of the analytes in some pistachio samples, and the obtained relative recoveries (95.6–99.4%) were acceptable. The good sensitivity and suitable purification in the analysis of the pistachio samples, as a complex food matrix, are obtained using the proposed method by combining the advantages of QuEChERS and DLLME.
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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 study, a new and versatile liquid-phase microextraction method is described. This method requires very simple and cheap apparatus and also a small amount of organic solvent. Eight ...microliters of 1-undecanol was delivered to the surface of solution containing analytes and solution was stirred for a desired time. Then sample vial was cooled by inserting it into an ice bath for 5
min. The solidified 1-undecanol was transferred into a suitable vial and immediately melted; then, 2
μL of it was injected into a gas chromatograph for analysis.
Some polycyclic aromatic hydrocarbons (PAHs) were used as model compounds for developing and evaluating of the method performance. Analysis was carried out by gas chromatography/flame ionization detection (GC/FID).
Several factors influencing the microextraction efficiency, such as the nature and volume of organic solvent, the temperature and volume of sample solution, stirring rate and extraction time were investigated and optimized. The applicability of the technique was evaluated by determination of trace amounts of PAHs in environmental samples. Under the optimized conditions, the detection limits (LOD) of the method were in the range of 0.07–1.67
μg
L
−1 and relative standard deviations (R.S.D.) for 10
μg
L
−1 PAHs were <7%. A good linearity (
r
2
>
0.995) in a calibration range of 0.25–300.00
μg
L
−1 was obtained. After 30
min extraction duration, enrichment factors were in the range of 594–1940. Finally, the proposed method was applied to the determination of trace amounts of PAHs in several real water samples, and satisfactory results were resulted. Since very simple devices were used, this new technique is affordable, efficient, and convenient for extraction and determination of low concentrations of PAHs in water samples.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Nalmefene and naltrexone are used to block the effects of narcotics and alcohol. In the present work, for the first time a microextraction technique was presented to reduce matrix interferences and ...improve detection limits of the drugs in urine and plasma samples. Electromembrane extraction (EME) followed by high performance liquid chromatography (HPLC) coupled with ultraviolet (UV) detection was optimized and validated for quantification of nalmefene and naltrexone from biological fluids. The membrane consists 85% of 2-nitrophenyl octyl ether (NPOE) and 15% di-(2-ethylhexyl) phosphate (DEHP) immobilized in the pores of a hollow fiber. A 100
V electrical field was applied to make the analytes migrate from sample solution with pH 2.0, through the supported liquid membrane (SLM) into an acidic acceptor solution with pH 1.0 which was located inside the lumen of hollow fiber. Extraction recoveries in the range of 54% and 75% were obtained in different biological matrices which resulted in preconcentration factors in the range of 109–149 and satisfactory repeatability (2.0
<
RSD%
<
8.3). The method offers good linearity with estimation of coefficient higher than 0.9946. Finally, it was applied to determination and quantification of drugs in human plasma and urine samples and satisfactory results were yielded.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Ultrasonic assistance is one of the great successes of modern analytical chemistry, which uses this energy for a variety of purposes in relation to sample preparation and development of methods for ...the analysis of numerous contaminants including organic and inorganic compounds. This review will attempt to provide an overview of more recent applications of ultrasound in different environmental and biological samples such as food, soil and water as well as a brief description of the theoretical understanding of this method. Also, the possibility of coupling ultrasound with other analytical techniques will be discussed.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
A smartphone-assisted determination of copper ions is introduced by using a down-scaled microfluidic mixer. The system was coupled with a micro-column packed with a periodic mesoporous organosilica ...(PMO) material for preconcentration of copper ions. Copper ions were reduced to Cu(I) on-chip to selectively form an orange-colored complex with neocuproine. A novel Android-based software was made to determine the color change of the adsorbent by analyzing red-green-blue (RGB) components of images from the packed PMO material. Four porous framework materials with high porosity and chemical stability were synthesized and compared for the extraction of the Cu-neocuproine complex. The main parameters influencing the complex extraction efficiency were optimized. The analytical performance of the method showed limit of detection and quantification of 0.2 μg L
−1
and 0.5 μg L
−1
, respectively. The accuracy and precision of the method were determined as recovery > 92% and relative standard deviations < 5.2% at medium concentration level (
n
= 5). Due to accumulation of the retained analyte in a single point and elimination of the stripping step, the RGB-based method showed sensitivity and precision higher than inductively coupled plasma-atomic emission spectrometry (ICP-AES) for determination of copper ions. To investigate the applicability of the method, six different water samples were analyzed. The
t-
test on the data showed that the method has no significant difference when compared with ICP-AES determination.
