Use of Chrysosporium/carbon nanotubes for preconcentration of ultra-trace cadmium levels from various samples after extensive studies on its adsorption properties.

Carbon nanotubes were used to immobilize Chrysosporium fungus for building an adequate adsorbent to be used as an desirable sorbent for preconcentration and measurement of cadmium ultra-trace levels in various samples. After characterization, the potential of Chrysosporium/carbon nanotubes for the sorption of Cd(II) ions was scrutinized by the aid of central composite design, and comprehensive studies of sorption equilibrium, kinetics and thermodynamic aspects were accomplished. Then, the composite was utilized for preconcentration of ultra-trace cadmium levels, by a mini-column packed with Chrysosporium/carbon nanotubes, before its determination with ICP-OES. The outcomes vouchsafed that (i) Chrysosporium/carbon nanotube has a high tendency for selective and rapid sorption of cadmium ion, at pH 6.1, and (ii) kinetic, equilibrium, and thermodynamic studies showed a high affinity of the Chrysosporium/carbon nanotubes for cadmium ion. Also, the outcomes displayed that cadmium can quantitatively be sorbed at a flow speed lesser than 7.0 mL/min and a 1.0 M HCl solution (3.0 mL) was sufficient to desorbe the analyte. Eventually, preconcentration and measurement of Cd(II) in different foods and waters were successfully accomplished with good accuracy, high precision (RSDs ≤5.65%), and low limit of detection (0.015 µg/L).

Dietary Modifications in Critically-Ill Patients: A Comparison of Persian Medicine and Conventional Medicine Perspectives.

In Persian Medicine (PM) literature, a crisis is the culmination of the body's response to illness, which necessitates fundamental dietary modification to improve prognosis. In this narrative review, authentic PM textbooks as well as articles on diets for critically-ill patients (CIPs) obtained from PubMed and Google Scholar databases, were reviewed, and after gathering data, they were classified, coded, analyzed, and compared. In the acute phase, both PM and conventional medicine agree on relative food restriction, but PM lays a special focus on the use of meat in cases of weakness. There are both similarities and differences between PM and conventional medicine regarding nutritional recommendations in critical illness. For example, recommendations for food restriction and protein intake are similar in both schools, but recommendations for carbohydrate intake are different. The variables addressed and emphasized in PM require further evaluation in clinical trials.

Polyvinyl alcohol and sodium alginate hydrogel coating with different crosslinking procedures on a PSf support for fabricating high-flux NF membranes.

Polyvinyl alcohol (PVA) and sodium alginate (SA) hydrogel-coated nanofiltration (NF) membranes with high-flux and permselectivity were prepared. The coating of PVA and SA hydrogel selective layer on a porous polysulfone (PSf)/non-woven fabric ultrafiltration substrate membrane was conducted through different three procedures including pre-crosslinking, in-situ crosslinking, and immersing crosslinking and the use of glutaraldehyde as a crosslinking agent. The properties and performances of all types of the prepared membranes were evaluated through ATR-FTIR spectroscopy, AFM, SEM, zeta potential, contact angle, and cross-flow permeation tests. The immersing technique resulted in the formation of TFC membranes with higher hydrophilicity, smoother surface layer, higher negative charge, higher permeation flux, higher salt rejection and better anti-fouling performance. Also, the higher negative surface charge of the immersing coated TFC membranes due to dissociation of hydrophilic functional groups of the PVA and SA hydrogel selective layer resulted in higher As(III) rejection. SA coated NF membrane through immersing method exhibited a higher pure water permeability of 11.2 L m-2 h-1 bar-1, NaCl, MgSO4, and Na2SO4 rejection of 38.2%, 55.1%, and 70.4%, respectively with As(III) rejection of 60.6%. All types of the PVA and SA hydrogel-coated PSf membranes possessed improved fouling resistance to BSA aqueous solution, superior anti-fouling performance was obtained with SA hydrogel coating through immersing method. Such optimum membranes indicated high stability in the long-term experiments. This study showed that the coating of the SA hydrogel layer on a PSf support through immersing method could be a promising candidate for fabricating high-flux NF membranes.

