Trace-level monitoring of anti-cancer drug residues in wastewater and biological samples by thin-film solid-phase micro-extraction using electrospun polyfam/Co-MOF-74 composite nanofibers prior to liquid chromatography analysis.

Sample preparation methods with high accuracy and matrix resistance will benefit the quick analysis of desired analytes in an intricate matrix, such as the monitoring of drug samples in biofluids. Herein, an electrospun composite, consisting of polyfam and a Co-metal organic framework- 74, was developed as a novel sorbent for the high-throughput solid-phase micro-extraction of certain anti-cancer drugs (sorafenib, dasatinib, and erlotinib hydrochloride) from wastewater and biological samples before high-performance liquid chromatography- ultraviolet analysis (HPLC-UV). The synthesis of the resulting composite nanofibers was confirmed using the techniques of Fourier transform-infrared spectroscopy, field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDX), and powder X-ray diffraction (XRD). FESEM images illustrated irregular and bead-free nanofibers with a diameter range of 126.9-269.6 nm. Thanks to the incorporation of Co-MOF-74 into the polyfam network, the electrospun nanofibers displayed a large surface area, high porosity, and significant extraction efficiency toward target analytes. Under optimal experimental conditions, the linearity was achieved in the range of 0.1-1500.0 µg L-1 for sorafenib and 0.5-1500.0 µg L-1 for dasatinib and erlotinib hydrochloride, with a coefficient of determination of ≥0.9996. The detection limits (LODs) were calculated within the range of 0.03-0.20 µg L-1. The relative standard deviation values (RSDs %) were in the range of 3.1%-8.6% (intra-day, n = 6) and 7.0%-10.3% (inter-day, n=3) in the span of three days. Ultimately, the application of the developed method was appraised for the quantification of trace amounts of the intended analytes in various spiked samples.

Application of electrospun polyacrylonitrile/Zn-MOF-74@GO nanocomposite as the sorbent for online micro solid-phase extraction of chlorobenzenes in water, soil, and food samples prior to liquid chromatography analysis.

An online micro solid-phase extraction (online-µSPE) using electrospun nanofibers, as an efficient sorbent, was developed to extract chlorobenzenes (CBs) from paddy soil, agricultural wastewater, and food samples (fruit juices, vegetables, rice samples) followed by high performance liquid chromatography analysis. Electrospun nanofibers were fabricated using a nanocomposite containing polyacrylonitrile and Zn-metal organic framework 74 @graphene oxide (PAN/Zn-MOF-74@GO), and subsequently characterized. Under the optimal conditions, acceptable linearity was obtained in the range of 0.25-700.00 ng mL-1 for 1,2-dichlorobenzene (1,2-DCB) and 2.50-700.00 ng mL-1 for both 1,2,3-trichlorobenzene (1,2,3-TCB) and 1,2,4-trichlorobenzene (1,2,4-TCB) with determination coefficients ≥ 0.9991. The limits of detection ranged from 0.08 to 1.10 ng mL-1. The intra-day and inter-day single fiber and fiber to fiber relative standard deviations were observed in the range of 4.1%-9.5% and 5.8%-12.1%, respectively. The performance of this method was examined by determining the target analytes in the different spiked samples.

Preparation of Polyacrylonitrile/Ni-MOF electrospun nanofiber as an efficient fiber coating material for headspace solid-phase microextraction of diazinon and chlorpyrifos followed by CD-IMS analysis.

Herein, an electrospun polyacrylonitrile/nickel-based metal-organic framework nanocomposite (PAN/Ni-MOF) coating on a stainless steel wire was synthesized and employed as a novel nanosorbent for headspace solid-phase microextraction (HS-SPME) of organophosphorus pesticides (OPPs), diazinon (DIZ), and chlorpyrifos (CPS) from the diverse aqueous media followed by corona discharge ion mobility spectrometry (CD-IMS). Under the optimum experimental conditions, the calibration plots were linear in the range of 1.0-250.0 ng mL-1 for DIZ and 0.5-300.0 ng mL-1 for CPS with r2 > 0.999. The detection limits (S/N = 3) were 0.3 and 0.2 ng mL-1 for DIZ and CPS, respectively. The intra-day relative standard deviations (RSDs%) (n = 5) at the concentration levels of 20.0, 40.0, and 100.0 ng mL-1 were ≤ 5.2%. To investigate the extraction efficiency, PAN/Ni-MOF was employed to analyze various juice samples, including orange, apple, and grape juices, and in three water samples where it led to good recoveries ranged between 87% and 98%.