Graphical Abstract
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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
Copper, as a heavy metal, is toxic for many biological systems. Thus, the determination of trace amounts of copper in environmental samples is of great importance. In the present work, a new method ...was developed for the determination of trace amounts of copper in water samples. The method is based on the formation of ternary Cu(II)–CAS–CTAB ion-pair and adsorption of it into a mini-column packed with cotton prior applying inductively coupled plasma optical emission spectrometry (ICP-OES). The experimental parameters that affected the extraction efficiency of the method such as pH, flow rate and volume of the sample solution, concentration of chromazurol S (CAS) and cethyltrimethylammonium bromide (CTAB) as well as type and concentration of eluent were investigated and optimized. The ion-pair (Cu(II)–CAS–CTAB) was quantitatively retained on the cotton under the optimum conditions, then eluted completely using a solution of 25% (v/v) 1-propanol in 0.5
mol
L
−1 HNO
3 and directly introduced into the nebulizer of the ICP-OES. The detection limit (DL) of the method for copper was 40
ng
L
−1 (
V
sample
=
100
mL) and the relative standard deviation (R.S.D.) for the determination of copper at 10
μg
L
−1 level was found to be 1.3%. The method was successfully applied to determine the trace amounts of copper in tap water, deep well water, seawater and two different mineral waters, and suitable recoveries were obtained (92–106%).
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
In this study, a simple and rapid extraction method based on the application of polypyrrole‐coated Fe3O4 nanoparticles as a magnetic solid‐phase extraction sorbent was successfully developed for the ...extraction and preconcentration of trace amounts of formaldehyde after derivatization with 2,4‐dinitrophenylhydrazine. The analyses were performed by high‐performance liquid chromatography followed by UV detection. Several variables affecting the extraction efficiency of the formaldehyde, i.e., sample pH, amount of sorbent, salt concentration, extraction time and desorption conditions were investigated and optimized. The best working conditions were as follows: sample pH, 5; amount of sorbent, 40 mg; NaCl concentration, 20% w/v; sample volume, 20 mL; extraction time, 12 min; and 100 μL of methanol for desorption of the formaldehyde within 3 min. Under the optimal conditions, the performance of the proposed method was studied in terms of linear dynamic range (10–500 μg/L), correlation coefficient (R2 ≥ 0.998), precision (RSD% ≤ 5.5) and limit of detection (4 μg/L). Finally, the developed method was successfully applied for extraction and determination of formaldehyde in tap, rain and tomato water samples, and satisfactory results were obtained.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
In this work, for the first time, a rapid, simple and sensitive microextraction procedure is demonstrated for the matrix separation, preconcentration and determination of inorganic selenium species ...in water samples using an electrochemically controlled in-tube solid phase microextraction (EC-in-tube SPME) followed by hydride generation atomic absorption spectrometry (HG-AAS). In this approach, in which EC-in-tube SPME and HG-AAS system were combined, the total analysis time, was decreased and the accuracy, repeatability and sensitivity were increased. In addition, to increases extraction efficiency, a novel nanostructured composite coating consisting of polypyrrole (PPy) doped with ethyleneglycol dimethacrylate (EGDMA) was prepared on the inner surface of a stainless-steel tube by a facile electrodeposition method. To evaluate the offered setup and the new PPy-EGDMA coating, it was used to extract inorganic selenium species in water samples. Extraction of inorganic selenium species was carried out by applying a positive potential through the inner surface of coated in-tube under flow conditions. Under the optimized conditions, selenium was detected in amounts as small as 4.0 parts per trillion. The method showed good linearity in the range of 0.012–200 ng mL−1, with coefficients of determination better than 0.9996. The intra- and inter-assay precisions (RSD%, n = 5) were in the range of 2.0–2.5% and 2.7–3.2%, respectively. The validated method was successfully applied for the analysis of inorganic selenium species in some water samples and satisfactory results were obtained.
An electrochemically controlled in-tube solid phase microextraction followed by hydride generation atomic absorption spectrometry was developed for extraction and determination ultra-trace amounts of Se in aqueous solutions. Display omitted
•A nanostructured composite coating consisting of PPy doped with EGDMA was prepared.•The coating was synthesised electrochemically in inner surface of a stainless-steel capillary tube.•It was used to extract Se from water samples followed by hydride generation AAS.•Extraction of selenium was carried out by applying a positive potential into in-tube SPME.•Ultra trace amounts of Se with LOD = 8.0 ppt was detected in aqueous solutions.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
In the present study, extraction of mebendazole across a supported-liquid membrane (SLM) was performed based on two different driving forces: (1) pH gradient over the SLM, and (2) electrical field ...sustained over the SLM. The extracted drug concentration was studied using reversed-phase HPLC–UV. At passive extraction conditions, mebendazole was extracted from alkaline samples (0.01
mmol
L
−1 NaOH) into 1-undecanol immobilized in the pores of a porous hollow fiber of polypropylene (SLM), and then transported into 25
μL of 100
mM HCl as the acceptor solution. Under electrokinetic migration conditions, mebendazole transported under applied voltage from acidic solutions (100
mmol
L
−1 HCl) through 2-nitrophenyl octyl ether (NPOE) immobilized in the pores of hollow fiber, into 25
μL of 100
mmol
L
−1 HCl as the acceptor solution. The effects of several factors including the nature of organic solvent, pH of donor and acceptor solutions, extraction time and stirring speed on the extraction efficiency of the drug were investigated and optimized. Under optimal conditions, preconcentration factors (PF) of 211 and 190 were obtained for the drug based on passive transport and electromembrane extraction (EME), respectively. Also, linear range of 0.5–1000
μg
L
−1 with estimation of coefficient higher than 0.994 was obtained for both of the proposed methods. The results showed that EME has higher speed in comparison with simple passive transport. The methods were successfully applied to extract mebendazole from plasma and urine samples and satisfactory results were obtained.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
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