Electrochemical determination of epirubicin in the presence of topotecan as essential anti-cancer compounds using paste electrode amplified with Pt/SWCNT nanocomposite and a deep eutectic solvent.

Epirubicin (EP) and topotecan (TP) are two major anti-cancer compounds for the treatment of breast cancer with serious side effects. Hence herein, a carbon paste electrode (CPE) amplified with Pt/SWCNT nanocomposite and a deep eutectic solvent (CPE/DES/Pt-SWCNT) were proposed as an analytical tool for the monitoring of EP in the presence of TP in the real samples. Amplification of sensor was improve EP oxidation signal about 2.73 times. Under the optimized conditions, EP determined by using differential pulse voltammetry (DPV) technique with linear dynamic range of 0.001-500 µM with limit of detection (LOD) of 0.8 nM. The CPE/DES/Pt-SWCNT offered influential ability for monitoring of EP in injection and dextrose saline samples with a recovery range of 97.4%-104.9%.

Electrochemical Measurement of Noscapine and Lorazepam Using a Carbon Paste Electrode Modified with Multi-walled Carbon Nanotubes and Natural Deep Eutectic Solvent.

In the present study, simultaneous voltammetric determination of noscapine (NOS) and lorazepam (LOR) was studied for the first time. A carbon paste electrode modified with multi-walled carbon nanotubes (MWCNTs) and natural deep eutectic solvent (NANADES) (MWCNTs/NADES/CPE) was used for this purpose. Electrochemical impedance spectroscopy (EIS) was applied for the investigation of the electron transfer rate of [Fe(CN)6]3-/4- as a redox couple probe on the surface of the MWCNTs/NADES/CPE. The modified electrode preserved and combined the properties of the individual modifiers synergistically. A significant enhancement in the peak current responses of NOS and LOR was observed on the modified electrode surface compared to the bare electrode. Under the optimal conditions, the peak current of differential pulse voltammograms was linearly dependent on analyte concentration in the range of 3-1700 µM for NOS and 1-2220 µM for LOR. The limit of detection (LOD) for NOS and LOR was 1.90 µM and 0.69 µM, respectively. Finally, this strategy was also employed for the determination of NOS and LOR in pharmaceutical samples.

Fabrication of chitosan-aminopropylsilane graphene oxide nanocomposite hydrogel embedded PES membrane for improved filtration performance and lead separation.

In the present study chitosan-aminopropylsilane graphene oxide (CS-APSGO) nanocomposite hydrogel was synthesized and utilized as a hydrophilic additive in different dosages (0.5, 1, 2 and 5 wt%) in fabrication of porous polyethersulfone (PES) membranes via the phase inversion induced process by immersion precipitation method for heavy metal ion and dye removal. The modified membranes were characterized using ATR-FTIR, AFM, SEM, water contact angle, overall porosity and mean pore radius evaluations and zeta potential measurement. The addition of CS-APSGO nanocomposite hydrogel to PES doping solutions enhanced membranes hydrophilicity and consequently pure water flux permeability. Filtration performance of the CS-APSGO embedded membranes showed promising antifouling properties during BSA filtration test (FRR> 90%) and 1 wt% membranes showed the highest pure water flux of 123.8 L/m2 h with BSA rejection more than 98% and removal capability more than 82% for lead (II) ion, 90.5% and 98.5% for C.I. Reactive Blue 50 and C.I. Reactive Green 19, respectively. Therefore, the CS-APSGO nanocomposite hydrogel blending in order to modification of PES-based membranes have a noticeable potential in improving filtration performance of blended membranes.

Highly effective and safe intermediate based on deep eutectic medium for carrier less-three phase hollow fiber microextraction of antiarrhythmic agents in complex matrices.