Preparation of electrospun polyacrylonitrile/Ni-MOF-74 nanofibers for extraction of atenolol and captopril prior to HPLC-DAD.

Electrospun nanofibers of polyacrylonitrile/Ni-metal-organic framework 74 (PAN/Ni-MOF-74) were prepared and utilized as a novel sorbent for spin-column micro-solid-phase extraction (SC-µSPE) of atenolol (ATN) and captopril (CAP). The electrospun nanofibers were characterized by field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, and X-ray diffraction analysis. Ni-MOF-74 nanoparticles in the polymeric network of polyacrylonitrile considerably enhance the extraction efficiency of the electrospun sorbent due to providing hydrophobic, hydrogen bonding, and π-π interactions with the target analytes. The entire procedure, including sample loading, washing, and eluting of the target analytes was performed by centrifugation of the spin column. The extracted analytes were then quantified by high-performance liquid chromatography with a diode array detector. Various parameters affecting extraction efficiency were optimized using the one-variable-at-a-time method. Under optimum conditions, the calibration plots were linear in the range 0.5-500 ng mL-1 for ATN and 0.3-500 ng mL-1 for CAP with r2 > 0.999. Limits of detection of 0.15 and 0.13 ng mL-1 were obtained for ATN and CAP, respectively. The intra-assay relative standard deviation for five replicate measurements was ≤ 7.8. The relative recoveries for both drugs were within the range 82.6-98.9%. The applicability of the method was successfully investigated for measuring the target drugs in biological fluids and wastewater. The results indicate proper accuracy and analytical performance of the proposed method. Graphical abstract Schematic presentation of electrospun nanofibers of polyacrylonitrile/Ni-metal-organic framework 74 (PAN/Ni-MOF-74) which are used as the sorbent for spin-column microextraction (SC-µSPE) of atenolol (ATN) and captopril (CAP) prior to HPLC-DAD analysis.

Polyacrylonitrile/MIL-53(Fe) electrospun nanofiber for pipette-tip micro solid phase extraction of nitrazepam and oxazepam followed by HPLC analysis.

Nanofibers were prepared from a nanocomposite consisting of polyacrylonitrile and a metal-organic framework of type MIL-53(Fe) by electrospinning. They are shown to be a viable sorbent for pipette-tip solid-phase extraction for the extraction of the benzodiazepine drugs nitrazepam and oxazepam. The nanofibers were characterized by scanning electron microscopy, energy dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy and X-ray diffraction. The effects of sample pH value and volume, composition, and amount of electrospun nanofibers, the number of adsorption cycles and the type and volume of the eluent were optimized. Following extraction the drugs were quantified by HPLC. Under the optimized conditions, response is linear for both drugs in the 5.0-1000 ng mL-1 concentration range. The limits of detection for oxazepam and nitrazepam are 1.5 and 2.5 ng mL-1, respectively, and the relative standard deviations at the levels of 50, 100 and 250 ng mL-1 (for n = 3) are ≤7.6%. The method was successfully applied for determination of drugs in spiked wastewater and biological fluids. Graphical abstractSchematic representation of polyacrylonitrile/MIL-53(Fe) composite nanofiber synthesis by electrospinning, and the use of them as the sorbent in pipette-tip microsolid-phase extraction (PT-µSPE) for the preconcentration of Nitrazepam and Oxazepam before HPLC-DAD analysis.

A nanosized magnetic metal-organic framework of type MIL-53(Fe) as an efficient sorbent for coextraction of phenols and anilines prior to their quantitation by HPLC.