For the first time, three phase hollow fiber liquid phase microextraction using an influential, and green middle phase comprised a new relatively-hydrophobic deep eutectic solvent (three-phase HF-LPME-DES) was developed for trace analyses of antiarrhythmic drugs in biological and environmental samples. The extraction solvent was easily synthesized by mixing the green and cheap raw materials, namely choline chloride and 1-phenylethanol (ChCl: Ph-ETOH), in the ambient temperature. Good compatibility to pores of hollow-fiber, high ability for extraction of ionizable organic compounds with no need to any carrier agents, and easy availability in the laboratory environment turned this new proposed deep eutectic intermediate to a worthy generation of the supported liquid membrane (SLM). Final determination was accurately done by high performance liquid chromatography-ultraviolet detection (HPLC-UV). After effective statistical optimization of main parameters, the valid analytical features were found to be: wide linear dynamic ranges (LDRs) of 0.8 to 500 ng mL-1 with the determination coefficients (R2s) higher than 0.98, low detection limits (LODs) of 0.3-0.8 ng mL-1, and logical precision (relative standard deviations (%RSDs, n = 3) of 5.2-6.5%). Also, enrichment factors and extraction recoveries were 110-135 and 44-54%, respectively. These satisfactory results confirmed the potent effectiveness of the proposed microextraction procedure for achievement to clean and proper enrichment of the aforesaid compounds in highly complex real samples.

Determination of acidic drugs in biological and environmental matrices by membrane-based dual emulsification liquid-phase microextraction followed by high-performance liquid chromatography.

A simple method is introduced providing a highly clean microextraction for the determination of some anti-inflammatory drugs as the model analytes in human urine and environmental matrices. This method is based upon the implementation of two consecutive emulsification liquid-phase microextractions, which are separated by a syringe filtration step. In this method, the organic extraction solvent (dihexyl ether) is dispersed into the aqueous sample solution (20 mL), and the resulting cloudy mixture is passed through a hydrophilic polytetrafluoroethylene syringe filter. By this action, the extraction phase containing the analytes and many interfering species that could be transferred into the organic phase is retained behind the hydrophilic membrane. The filter is then detached from the syringe and attached to another syringe containing an aqueous solution (pH 12.0, 150 µL), and by the in-syringe dispersion of the organic phase into the aqueous phase, the analytes are selectively back-extracted into the aqueous phase. The developed method is centrifuge-free and very simple, and provides a high sample clean-up in a few minutes. Under the optimized experimental conditions, the developed method provided a linearity in the range of 2.0-2000 ng/mL, a low limit of detection (0.5 ng/mL), and enrichment factors of 47-53.

Emulsification microextraction of amphetamine and methamphetamine in complex matrices using an up-to-date generation of eco-friendly and relatively hydrophobic deep eutectic solvent.

In this study, a new extraction medium based on a quite bio-compatible and bio-degradable deep eutectic solvent comprising choline chloride and phenylethanol (ChCl: Ph-ETOH) was simply and cheaply synthesized at room temperature. At the next step, it was effectively utilized at the service of air agitated-emulsification microextraction (AA-EME) of two major amphetamine-type stimulants (ATSs) in human plasma and pharmaceutical wastewater pursued by high performance liquid chromatography-ultraviolet detection (HPLC-UV). This safe, effective, and rapid enrichment process based on the new low-density DES was easily practicable via a homemade extraction cell possessing a narrow neck and with no extra demand the emulsifier intermediates. Statistical study of main parameters effects using central composite design (CCD) combined with desirability function (DF) demonstrated that pH 12, 250 µL of extraction solvent, 8 air agitation cycles, and 5% of salt amount resulted in maximum extraction efficiencies (63-66%) with DF value close to 0.98. Under optimal conditions, wide linear dynamic ranges (LDRs) of 15.0-2000 and 8.0-3000 ng mL-1 with the determination coefficients (R2s) close to 0.99 were obtainable for amphetamine and methamphetamine, respectively. Low limits of detection (LODs) as well as relative standard deviations (%RSDs, n = 3) were found to be 2.0-5.0 ng mL-1 and 5.7-7.8%, respectively. Also, enrichment factors (EFs) were quantitative in the span of 47-50. On the other hand, satisfactory and accurate assessment at low levels close to therapeutic and toxic domains in human plasma sample and pharmaceutical wastewater was successfully obtained.

Filter-based emulsification microextraction as an efficient method for the determination of chlorophenols by gas chromatography.