The authors describe the synthesis of a magnetic metal-organic framework (MOF) of type MIL-53(Fe) for coextraction of phenols and anilines from various environmental samples. A quick method for dispersive micro-solid phase extraction (D-µ-SPE) was developed for coextraction of the analytes 4-nitrophenol (4-NP), 4-chlorophenol (4-CP), 4-chloroaniline (4-CA), 1-amino-2-naphtol (1-A2N) and 2, 4-dichloroaniline (2, 4-DCA). The MOF was characterized by SEM, TEM, FT-IR, EDS, thermogravimetry, VSM and XRD. The method was optimized by response surface methodology combined with desirability function approach, specifically with respect to pH value of the sample, amount of sorbent, sorption time, salt concentration, sample volume, type and volume of the eluent, and elution time. Following elution with acetonitrile, the analytes were quantified by HPLC with photodiode array detection. Responses are linear in 0.1-2000 µg·L-1 concentration ranges. The limits of detection and relative standard deviations (for n = 5) are in the range of 0.03-0.2 µg·L-1 and 3.5-12.6%, respectively. Enrichment factors are 113, 61, 87, 144 and 114 for 4-NP, 4-CP, 4-CA, 1-A2N and 2,4-DCA, respectively. Recoveries from spiked samples ranged from 39.5 to 93.3%. The magnetic sorbent was successfully applied to the coextraction and determination of the analytes in river, rain and hookah water samples. Graphical abstract Schematic presentation for the synthesis of (a) Fe3O4 nanoparticles (NPs) and (b) Fe3O4@MIL-53(Fe). Fe3O4@MIL-53(Fe) was employed as a new nanosorbent in dispersive micro-solid phase extraction of phenols and anilines. The limits of detection are in the range of 0.03-0.2 µg·L-1.

Preparation of magnetite/multiwalled carbon nanotubes/metal-organic framework composite for dispersive magnetic micro solid phase extraction of parabens and phthalate esters from water samples and various types of cream for their determination with liquid chromatography.

In the current study, MMWCNTs@MIL-101(Cr) (Fe3O4/multiwalled carbon nanotubes/MIL-101(Cr)) was synthesized and utilized as a new sorbent for the first time. It was employed successfully for the extraction of parabens and phthalate esters (PEs) from water and cream samples prior to their quantification with HPLC-DAD. The prepared metal-organic-framework (MOF) was characterized by field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FT-IR), energy-dispersive X-ray spectroscopy (EDX), EDX mapping, thermogravimetric analysis (TGA), vibrating-sample magnetometer (VSM) and X-ray powder diffraction (XRD). Three phthalate esters (dimethyl phthalate (DMP), diethyl phthalate (DEP), diallyl phthalate (DAP)) and two parabens (methylparaben (MP) and butylparaben (BP)) were chosen as model analytes. Several experimental factors affecting the extraction efficiency, including pH value, nanosorbent amount, sorption time, salt concentration, sample volume, type and volume of the eluent, and elution time were investigated. The optimization of the extraction method was carried out by response surface methodology (RSM) and desirability function (DF) approach. Under the opted conditions, the method was linear in the range of 0.1-1500 µg L-1 with coefficients of determination > 0.9991. The limits of detection of PEs and parabens were found in the range of 0.03-0.15 µg L-1 (S/N = 3). The relative standard deviations were less than 7.5% and the extraction recoveries ranged from 38.04 to 70.62%. The present method was simple, rapid, inexpensive and environmentally friendly and was successfully utilized for the determination of PEs and parabens in water samples and various types of cream samples with satisfactory results.

Dispersive micro-solid phase extraction of aromatic amines based on an efficient sorbent made from poly(1,8-diaminonaphtalen) and magnetic multiwalled carbon nanotubes composite.

In this work, the extraction of aromatic amines with an efficient magnetic multiwalled carbon nanotubes/Fe3O4@Poly(1,8-diaminonaphtalen) (MWCNTs/Fe3O4@PDAN) composite followed by HPLC-DAD was presented. Imprimis, the comparison among different magnetic nanosorbents including Fe3O4, MWCNTs/Fe3O4, Fe3O4@PDAN and MWCNTs/Fe3O4@PDAN was conducted. The obtained results, exhibited that the MWCNTs/Fe3O4@PDAN composite has the highest extraction efficiency for target analytes (3-nitroaniline, 4-chloroaniline, 4-bromoaniline and 3,4-dichloroaniline). This sorbent was characterized by Fourier transform infrared spectroscopy, X-ray dispersive spectroscopy, thermogravimetry analysis, scanning electron microscopy, transition electron microscopy, vibrating sample magnetometry and X-ray diffraction. Design of experiment approach was applied to find out the optimal experimental conditions. The optimal extraction conditions were: pH of the sample, 10; sorbent amount, 10mg; sorption time, 15min; salt concentration, 10% w/w; type and volume of the eluent, 0.01molL-1 HCl in acetonitrile, 145µL; elution time; 2min. Under the optimal extraction conditions detection limits and linear dynamic ranges were achieved in the range of 0.1-0.25µgL-1 and 0.25-500µgL-1, respectively. The percent of extraction recovery and relative standard deviations (n=5) were in the range of 31.2-82.8% and 3.4-5.6%, respectively. Finally, the applicability of the method was successfully confirmed by the extraction and determination of target analytes in various water samples.