In this work, an efficient microextraction method was applied for the extraction of some chlorophenols in water samples. This method, termed filter-based emulsification microextraction, is based on the dispersion of an extractant into an aqueous sample solution to accelerate the extraction process and the utilization of a Nylon syringe filter to break the emulsion. After phase separation, the method is coupled with gas chromatography as a final analyzer instrument. The overall derivatization/extraction time was about 90 s. The proposed method is centrifuge-free, and it also provides a suitable sample clean-up by filtration of the extracting phase. The effective parameters involved in the extraction method were optimized. Under the optimal experimental conditions, the method provided a good linearity in the range of 2.0-2000 ng/mL, extraction repeatabilities (relative standard deviations) below 9.4%, enrichment factors of 180-203, and limits of detection between 0.5 and 1.2 ng/mL.

Magnetic nanoparticle based solid-phase extraction of heavy metal ions: A review on recent advances.

This review (with 151 refs) focuses on recent progress that has been made in magnetic nanoparticle-based solid phase extraction (SPE), pre-concentration and speciation of heavy metal ions. In addition, it discusses applications to complex real samples such as environmental, food, and biological matrices. The introduction addresses current obstacles and limitations associated with established SPE approaches and discusses the present state of the art in different formats of off-line and on-line SPE. The next section covers magnetized inorganic nanomaterials for use in SPE, with subsections on magnetic silica, magnetic alumina and titania, and on magnetic layered double oxides. A further section treats magnetized carbonaceous nanomaterials for use in SPE, with subsections on magnetic graphene and/or graphene oxides, magnetic carbon nanotubes and magnetic carbon nitrides. We then discuss the progress made in SPE based on the use of magnetized organic polymers (mainly non-imprinted and ion-imprinted polymer). This is followed by shorter sections on the use of magnetized metal organic frameworks, magnetized ionic liquids and magnetized biosorbents. All sections include discussions of the nanomaterials in terms of selectivity, sorption capacity, mechanisms of sorption and common routes for material synthesis. A concluding section addresses actual challenges and discusses perspective routes towards further improvements. Graphical abstract An overview on booster nanomaterials (ionic liquids, inorganic, organic and biological materials, and metal-organic frameworks) for use in magnetic nanoparticle-based solid-phase extraction of heavy metal ions.

Simple determination of some antidementia drugs in wastewater and human plasma samples by tandem dispersive liquid-liquid microextraction followed by high-performance liquid chromatography.

In this work, a simple method, namely, tandem dispersive liquid-liquid microextraction, with a high sample clean-up is applied for the rapid determination of the antidementia drugs rivastigmine and donepezil in wastewater and human plasma samples. This method, which is based on two consecutive dispersive microextractions, is performed in 7 min. In the method, using a fast back-extraction step, the applicability of the dispersive microextraction methods in complicated matrixes is conveniently improved. This step can be performed in less than 2 min, and very simple tools are required for this purpose. To achieve the best extraction efficiency, optimization of the variables affecting the method was carried out. Under the optimized experimental conditions, the relative standard deviations for the method were in the range of 6.9-8.7%. The calibration curves were obtained in the range of 2-1100 ng/mL with good correlation coefficients, higher than 0.995, and the limits of detection ranged between 0.5 and 1.0 ng/mL.

Centrifugeless dispersive liquid-liquid microextraction based on salting-out phenomenon followed by high performance liquid chromatography for determination of Sudan dyes in different species.

In this work, a novel method, namely centrifugeless dispersive liquid-liquid microextraction, is introduced for the efficient extraction of banned Sudan dyes from foodstuff and water samples. In this method, which is based upon the salting-out phenomenon, in order to accelerate the extraction process, the extraction solvent (1-undecanol, 75 µL) is dispersed into the sample solution. Then the mixture is passed through a small column filled with 5 g sodium chloride, used as a separating reagent. In this condition, fine droplets of the extraction solvent are floated on the mixture, and the phase separation is simply achieved. This method is environmentally friendly, simple, and very fast, so that the overall extraction time is only 7 min. Under the optimal experimental conditions, the preconcentration factors in the range of 90-121 were obtained for the analytes. Also good linearities were obtained in the range of 2.5-1200 ng mL-1 (r2 ≥ 0.993).

Efficient and relatively safe emulsification microextraction using a deep eutectic solvent for influential enrichment of trace main anti-depressant drugs from complicated samples.