A Simple and Fast Method Based on New Magnetic Ion Imprinted Polymer as a Highly Selective Sorbent for Preconcentration and Determination of Cadmium in Environmental Samples.

BACKGROUND: The analysis of heavy metals at trace level is one of the main toxicologists concern, due to their vital rules in human`s life. Cadmium is one of these toxic heavy metals, which released to the environment from various industries. METHODS: In order to determine Cd (II) ions in various matrices magnetic ion-imprinted polymer (IIP) method has been developed and applied. This nano-sorbent has been synthesized by coating an IIP compound on Fe3O4 nanoparticles core to achieve highest surface area. This polymer has been used to evaluate Cd (II) levels in food, river, and wastewater in Tehran, Iran. RESULTS: Fe3O4@Cd-IIP was stable up to 300 °C. The various factors such as sample pH (optimized as 7), elution/sorption time (5 min), eluent amount (4 mL HCL), and its concentration (2 mol L-1) were optimized. Analysis instrument in all steps was Flame Atomic Abortion Spectrophotometer (FAAS). In this study, the detection limit was determined down to 0.6 µg L-1. CONCLUSION: This method was applied successfully for the preconcentration and determination of Cd (II) ions in environmental samples obtained from rivers, various foods and wastewater. In addition, the accuracy of the method was confirmed by analyzing a certified reference material (Seronorm LOT NO2525) and spiked real samples.

Surfactant-assisted dispersive liquid-liquid microextraction of nitrazepam and lorazepam from plasma and urine samples followed by high-performance liquid chromatography with UV analysis.

Surfactant-assisted liquid-liquid microextraction followed by high-performance liquid chromatography with UV detection has been developed for the simultaneous preconcentration and determination of lorazepam and nitrazepam in biological fluids. In this study, an ionic surfactant (cetyltrimethyl ammonium bromide) was used as an emulsifier. The predominant parameters affecting extraction efficiency such as the type and volume of extraction solvent, the type and concentration of surfactant, sample pH, and the concentration of salt added to the sample were investigated and opted. Under the optimum conditions (extraction solvent and its volume, 1-octanol, 70 µL; surfactant and its concentration, 1 mL of ultra-pure water containing 2 mmol L-1 cetyltrimethyl ammonium bromide; sample pH = 9 and salt content of 10% NaCl w/v), the preconcentration factors were obtained in the range of 202-241 and 246-265 for nitrazepam and lorazepam, respectively. The limits of quantification for both drugs were 5 µg L-1 in water sample and 10 µg L-1 in biological fluids with R2 values higher than 0.993. The suitability of the proposed method was successfully confirmed by the extraction and determination of the target drugs in human urine and plasma samples in the range of microgram per liter.

Polypyrrole/magnetic nanoparticles composite as an efficient sorbent for dispersive micro-solid-phase extraction of antidepressant drugs from biological fluids.

In this study, polypyrrole/magnetic nanoparticles composites in the presence of two different dopants were synthesized with the aid of chemical oxidative polymerization process for dispersive-µ-solid phase extraction (D-µ-SPE). The synthesized magnetic sorbents were characterized by various techniques. The results exhibited that the nanocomposite modified by polypyrrole with sodium perchlorate as a dopant demonstrated higher extraction efficiency for citalopram (CIT) and sertraline (STR) as the model compounds. This nanosorbent in combination with high performance liquid chromatography-UV detection was applied for extraction, preconcentration and determination of CIT and STR in urine and plasma samples. The effect of various parameters on the extraction efficiency including: sample pH, amount of sorbent, sorption time, eluent and its volume, salt content, and elution time were investigated and optimized. The opted conditions were: sample pH, 9.0; sorbent dosage, 10mg; sorption time, 7 min; elution solvent and its volume, 0.06 mol L(-1) HCl in methanol, 120 µL; elution time, 2 min and without addition of salt to the sample. The calibration curves were linear in the concentration range of 1-800 µg L(-1). The limits of detection (LODs) were obtained in the range of 0.2-1.0 µg L(-1) for CIT and 0.3-0.7 µg L(-1) for STR, respectively. The percent of extraction recoveries and relative standard deviations (n=5) were in the range of 93.4-99, 4.8-8.4 for CIT and 94-98.4, 4.3-9.2 for STR, respectively. Finally, the applicability of the method was successfully confirmed by the extraction and determination of CIT and STR in human urine and plasma samples.