In this research work, an efficient, facile, prompt, and relatively safe enrichment procedure, named as air agitated-emulsification microextraction based on a low density-deep eutectic solvent (AA-EME-LD-DES), was applied for the first time to separate trace amounts of the drugs escitalopram, desipramine, and imipramine from complex sample solutions. This bio-degradable and cheap choline chloride-based extracting agent was readily prepared by the easy blending process at the ambient temperature, resulting in a eutectic liquid mixture with distinct features. Also the subsequent usage of an effective proceeding of the current microextraction procedure without a vital requirement for a further purification was adopted as another impressive benefit. Investigation of the main parameters influencing the multivariate technique based on the central composite design (CCD) combined with the desirability function (DF) revealed that pH12.0, 200µL of the extraction solvent, 430µL of the emulsifier solvent, and 14 air agitation cycles led to maximum extraction efficiencies with the DF value close to 0.97. Under the optimal experimental conditions, the wide linear dynamic ranges (LDRs) of 10.0-5000, 15.0-8000, and 15.0-6000ngmL-1 for escitalopram, desipramine, and imipramine were accurately obtainable, respectively, with the determination coefficients (R2s) higher than 0.98 and the low limits of detection (LODs) of 3.0-4.5ngmL-1. The percent extraction recoveries and enrichment factors were found to be adequately quantitative in the spans of 42-68% and 25-40, respectively, possessing good relative standard deviations (%RSDs, n=3) in the range of 3.6-5.7%. Finally, accurate analyses at therapeutically low ranges for the human plasma sample and trace levels for the pharmaceutical wastewater sample were successfully obtained, certifying the appropriate pre-concentration and enrichment capabilities of the proposed microextraction approach.

Coupling of two centrifugeless ultrasound-assisted dispersive solid/liquid phase microextractions as a highly selective, clean, and efficient method for determination of ultra-trace amounts of non-steroidal anti-inflammatory drugs in complicated matrices.

In this work, a new, simple, rapid, and environmentally friendly method with a high sample clean-up capability termed as centrifugeless ultrasound-assisted dispersive micro solid-phase extraction coupled with salting-out ultrasound-assisted liquid-liquid microextraction based on solidification of a floating organic droplet followed by high performance liquid chromatography is introduced for the first time. In this method, the three non-steroidal anti-inflammatory drugs diclofenac, ibuprofen, and mefenamic acid are first extracted based on an effective nanoadsorbent named as the layered double hydroxide-carbon nanotube nanohybrid. The first step provides a rapid and convenient way to separate the adsorbent from the sample matrix by a syringe nanofilter without additional centrifugation. In the next step, which is based upon the salting-out effect, after emulsification in the presence of ultrasonic irradiation, the phase separation is simply achieved through the salting-out phenomenon, and the extracting solvent is suspended on top of the sample solution. Under the optimal experimental conditions including the initial pH value of 6.0, 8.0 mg of the nanohybrid, 3 min ultrasonic time, 100 µL elution solvent (first step), secondary pH value of 3.0, 60 µL of 1-undecanol, 60 s ultrasonic time, and flow rate of 3 mL min-1 (second step), good responses were obtained for diclofenac, ibuprofen, and mefenamic acid in the concentration ranges of 0.8-2000, 0.8-2500, and 0.5-2000 ng mL-1, respectively, with low limits of detection ranging from 0.1 to 0.2 ng mL-1. The intra-day and inter-day precisions for the target analytes at the three concentration levels were in the ranges of 6.1-7.8% and 6.3-8.1%, respectively. The proposed method was also successfully applied to the biological and waste water samples, and excellent recoveries were obtained in the range of 92.9-103.1% even when the matrix was complex.

A twin purification/enrichment procedure based on two versatile solid/liquid extracting agents for efficient uptake of ultra-trace levels of lorazepam and clonazepam from complex bio-matrices.

In this research work, two consecutive dispersive solid/liquid phase microextractions based on efficient extraction media were developed for the influential and clean pre-concentration of clonazepam and lorazepam from complicated bio-samples. The magnetism nature of the proposed nanoadsorbent proceeded the clean-up step conveniently and swiftly (∼5min), pursued by a further enrichment via a highly effective and rapid emulsification microextraction process (∼4min) based on a deep eutectic solvent (DES). Finally, the instrumental analysis step was practicable via high performance liquid chromatography-ultraviolet detection. The solid phase used was an adequate magnetic nanocomposite termed as polythiophene-sodium dodecyl benzene sulfonate/iron oxide (PTh-DBSNa/Fe3O4), easily and cost-effectively prepared by the impressive co-precipitation method followed by the efficient in situ sonochemical oxidative polymerization approach. The identification techniques viz. FESEM, XRD, and EDX certified the supreme physico-chemical properties of this effective nanosorbent. Also the powerful liquid extraction agent, DES, based on bio-degradable choline chloride, possessed a high efficiency, tolerable safety, low cost, and facile and mild synthesis route. The parameters involved in this versatile hyphenated procedure, efficiently evaluated via the central composite design (CCD), showed that the best extraction conditions consisted of an initial pH value of 7.2, 17mg of the PTh-DBSNa/Fe3O4 nanocomposite, 20 air-agitation cycles (first step), 245µL of methanol, 250µL of DES, 440µL of THF, and 8 air-agitation cycles (second step). Under the optimal conditions, the understudied drugs could be accurately determined in the wide linear dynamic ranges (LDRs) of 4.0-3000ngmL-1 and 2.0-2000ngmL-1 for clonazepam and lorazepam, respectively, with low limits of detection (LODs) ranged from 0.7 to 1.0ngmL-1. The enrichment factor (EF) and percentage extraction recovery (%ER) values were found to be 75 and 57% for clonazepam and 56 and 42% for lorazepam at the spiked level of 75.0ngmL-1, possessing proper repeatabilities (relative standard deviation values (RSDs) below 5.9%, n=3). These valid analytical features provided quite accurate drug analyses at therapeutically low spans and levels below potentially toxic domains, implying a proper purification/enrichment of the proposed microextraction procedure.

Ultrasound-promoted dispersive micro solid-phase extraction of trace anti-hypertensive drugs from biological matrices using a sonochemically synthesized conductive polymer nanocomposite.

In this work, a rapid and efficient procedure named ultrasound meliorated dispersive micro solid-phase extraction followed by high performance liquid chromatography-ultra violet detection (US-D-µSPE-HPLC-UV) was developed for the pre-concentration of the main trace anti-hypertensive drugs in complex matrices. The basis of this procedure was a polypyrrole-sodium dodecylbenzenesulfonate/zinc oxide (PPy-DBSNa/ZnO) nanocomposite. It was readily synthesized by the impressive way of in situ sonochemical oxidative polymerization in the presence of some additives such as FeCl3 and DBSNa, ultimately leading to the effective coating of PPy on the ZnO nanoparticle cores. Characterization of the proposed nanosorbent was performed by different techniques such as FESEM, XRD,EDX, and TGA, confirming the high quality and proper physico-chemical properties of the proposed sorbent. In order to better investigate the input variables, the central composite design (CCD) combined with the desirability function (DF) was utilized. The enriched optimum conditions consisted of the initial pH value of 11.8, 15mg of the PPy-DBSNa/ZnO nanocomposite, a sonication time of 4.6min, and 100µL of methanol, resulting in maximum responses at a relatively low extraction time with a logical DF. Under the optimum conditions, good linearity (5-5000, 2.5-3500, and 2.5-3000ngmL-1 for metoprolol, propranolol, and carvedilol, respectively, with the correlation of determinations (R2s) higher than 0.99), low limits of detection (LODs) (0.8-1.5ngmL-1), proper repeatabilities (relative standard deviation values (RSDs) below 6.3%, n=3), reasonable enrichment factors (EFs) (60-72), and good extraction recoveries (ERs) (higher than %75) were obtainable. These appropriate validations corroborated a good effectiveness of ultrasonic waves in the achievement of a supreme solid phase as well as a facile and efficient microextraction of the low therapeutic concentrations in human plasma and urine samples.

Improved in-tube electro-membrane extraction followed by high-performance liquid chromatography for simple and selective determination of ionic compounds: Optimization by central composite design.

In this work, an efficient sample clean-up method, named in-tube electro-membrane extraction, is modified to resolve the formation of bubbles in the extraction process. This modified method is applied for the extraction of two model analytes including tartrazine and sunset yellow from food samples. The method is based on the electro-kinetic migration of ionized compounds by the application of an electrical potential difference, and on this basis the analytes under investigation, as anionic compounds, simply migrate from the donor phase and concentrate in the acceptor phase. A thin polypropylene sheet placed in the tube acts as a support for the membrane solvent, and it separates 30 µL of the aqueous acceptor from 1.2 mL of the aqueous donor. This setup can be used to solve the problem of extracting highly hydrophilic analytes. Response surface methodology is used for optimization of the experimental parameters so that under the optimized conditions, the method provides a good linearity in the range of 50-1000 ng/mL, low limits of detection (15-25 ng/mL), good extraction repeatabilities (relative standard deviations below 8.1%, n = 5), and high extraction recoveries (54-76%).

Combination of magnetic dispersive micro solid-phase extraction and supramolecular solvent-based microextraction followed by high-performance liquid chromatography for determination of trace amounts of cholesterol-lowering drugs in complicated matrices.

A novel, efficient, rapid, simple, sensitive, selective, and environmentally friendly method termed magnetic dispersive micro solid-phase extraction combined with supramolecular solvent-based microextraction (Mdµ-SPE-SSME) followed by high-performance liquid chromatography (HPLC) with UV detection is introduced for the simultaneous microextraction of cholesterol-lowering drugs in complicated matrices. In the first microextraction procedure, using layered double hydroxide (LDH)-coated Fe3O4 magnetic nanoparticles, an efficient sample cleanup is simply and rapidly provided without the need for time-consuming centrifugation and elution steps. In the first step, desorption of the target analytes is easily performed through dissolution of the LDH-coated magnetic nanoparticles containing the target analytes in an acidic solution. In the next step, an emulsification microextraction method based on a supramolecular solvent is used for excellent preconcentration, ultimately resulting in an appropriate determination of the target analytes in real samples. Under the optimal experimental conditions, the Mdµ-SPE-SSME-HPLC-UV detection procedure provides good linearity in the ranges of 1.0-1500 ng mL-1, 1.5-2000 ng mL-1, and 2.0-2000 ng mL-1 with coefficients of determination of 0.995 or less, low limits of detection (0.3, 0.5, and 0.5 ng mL-1), and good extraction repeatabilities (relative standard deviations below 7.8%, n = 5) in deionized water for rosuvastatin, atorvastatin, and gemfibrozil, respectively. Finally, the proposed method is successfully applied for the determination of the target analytes in complicated matrices. Graphical Abstract Mdµ-SPE-SSME procedure.

Rapid determination of some psychotropic drugs in complex matrices by tandem dispersive liquid-liquid microextraction followed by high performance liquid chromatography.

Simple and rapid determinations of some psychotropic drugs in some pharmaceutical wastewater and human plasma samples were successfully accomplished via the tandem dispersive liquid-liquid microextraction combined with high performance liquid chromatography-ultraviolet detection (TDLLME-HPLC-UV). TDLLME of the three psychotropic drugs clozapine, chlorpromazine, and thioridazine was easily performed through two consecutive dispersive liquid-liquid microextractions. By performing this convenient method, proper sample preconcentrations and clean-ups were achieved in just about 7min. In order to achieve the best extraction efficiency, the effective parameters involved were optimized. The optimal experimental conditions consisted of 100µL of CCl4 (as the extraction organic solvent), and the pH values of 13 and 2 for the donor and acceptor phases, respectively. Under these optimum experimental conditions, the proposed TDLLME-HPLC-UV technique provided a good linearity in the range of 5-3000ngmL-1 for the three psychotropic drugs with the correlation of determinations (R2s) higher than 0.996. The limits of quantification (LOQs) and limits of detection (LODs) obtained were 5.0ngmL-1 and 1.0-1.5ngmL-1, respectively. Also the proper enrichment factors (EFs) of 96, 99, and 88 for clozapine, chlorpromazine, and thioridazine, respectively, and good extraction repeatabilities (relative standard deviations below 9.3%, n=5) were obtained.